Invasive plant time bombs: A hidden ecological threat

Invasive plants can stay dormant for decades or even centuries after they have been introduced into an environment before rapidly expanding and wreaking ecological havoc, according to a new study led by the University of California, Davis.

The research, published in Nature Ecology and Evolution, looked at more than 5,700 species of invasive plants in nine regions around the globe. It represents the most comprehensive analysis of plant invasions conducted to date, said senior author Mohsen Mesgaran, an assistant professor in the Department of Plant Sciences at UC Davis.

"The longer it is dormant, we're more likely to ignore it," Mesgaran said. "This latency allows them to be overlooked, contributing to their eventual emergence as a serious invasive threat. They're like invasive time bombs."

Long periods of dormancy

The international team found that nearly one-third of the invasive plants they analyzed exhibited lag periods between introduction and rapid expansion, with the average time being 40 years. The longest dormant period -- sycamore maples in the United Kingdom -- was 320 years.

Consider the common lawn weed Plantago lanceolata, otherwise known as ribwort or buckhorn plantain, which has the longest dormancy in the United States, according to the report. Noxious to livestock and native plants, the plant was introduced in the United States in 1822 and is found widely here. Velvetleaf, which was introduced as a possible fiber crop, can be dormant for 50 years before it expands, threatening corn, soybean and other crops as it sucks up water and nutrients.

Nonnative species are generally introduced in two ways: by accident or through intentional importation for medicinal, ornamental, agricultural and other purposes. In California, about 65% of invasive plants were knowingly introduced.

"This lag phase may have played a role," Mesgaran said. "They didn't know. With an increase in trade and transportation and tourism we're going to have more problems."

Global herbaria

The researchers generated a list of invasive plants in Australia, Great Britain, Ireland, Japan, New Zealand, Madagascar, South Africa, Japan and the United States and used herbaria records, which are digitized and accessible online, to obtain global data on the location and time of species observations.

They then looked at trends to determine whether species exhibited dormant phases and, if so, for how long. A time series analysis was applied to detect lag periods, followed by a second analysis that compared climate during dormant and expansion phases.

In some of the species that invaded different regions, dormancy periods varied by location. In 90% of cases, climate conditions were different during times when the species spread, suggesting the plants waited for the right conditions or adapted to survive to an environment that was once unsuitable, Mesgaran said.

Planning for the future

Knowing that problems could loom in the future is key to managing pests and preventing widespread invasion and economic losses down the road. That means growers, policymakers and others should consider dormancy periods.

"The problem is most of the models that we have for risk assessment to see if the species are going to be invasive and a pest problem in the future don't account for this lag phase or this dormant phase," Mesgaran said. "It's not that they're not going to be a problem, it's just the calm before the storm."

The next steps in the research will be to examine the native climate of invasive species relative to conditions in these newer locations.

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Diverse forests hold huge carbon potential, as long as we cut emissions

Research results published in the journal, Nature, show that realistic global forest carbon potential is approximately 226 Gigatonnes (Gt) of carbon. The study, which involved hundreds of scientists around the world, highlights the critical importance of forest conservation, restoration, and sustainable management in moving towards international climate and biodiversity targets. The researchers stress that this potential can be achieved by incentivizing community-driven efforts to promote biodiversity.

The forest carbon potential has been a highly controversial topic. Four years ago, a study published in the journal Science found that the restoration of forests could capture over 200 Gt of carbon -- which could draw down approximately 30 percent of excess anthropogenic carbon. While this study elevated a discussion about the role of nature in fighting climate change, it also raised concerns around the adverse environmental impacts of mass tree plantations, carbon offsetting schemes, and greenwashing. While some scientific studies have supported the scale of this finding, others argued that this forest carbon estimate could be up to 4 or 5 times too high.

To address this controversial topic an international team of hundreds of researchers led by the Crowther Lab at ETH Zurich joined forces to build an integrated assessment using a comprehensive range of approaches, including vast ground-sourced data and satellite datasets.

Achieving forest carbon potential

Due to ongoing deforestation, the total amount of carbon stored in forests is ~328 Gt below its natural state. Of course, much of this land is used for extensive human development including urban and agricultural land. However, outside of those areas, researchers found that forests could capture approximately 226 Gt C in regions with a low human footprint if they were allowed to recover. Approximately 61 percent of this potential can be achieved by protecting existing forests, so that they can recover to maturity. The remaining 39 percent can be achieved by reconnecting fragmented forest landscapes through sustainable ecosystem management and restoration.

"Most of the world's forests are highly degraded. In fact, many people have never been in one of the few old growth forests that remain on Earth," said Lidong Mo, a lead author of the study. "To restore global biodiversity, ending deforestation must be a top priority."

The dataset revealed that biodiversity accounts for approximately half of the global forest productivity. As such, the researchers highlighted that, to achieve the full carbon potential, restoration efforts should include a natural diversity of species. In addition, sustainable agricultural, forestry, and restoration practices that promote biodiversity have the greatest potential for carbon capture.

Redefining restoration

The authors stress that responsible restoration is a fundamentally social endeavour. It includes countless actions such as conservation, natural regeneration, rewilding, silviculture, agroforestry, and all other community-driven efforts to promote biodiversity. It requires equitable development, driven by policies that prioritize the rights of local communities and Indigenous people.

"We need to redefine what restoration means to many people," said Thomas Crowther, the senior author of the paper and a professor at ETH Zurich. "Restoration is not about mass tree plantations to offset carbon emissions. Restoration means directing the flow of wealth towards millions of local communities, Indigenous populations, and farmers that promote biodiversity across the globe. Only when healthy biodiversity is the preferred choice for local communities will we get long-term carbon capture as a biproduct."

The researchers conclude that ecologically responsible forest restoration does not include the conversion of other ecosystems that would not naturally contain forests. "Global restoration is not only about trees," said Constantin Zohner, a senior researcher at ETH Zurich. "We have to protect natural biodiversity in all ecosystems including grasslands, peatlands, and wetlands that are equally essential for life on Earth."

Nature for climate

This study brings to light the critical importance of natural, diverse forests in contributing to 30 percent of carbon drawdown potential. However, forests cannot be a substitute for cutting fossil fuel emissions. If emissions continue to rise, the study warns, then on-going droughts, fires, and warming will threaten forests and limit their ability to absorb carbon.

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Heredity and environment account for people's love of nature

Humans have a positive view of nature. But is this due to an approach we have learned while growing up, or is it something we are born with? The answer is 'Both', according to researchers at the University of Gothenburg and the Swedish University of Agricultural Sciences. Our love of nature is highly individual and should influence how we plan our cities, say the researchers.

It is well known that nature has a positive effect on people. In cities in particular, studies have shown that trees and other greenery contribute to people's wellbeing. However, experts do not agree on the reasons behind this phenomenon, known as biophilia.

Some believe that it is natural for humans to feel an automatic positive attachment because human development has occurred in nature. Others argue that there is no evidence for this, and that influences during our childhood determine how we view nature.

A wide range of factors involved

Researchers from the University of Gothenburg and the Swedish University of Agricultural Sciences (SLU) have reviewed several studies within this field that examine both innate factors and what individuals experience during their lives, primarily as children. In a new scientific article, the researchers conclude that both heredity and environment influence an individual's attitude to nature, but that a wide range of factors also influence how love of nature is expressed.

"We have been able to establish that many people have an unconscious positive experience of nature," says Bengt Gunnarsson, Professor Emeritus of Environmental Science at the University of Gothenburg. "But the biophilia hypothesis should be modified to link the variation in individuals' relationships with nature to an interaction between heredity and environmental influence."

Nature mean different things

This is because people react differently to nature. In a Japanese study, subjects were asked to walk in a forest and in a city while their heartbeat was measured. This showed that positive emotions while walking in a forest increased in 65% of people. Thus, far from everyone had a positive perception of nature. Another environmental psychology study found that research subjects are unconsciously drawn to nature instead of cities, and that this attraction was reinforced in those whose childhood was rich in nature.

"An additional study on identical and non-identical twins showed that a genetic component influences an individual's positive or negative relationship with nature," continues Bengt. "But the study also highlighted the importance of environment in terms of attitudes towards nature."

Moreover, nature can mean completely different things to different people. Some enjoy parks with lawns and planted trees, while others prefer being in the wilderness. The researchers believe that this variation is also determined by both heredity and environment.

"So it's important that we don't standardise nature when planning greenery in our towns and cities," adds Marcus Hedblom, a researcher at SLU and co-author of the article. "We shouldn't replace wild greenery with a park and assume that it will be good for everyone."

Urban nature brings many benefits

In today's urban planning, densification has been a common way to achieve a more sustainable city. This can sometimes come into conflict with efforts to offer nature in cities. A large number of studies suggest that urban parks and green spaces contribute to increased physical activity and recovery from stress. The greenery in our cities is also important in other respects. Trees can clean the air and provide shade to create a tolerable urban climate on hot days.

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Fossil study sheds light on famous spirals found in nature

Leaf arrangements in the earliest plants differ from most modern plants, overturning a long-held theory regarding the origins of a famous mathematical pattern found in nature, research shows.

The findings indicate that the arrangement of leaves into distinctive spirals, that are common in nature today, were not common in the most ancient land plants that first populated the earth's surface.

Instead, the ancient plants were found to have another type of spiral. This negates a long held theory about the evolution of plant leaf spirals, indicating that they evolved down two separate evolutionary paths.

Whether it is the vast swirl of a hurricane or the intricate spirals of the DNA double-helix, spirals are common in nature and most can be described by the famous mathematical series the Fibonacci sequence.

Named after the Italian mathematician, Leonardo Fibonacci, this sequence forms the basis of many of nature's most efficient and stunning patterns.

Spirals are common in plants, with Fibonacci spirals making up over 90% of the spirals. Sunflower heads, pinecones, pineapples and succulent houseplants all include these distinctive spirals in their flower petals, leaves or seeds.

Why Fibonacci spirals, also known as nature's secret code, are so common in plants has perplexed scientists for centuries, but their evolutionary origin has been largely overlooked.

Based on their widespread distribution it has long been assumed that Fibonacci spirals were an ancient feature that evolved in the earliest land plants and became highly conserved in plants.

However, an international team led by the University of Edinburgh has overthrown this theory with the discovery of non-Fibonacci spirals in a 407-million-year old plant fossil.

Using digital reconstruction techniques the researchers produced the first 3D models of leafy shoots in the fossil clubmoss Asteroxylon mackiei -- a member of the earliest group of leafy plants.

The exceptionally preserved fossil was found in the famous fossil site the Rhynie chert, a Scottish sedimentary deposit near the Aberdeenshire village of Rhynie.

The site contains evidence of some of the planet's earliest ecosystems -- when land plants first evolved and gradually started to cover the earth's rocky surface making it habitable.

The findings revealed that leaves and reproductive structures in Asteroxylon mackiei, were most commonly arranged in non-Fibonacci spirals that are rare in plants today.

This transforms scientists understanding of Fibonacci spirals in land plants. It indicates that non-Fibonacci spirals were common in ancient clubmosses and that the evolution of leaf spirals diverged into two separate paths.

The leaves of ancient clubmosses had an entirely distinct evolutionary history to the other major groups of plants today such as ferns, conifers and flowering plants.

The team created the 3D model of Asteroxylon mackiei, which has been extinct for over 400 million years, by working with digital artist Matt Humpage, using digital rendering and 3D printing.

The research, published in the journal Science, was funded by UK Research and Innovation (UKRI), The Royal Society and the German Research Foundation.

The study also involved researchers from, University College Cork, Ireland, University Münster, Germany and Northern Rogue Studios, UK.

Dr Sandy Hetherington, an evolutionary palaeobiologist and the project's lead at the University of Edinburgh, said:

"Our model of Asteroxylon mackiei lets us examine leaf arrangement in 3D for the first time. The technology to 3D print a 407-million-year old plant fossils and hold it in your hand is really incredible.

"Our findings give a new perspective on the evolution of Fibonacci spirals in plants."

Holly-Anne Turner, who worked on the project as an undergraduate student at the University of Edinburgh and is first author of the study, said:

"The clubmoss Asteroxylon mackiei is one of the earliest examples of a plant with leaves in the fossil record.

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Perfection: The Enemy of Evolution

Scientists are often trained to seek out the absolute best solution to a given problem. On a chalk board, this might look something like drawing a graph to find a function's minimum or maximum point. When designing a turbojet engine, it might mean tweaking the rotor blades' angles a tiny degree to achieve a tenth of a percent increase in efficiency.

Adrian Bejan, the J.A. Jones Distinguished Professor of Mechanical Engineering at Duke University, was busy demonstrating the former for a class full of students when a thought struck him: this is not how nature operates. Evolution is a sequence of design changes happening on their own in a discernible direction; it never weds itself to a single point on a drawing board. An evolving system or animal is free to simply go with what works. Not so much that its performance suffers greatly, but enough that it opens access to other options near the so-called optimal design.

With science often looking to nature for clues to solve challenges, Bejan wondered if he might look the opposite way, to predict nature before looking at it. If problem solvers and builders were free to miss the absolute highest mark, how much greater might be the range of designs they consider plausible?

That's the question that Bejan posits in a new paper published online May 16 in the journal Biosystems. Using two relatively simple examples -- walkways ferrying passengers off a train and a bird flapping its wings -- he discovers that the answer is, "quite a lot."

"In engineering, design, theater, architecture or even the organization of this university, any form of design benefits from the ability to make good but imperfect decisions and the freedom to move on and contemplate other opportunities for improvement," Bejan said. "If one is wedded to the idea of the absolute best, nothing new will ever be created."

In the paper, Bejan first looks at the example of passengers arriving by train and walking across a room with many exit points. With the total area of the room remaining constant but the length and width of the room free to change, he solves for the optimal shape of the room to get all passengers where they're going the quickest. With the solution equations in hand, he shows that providing even 1% wiggle room for imperfection away from the best performance opens the design space by 28%.

In his second example, Bejan looks at the flapping motion of birds at nearly constant altitude and speed. Considering the various forces involved -- drag during gliding, lift created by wing size, speed and body size, among others -- he formulates an equation for the rhythm of wings needed to maintain constant speed with minimum effort. While an optimal answer does exist, Bejan once again shows that allowing for just 1% imperfection above the theoretical minimum effort opens the design space by 20%.

Bejan says that he chose these examples because they involved changing only a single variable, a single degree of freedom -- the shape for a room or the flapping rhythm for a wing. In more complex examples that involve many variables, these tiny tolerances for imperfection create an even wider range of "good enough" solutions.

The lesson learned is that science now has a predictive idea of how nature works. By focusing less on finding absolute optimal designs, researchers may use the freedom to iteratively move toward entirely new design concepts that wouldn't otherwise have been within their sight. It also gives designs, methods and entire fields of study the ability to adapt to a changing world.

Read more at Science Daily

A new model offers an explanation for the huge variety of sizes of DNA in nature

A new model developed at Tel Aviv University offers a possible solution to the scientific question of why neutral sequences, sometimes referred to as "junk DNA," are not eliminated from the genome of living creatures in nature and continue to exist within it even millions of years later.

According to the researchers, the explanation is that junk DNA is often located in the vicinity of functional DNA. Deletion events around the borders between junk and functional DNA are likely to damage the functional regions and so evolution rejects them. The model contributes to the understanding of the huge variety of genome sizes observed in nature.

The phenomenon that the new model describes is called by the team of researchers "border induced selection." It was developed under the leadership of the PhD student Gil Loewenthal in the laboratory of Prof. Tal Pupko from the Shmunis School of Biomedicine and Cancer Research, Faculty of Life Sciences and in collaboration with Prof. Itay Mayrose (Faculty of Life Sciences, Tel Aviv University). The study was published in the journal Open Biology.

The researchers explain that throughout evolution, the size of the genome in living creatures in nature changes. For example, some salamander species have a genome ten times larger than the human genome.

Prof. Pupko explains: "The rate of deletions and short insertions, which are termed in short as 'indels', is usually measured by examining pseudogenes. Pseudogenes are genes that have lost their function, and in which there are frequent mutations, including deletions and insertions of DNA segments. In previous studies that characterized the indels, it was found that the rate of deletions is greater than the rate of additions in a variety of creatures including bacteria, insects, and even mammals such as humans. The question we tried to answer is how the genomes are not deleted when the probability of DNA deletion events is significantly greater than DNA addition events."

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Humans and nature: The distance is growing

The idea that humans are facing a global extinction of experience of nature is popular, but there is poor empirical evidence of its reality. To shed more light on this, the scientists measured how the average distance from an individual's home to the nearest area with low human impact changed in the last decade. They found that humans currently live 9.7 km away from a natural area on average, which is 7% further away than in the year 2000. Europe and East Asia have the highest average distance to natural areas, such as 22 km in Germany and 16 km in France. "What is striking is that all other countries in the world are following a similar pattern," explains first author Dr Victor Cazalis, a postdoctoral researcher at iDiv and Leipzig University.

The authors also showed that tree cover within cities has declined worldwide since 2000, particularly in Central Africa and South-East Asia. "This finding suggests that the possibility for the urban population to access green spaces is reducing as well," concludes Dr Gladys Barragan-Jason, a researcher at the Theoretical and Experimental Ecology Station and co-author of the study. "Indeed, the study reveals that the destruction of natural areas combined with a strong increase in urban population is leading to a growing spatial distance between humans and nature, especially in Asia, Africa and South America."

In the same study, the authors systematically searched for scientific publications assessing a trend in experiences of nature: from direct ones such as hiking in national parks, to vicarious experiences like natural settings in cultural products like cartoons, computer games or books. They found that the number of studies assessing these trends was very low (N=18), with a strong bias towards the US, Europe and Japan. This shows that any claim about the extinction of nature experience is based on poor evidence and that more studies should investigate this question, especially in Africa, Latin America and Asia.

The 18 studies found by the authors show for instance a decline in visits to nature parks in the US and Japan, a decrease in camping activities in the US, and a decrease in the number of flower species observed by Japanese children. They also find signs of disconnection in the depletion of natural elements in novels, songs, children's albums and animated movies, which are less and less imbued with natural imagery (as shown e.g. by an iDiv study from 2021).

Despite these examples of decline, other interactions are stagnating or even increasing. Watching wildlife documentaries or interacting with wild animals in video games is, for example, more common than a few years ago. "New ways of digitally interacting with nature have certainly emerged or increased in recent decades," says Gladys Barragan-Jason. "But several former studies show that these interactions have a lesser effect on our sense of connection with nature than direct interaction."

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Planting trees can save lives, study shows

In the past 30 years, the non-profit organization Friends of Trees planted trees along the streets of Portland, Oregon. Now, a new study shows that each tree planted was associated with significant reductions in non-accidental and cardiovascular mortality (of 20% and 6%, respectively, for trees planted in the preceding 15-30 years). The researchers also estimate that the annual economic benefits of planting trees greatly exceed the cost of maintaining them. The study, co-led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by the "la Caixa" Foundation, together with the USDA Forest Service, was published in Environment International.

Evidence pointing to an association between exposure to nature and lower mortality is accumulating. "However, most studies use satellite imaging to estimate the vegetation index, which does not distinguish different types of vegetation and cannot be directly translated into tangible interventions," says Payam Dadvand, ISGlobal researcher and senior author of the study.

Thus, the authors took advantage of a natural experiment that took place in the city of Portland: between 1990 and 2019, Friends of Trees planted 49,246 street trees (and kept records of where the trees were planted, and when). So, the research team looked at the number of trees planted in a given area (specifically, a census track, where approximately 4,000 people live) in the preceding 5, 10 or 15 years. They associated this information with mortality due to cardiovascular, respiratory or non-accidental causes in that same area, using data from the Oregon Health Authority.

The results show that in neighbourhoods in which more trees had been planted, mortality rates (deaths per 100,000 persons) were lower. This negative association was significant for cardiovascular and non-accidental mortality (that is, all causes excluding accidents), particularly for males and people over the age of 65.

Furthermore, the association got stronger as trees aged and grew: the reduction in mortality rate associated with trees planted 11-15 years before (30%) was double that observed with trees planted in the preceding 1-5 years (15%). This means that older trees are associated with larger decreases in mortality, and that preserving existing mature trees may be particularly important for public health.

This study doesn't provide a direct insight into how trees improve health. However, the finding that large trees have a greater health impact than smaller ones is telling, because larger trees are better at absorbing air pollution, moderating temperatures, and reducing noise (three factors linked to increased mortality).

"We observed the effect both in green and less green neighbourhoods, which suggests that street tree planting benefits both," says Geoffrey H. Donovan, from the USDA Forest Service and first author of the study. The analysis took into account other factors that may influence mortality, such as income, education and racial composition of the neighbourhoods.

Finally, according to the authors' estimates, the benefits of tree planting greatly outweigh the cost: the annual cost of planting and maintaining one urban tree in each of Portland's 140 census tract areas would range somewhere between 3,000 and 13,000 USD, while it would generate around 14.2 million USD annually in lives saved.

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Being in nature: Good for mind, body and nutrition

In late 2020, Canadian doctors made headlines for "prescribing nature," or recommended time outdoors based on research that suggests people who spent two or more hours in nature per week improved their health and wellbeing. Knowing this, transdisciplinary researchers from Drexel University investigated how nature relatedness -- simply feeling connected with the natural world -- benefits dietary diversity and fruit and vegetable intake, in a study recently published the American Journal of Health Promotion.

"Nature relatedness has been associated with better cognitive, psychological and physical health and greater levels of environmental stewardship. Our findings extend this list of benefits to include dietary intake," said Brandy-Joe Milliron, PhD, an associate professor in Drexel's College of Nursing and Health Professions and lead author of the publication. "We found people with higher nature relatedness were more likely to report healthful dietary intake, including greater dietary variety and higher fruit and vegetable consumption."

The research team surveyed over 300 adults in Philadelphia to measure their self-reported connection to nature, including their experience with and perspective of nature, and the foods and beverages they had consumed the previous day to assess their dietary diversity and estimate their daily fruit and vegetable consumption. Survey participants mirrored demographic characteristics (gender, income, education and race) of Philadelphia, as of the 2010 census. The data were collected between May and August 2017. The results of the survey showed that participants with a stronger connection to nature reported a more varied diet and ate more fruits and vegetables.

"This work can impact health promotion practices in two ways," said Milliron. "First, nature-based health promotion interventions may increase nature relatedness across the lifespan and potentially improve dietary intake. And second, augmenting dietary interventions with nature-based activities may lead to greater improvements in dietary quality."

The research team added that these findings highlight the potential for leveraging nature-based experiences or interventions such as incorporating green spaces or urban greening into city planning, integrating nature- and park-prescription programs into healthcare practices (similar to the Canadian model) and promoting nature-based experiences in the classroom settings, among many others.

But, the researchers noted, while improving dietary intake through nature-based interventions may be valuable, it is also complex.

Read more at Science Daily

Climate change: A threat to human wellbeing and health of the planet

Human-induced climate change is causing dangerous and widespread disruption in nature and affecting the lives of billions of people around the world, despite efforts to reduce the risks. People and ecosystems least able to cope are being hardest hit, said scientists in the latest Intergovernmental Panel on Climate Change (IPCC) report, released today.

"This report is a dire warning about the consequences of inaction," said Hoesung Lee, Chair of the IPCC. "It shows that climate change is a grave and mounting threat to our wellbeing and a healthy planet. Our actions today will shape how people adapt and nature responds to increasing climate risks."

The world faces unavoidable multiple climate hazards over the next two decades with global warming of 1.5°C (2.7°F). Even temporarily exceeding this warming level will result in additional severe impacts, some of which will be irreversible. Risks for society will increase, including to infrastructure and low-lying coastal settlements.

The Summary for Policymakers of the IPCC Working Group II report, Climate Change 2022: Impacts, Adaptation and Vulnerability was approved on Sunday, February 27 2022, by 195 member governments of the IPCC, through a virtual approval session that was held over two weeks starting on February 14.

Urgent action required to deal with increasing risks

Increased heatwaves, droughts and floods are already exceeding plants' and animals' tolerance thresholds, driving mass mortalities in species such as trees and corals. These weather extremes are occurring simultaneously, causing cascading impacts that are increasingly difficult to manage. They have exposed millions of people to acute food and water insecurity, especially in Africa, Asia, Central and South America, on Small Islands and in the Arctic.

To avoid mounting loss of life, biodiversity and infrastructure, ambitious, accelerated action is required to adapt to climate change, at the same time as making rapid, deep cuts in greenhouse gas emissions. So far, progress on adaptation is uneven and there are increasing gaps between action taken and what is needed to deal with the increasing risks, the new report finds. These gaps are largest among lower-income populations.

The Working Group II report is the second instalment of the IPCC's Sixth Assessment Report (AR6), which will be completed this year.

"This report recognizes the interdependence of climate, biodiversity and people and integrates natural, social and economic sciences more strongly than earlier IPCC assessments," said Hoesung Lee. "It emphasizes the urgency of immediate and more ambitious action to address climate risks. Half measures are no longer an option."

Safeguarding and strengthening nature is key to securing a liveable future

There are options to adapt to a changing climate. This report provides new insights into nature's potential not only to reduce climate risks but also to improve people's lives.

"Healthy ecosystems are more resilient to climate change and provide life-critical services such as food and clean water," said IPCC Working Group II Co-Chair Hans-Otto Pörtner. "By restoring degraded ecosystems and effectively and equitably conserving 30 to 50 per cent of Earth's land, freshwater and ocean habitats, society can benefit from nature's capacity to absorb and store carbon, and we can accelerate progress towards sustainable development, but adequate finance and political support are essential."

Scientists point out that climate change interacts with global trends such as unsustainable use of natural resources, growing urbanization, social inequalities, losses and damages from extreme events and a pandemic, jeopardizing future development.

"Our assessment clearly shows that tackling all these different challenges involves everyone -- governments, the private sector, civil society -- working together to prioritize risk reduction, as well as equity and justice, in decision-making and investment," said IPCC Working Group II Co-Chair Debra Roberts.

"In this way, different interests, values and world views can be reconciled. By bringing together scientific and technological know-how as well as Indigenous and local knowledge, solutions will be more effective. Failure to achieve climate resilient and sustainable development will result in a sub-optimal future for people and nature."

Cities: Hotspots of impacts and risks, but also a crucial part of the solution

This report provides a detailed assessment of climate change impacts, risks and adaptation in cities, where more than half the world's population lives. People's health, lives and livelihoods, as well as property and critical infrastructure, including energy and transportation systems, are being increasingly adversely affected by hazards from heatwaves, storms, drought and flooding as well as slow-onset changes, including sea level rise.

"Together, growing urbanization and climate change create complex risks, especially for those cities that already experience poorly planned urban growth, high levels of poverty and unemployment, and a lack of basic services," Debra Roberts said.

"But cities also provide opportunities for climate action -- green buildings, reliable supplies of clean water and renewable energy, and sustainable transport systems that connect urban and rural areas can all lead to a more inclusive, fairer society."

There is increasing evidence of adaptation that has caused unintended consequences, for example destroying nature, putting peoples' lives at risk or increasing greenhouse gas emissions. This can be avoided by involving everyone in planning, attention to equity and justice, and drawing on Indigenous and local knowledge.

A narrowing window for action

Climate change is a global challenge that requires local solutions and that's why the Working Group II contribution to the IPCC's Sixth Assessment Report (AR6) provides extensive regional information to enable Climate Resilient Development.

The report clearly states Climate Resilient Development is already challenging at current warming levels. It will become more limited if global warming exceeds 1.5°C (2.7°F). In some regions it will be impossible if global warming exceeds 2°C (3.6°F). This key finding underlines the urgency for climate action, focusing on equity and justice. Adequate funding, technology transfer, political commitment and partnership lead to more effective climate change adaptation and emissions reductions.

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Over 200 health journals call on world leaders to address 'catastrophic harm to health' from climate change

Over 200 health journals across the world have come together to simultaneously publish an editorial calling on world leaders to take emergency action to limit global temperature increases, halt the destruction of nature, and protect health.

While recent targets to reduce emissions and conserve biodiversity are welcome, they are not enough and are yet to be matched with credible short and longer term plans, it warns.

The editorial is published in leading titles from every continent including The BMJ, The Lancet, the New England Journal of Medicine, the East African Medical Journal, the Chinese Science Bulletin, the National Medical Journal of India, the Medical Journal of Australia, and 50 BMJ specialist journals including BMJ Global Health and Thorax.

Never have so many journals come together to make the same statement, reflecting the severity of the climate change emergency now facing the world.

The editorial is being published ahead of the UN General Assembly next week, one of the last international meetings taking place before the (COP26) climate conference in Glasgow, UK in November. This is a crucial moment to urge all countries to deliver enhanced and ambitious climate plans to honour the goals of the Paris Agreement, the international treaty on climate change adopted by 195 countries in 2015.

For decades, health professionals and health journals have been warning of the severe and growing impacts on health from climate change and the destruction of nature .

The impact on health and survival of extreme temperatures, destructive weather events, and the widespread degradation of essential ecosystems are just some of the impacts that we are seeing more of due to a changing climate.

They disproportionately affect the most vulnerable, including children and the elderly, ethnic minorities, poorer communities and those with underlying health conditions.

The editorial urges governments to intervene to transform societies and economies, for example, by supporting the redesign of transport systems, cities, production and distribution of food, markets for financial investments, and health systems.

Substantial investment will be needed, but this will have huge positive health and economic benefits, including high quality jobs, reduced air pollution, increased physical activity, and improved housing and diet, explain the authors.

Crucially, cooperation hinges on wealthy nations doing more, they say. In particular, countries that have disproportionately created the environmental crisis must do more to support low and middle income countries to build cleaner, healthier, and more resilient societies.

"As health professionals, we must do all we can to aid the transition to a sustainable, fairer, resilient, and healthier world," they write. "We, as editors of health journals, call for governments and other leaders to act, marking 2021 as the year that the world finally changes course."

Dr Fiona Godlee, Editor-in-Chief of The BMJ, and one of the co-authors of the editorial, said: "Health professionals have been on the frontline of the covid-19 crisis and they are united in warning that going above 1.5C and allowing the continued destruction of nature will bring the next, far deadlier crisis. Wealthier nations must act faster and do more to support those countries already suffering under higher temperatures. 2021 has to be the year the world changes course -- our health depends on it."

Seye Abimbola, Editor-in-Chief of BMJ Global Health, said: "What we must do to tackle pandemics, health inequities, and climate change is the same - global solidarity and action that recognise that, within and across nations our destinies are inextricably linked, just as human health is inextricably linked to the health of the planet."

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To design truly compostable plastic, scientists take cues from nature

Despite our efforts to sort and recycle, less than 9% of plastic gets recycled in the U.S., and most ends up in landfill or the environment.

Biodegradable plastic bags and containers could help, but if they're not properly sorted, they can contaminate otherwise recyclable #1 and #2 plastics. What's worse, most biodegradable plastics take months to break down, and when they finally do, they form microplastics -- tiny bits of plastic that can end up in oceans and animals' bodies -- including our own.

Now, as reported in the journal Nature, scientists at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley have designed an enzyme-activated compostable plastic that could diminish microplastics pollution, and holds great promise for plastics upcycling. The material can be broken down to its building blocks -- small individual molecules called monomers -- and then reformed into a new compostable plastic product.

"In the wild, enzymes are what nature uses to break things down -- and even when we die, enzymes cause our bodies to decompose naturally. So for this study, we asked ourselves, 'How can enzymes biodegrade plastic so it's part of nature?" said senior author Ting Xu , who holds titles of faculty senior scientist in Berkeley Lab's Materials Sciences Division, and professor of chemistry and materials science and engineering at UC Berkeley.

At Berkeley Lab, Xu -- who for nearly 15 years has dedicated her career to the development of functional polymer materials inspired by nature -- is leading an interdisciplinary team of scientists and engineers from universities and national labs around the country to tackle the mounting problem of plastic landfill posed by both single-use and so-called biodegradable plastics.

Most biodegradable plastics in use today are usually made of polylactic acid (PLA), a vegetable-based plastic material blended with cornstarch. There is also polycaprolactone (PCL), a biodegradable polyester that is widely used for biomedical applications such as tissue engineering.

But the problem with conventional biodegradable plastic is that they're indistinguishable from single-use plastics such as plastic film -- so a good chunk of these materials ends up in landfills. And even if a biodegradable plastic container gets deposited at an organic waste facility, it can't break down as fast as the lunch salad it once contained, so it ends up contaminating organic waste, said co-author Corinne Scown, a staff scientist and deputy director for the Research, Energy Analysis & Environmental Impacts Division in Berkeley Lab's Energy Technologies Area.

Another problem with biodegradable plastics is that they aren't as strong as regular plastic -- that's why you can't carry heavy items in a standard green compost bag. The tradeoff is that biodegradable plastics can break down over time -- but still, Xu said, they only break down into microplastics, which are still plastic, just a lot smaller.

So Xu and her team decided to take a different approach -- by "nanoconfining" enzymes into plastics.

Putting enzymes to work

Because enzymes are part of living systems, the trick would be carving out a safe place in the plastic for enzymes to lie dormant until they're called to action.

In a series of experiments, Xu and co-authors embedded trace amounts of the commercial enzymes Burkholderia cepacian lipase (BC-lipase) and proteinase K within the PLA and PCL plastic materials. The scientists also added an enzyme protectant called four-monomer random heteropolymer, or RHP, to help disperse the enzymes a few nanometers (billionths of a meter) apart.

In a stunning result, the scientists discovered that ordinary household tap water or standard soil composts converted the enzyme-embedded plastic material into its small-molecule building blocks called monomers, and eliminated microplastics in just a few days or weeks.

They also learned that BC-lipase is something of a finicky "eater." Before a lipase can convert a polymer chain into monomers, it must first catch the end of a polymer chain. By controlling when the lipase finds the chain end, it is possible to ensure the materials don't degrade until being triggered by hot water or compost soil, Xu explained.

In addition, they found that this strategy only works when BC-lipase is nanodispersed -- in this case, just 0.02 percent by weight in the PCL block -- rather than randomly tossed in and blended.

"Nanodispersion puts each enzyme molecule to work -- nothing goes to waste," Xu said.

And that matters when factoring in costs. Industrial enzymes can cost around $10 per kilogram, but this new approach would only add a few cents to the production cost of a kilogram of resin because the amount of enzymes required is so low -- and the material has a shelf life of more than 7 months, Scown added.

The proof is in the compost

X-ray scattering studies performed at Berkeley Lab's Advanced Light Source characterized the nanodispersion of enzymes in the PCL and PLA plastic materials.

Interfacial-tension experiments conducted by co-author Tom Russell revealed in real time how the size and shape of droplets changed as the plastic material decomposed into distinct molecules. The lab results also differentiated between enzyme and RHP molecules.

"The interfacial test gives you information about how the degradation is proceeding," he said. "But the proof is in the composting -- Ting and her team successfully recovered plastic monomers from biodegradable plastic simply by using RHPs, water, and compost soil."

Russell is a visiting faculty scientist and professor of polymer science and engineering from the University of Massachusetts who leads the Adaptive Interfacial Assemblies Towards Structuring Liquids program in Berkeley Lab's Materials Sciences Division.

Developing a very affordable and easily compostable plastic film could incentivize produce manufacturers to package fresh fruits and vegetables with compostable plastic instead of single-use plastic wrap -- and as a result, save organic waste facilities the extra expense of investing in expensive plastic-depackaging machines when they want to accept food waste for anaerobic digestion or composting, Scown said.

Since their approach could potentially work well with both hard, rigid plastics and soft, flexible plastics, Xu would like to broaden their study to polyolefins, a ubiquitous family of plastics commonly used to manufacture toys and electronic parts.

The team's truly compostable plastic could be on the shelves soon. They recently filed a patent application through UC Berkeley's patent office. And co-author Aaron Hall, who was a Ph.D. student in materials science and engineering at UC Berkeley at the time of the study, founded UC Berkeley startup Intropic Materials to further develop the new technology. He was recently selected to participate in Cyclotron Road, an entrepreneurial fellowship program in partnership with Activate.

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Effective Field Theories and the nature of the universe

Effective Field Theories were introduced to simplify the mathematics involved in unifying interactions into the Standard Model of particle physics. An article in EPJ H presents Nobel Laureate Steven Weinberg's recent lecture on the development of these theories.

What is the world made of? This question, which goes back millennia, was revisited by theoretical physicist Steven Weinberg from the University of Texas in Austin, TX, USA in the first of an international seminar series, 'All Things EFT'. Weinberg's seminar has now been published as an article in the journal EPJ H.

And Weinberg is well placed to discuss both Effective Field Theories (EFTs) and the nature of the Universe, as he shared the 1979 Nobel Prize for Physics for developing a theory to unify the weak and electromagnetic interactions between elementary particles. This fed into the development of the widely used Standard Model of particle physics that unifies these two forces with the strong interaction.

The introduction to the article describes Weinberg as the 'pioneer' of EFTs. In his wide-ranging talk, Weinberg sets out the early history of EFTs from a personal perspective and describes some implications for future research.

Briefly, an EFT is a type of theory or approximation that describes a physical phenomenon at given length or energy scales, while averaging over shorter length or higher energy scales. Weinberg describes how the unifying Standard Model came to be seen as a valid approximation to a more fundamental theory that will likely take over at the highest energies, such as string theory.

He remembers how physicists of 1950s and 1960s had difficulty linking quantum field theory to the strong interaction. Eventually, he and others produced a standardised methodology that could fit observed data at least as well as the rather cumbersome mathematics that was being used. These ideas can be generalised; eventually, he states, 'all [physicists'] theories will survive as approximations to a future theory'.

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Nature conservation policy rarely changes people's behavior

 It is a well-known problem: too rarely do nature conservation initiatives, recommendations or strategies announced by politicians lead to people really changing their everyday behaviour. A German-Israeli research team led by the Helmholtz Centre for Environmental Research (UFZ) and the German Centre for Integrative Biodiversity Research (iDiv) has investigated the reasons for this. According to the team, the measures proposed by politicians do not sufficiently exploit the range of possible behavioural interventions and too rarely specify the actual target groups, they write in the journal Conservation Biology.

The protection of pollinating insects is a major issue in international nature conservation policy. Stirred up by scientific findings on high population losses of insect groups such as bees or butterflies, which, for example, affect pollination services in agriculture, Europe is putting insect protection at the forefront of environmental policy. Many governments in Europe have presented national strategies to ensure that pollinators are maintained. A team of researchers from UFZ, iDiv and Technion -- Israel Institute of Technology analysed the available eight national strategy papers to protect pollinators in terms of behavioural change interventions. The result: "Nature conservation policies to preserve pollinators are often too ineffective in this respect and change little in people's behaviour," says first author and environmental psychologist Dr. Melissa Marselle, who is conducting research at the UFZ and iDiv on the impact of biodiversity on human health.

The scientists coded around 610 behavioural measures in the strategy papers. Using the "Behaviour Change Wheel" theory, which originates from health psychology and integrates 19 different behavioural models, the scientists categorized the behavioural measures for pollinator conservation into the nine different types of interventions -- i.e. measures that could change people's behaviour. According to this, most of the 790 or so behavioral measures for pollinator conservation (23 percent) can be assigned to the behaviour change interventions of education and awareness raising, followed by structural measures such as planting hedges, sowing flower strips in fields or creating green spaces in the city (19 percent). Only around four percent of the behavioural measures for pollinator conservation can be summarized under the intervention of modeling, for example, peer-to-peer learning or the use of best-practice examples from farmers who work in exemplary fashion. Other little-mentioned behavioural interventions for pollinator conservation were incentive systems for farmers or municipalities (three percent) and statutory regulations (two percent). Interventions that create a financial cost to discourage a certain behaviour, such as additional taxes on the use of pesticides, did not appear in any of the policy papers for pollinator conservation.

"This shows that national biodiversity strategies focus primarily on educational and structural measures and neglect other effective instruments," says Melissa Marselle. "Educational measures to impart knowledge and to create understanding are important. But relying on education alone is not very effective if you really want to change environmental behaviour. It would be more effective to link it to a wider range of other measures." For example, clearly identifying supply chains and producer principles on labels can encourage many people to buy an organic or pollinator-friendly products -- even at a higher price. Stronger financial incentives for farmers who operate sustainably would also be effective, and the certification of sustainable buildings could be linked to the use of pollinator-friendly plants as flower beds. Taxes and additional costs for consumers also ensure rapid changes in behaviour: In the UK, for example, a compulsory levy on the purchase of plastic bags has led to a decline in their use.

A further shortcoming of the strategy papers was identified as the fact that in 41 percent of the behavioural measures for pollinator conservation the target groups whose behaviour needs to change were not named and specified. The objectives are often very well described, but mostly revolve around the question of how certain actions change the environment. However, it is often not defined in more detail to whom the actions are directed and who should implement them: the public, farmers or local authorities? It could be more effective to first consider what the different actors can do, with the help of behavioural researchers, and then, building on that, to consider measures to achieve certain goals.

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Reconnecting with nature key for the health of people and the planet

Individuals who visit natural spaces weekly, and feel psychologically connected to them, report better physical and mental wellbeing, new research has shown.

Alongside the benefits to public health, those who make weekly nature visits, or feel connected to nature, are also more likely to behave in ways which promote environmental health, such as recycling and conservation activities.

The findings of the study, published in the Journal of Environmental Psychology, indicate that reconnecting with nature could be key to achieving synergistic improvements to human and planetary health.

The study was conducted by researchers at the University of Plymouth, Natural England, the University of Exeter and University of Derby, and is the first to investigate -- within a single study -- the contribution of both nature contact and connection to human health, wellbeing and pro-environmental behaviours.

The findings are based on responses to the Monitor of Engagement with the Natural Environment (MENE) survey, commissioned by Natural England as part of DEFRA's social science research programme. The team looked at people's engagement with nature though access to greenspace, nature visits and the extent to which they felt psychologically connected to the natural world.

Lead author Leanne Martin, of the University of Plymouth, said: "In the context of increasing urbanisation, it is important to understand how engagement with our planet's natural resources relate to human health and behaviour. Our results suggest that physically and psychologically reconnecting with nature can be beneficial for human health and wellbeing, and at the same time encourages individuals to act in ways which protect the health of the planet."

Marian Spain, Chief Executive of Natural England added: "It's a top priority for Natural England to unlock the potential of the natural environment to help address the challenges we are facing as a society: poor physical health and mental wellbeing; the climate change crisis and the devastating loss of wildlife.

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Transformative change can save humans and nature

The survival of Earth's life is not a battle of humans versus nature. In this week's Science, an independent group of international experts, including one from Michigan State University (MSU), deliver a sweeping assessment of nature, concluding victory needs both humans and nature to thrive.

"Pervasive human-driven decline of life on Earth points to the need for transformative change" explores how human impacts on life on Earth are unprecedented, requiring transformative action to address root economic, social and technological causes.

It's a notable assessment not just for its unflinching examination of "living nature" -- Earth's fabric of life which provides food, water, energy and healthy security. The Science article "Pervasive human-driven decline of life on Earth points to the need for transformative change" takes up where the recent Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services Global Assessment (IPBES) leaves off by following an intergovernmental process from start to end. The report covers not only the history of humanity's interactions with nature -- with particular focus on the last 50 years -- but also how these might change in the future.

"We cannot save the planet -- and ourselves -- until we understand how tightly woven people and the natural benefits that allow us to survive are," said Jianguo "Jack" Liu, MSU Rachel Carson Chair in Sustainability and a co-author. "We have learned new ways to understand these connections, even as they spread across the globe. This strategy has given us the power to understand the full scope of a problem, which allows us to find true solutions."

Nature's capacity to provide beneficial regulation of environmental processes, such as modulating air and water quality, sequestering carbon, building healthy soils, pollinating crops, and providing coastal protection from hazards such as storms and storm surges, has decreased globally, but not evenly. Scientists, the paper notes, have gotten better collecting information and modeling situations to more accurately reflect how the world truly works.

Among that methodology increasingly adopted by scientists across the world is telecoupling, introduced by Liu in 2008 and the framework since applied to more than 500 scientific papers. The telecoupling framework is an integrative way to study coupled human and natural systems that are linked over long distances. The framework keeps both the humans and the natural in focus and shows how changes can reverberate far beyond, and then even double back.

Their group's dedication to integrative approaches has produced a litany of human impact: 70% of land surfaces altered, 77% of major rivers no longer flow from source to sea, the tally of animal species going extinct is rising, biodiversity is being lost.

The group applies different scenarios to see how plausible changes have an effect. Starkly, they note nothing on Earth ultimately wins in the "business as usual" scenario.

They say that what our planet needs -- quickly -- is transformative change. A new way of doing business, what they term "a system-wide reorganization across technological, economic and social factors, making sustainability the norm rather than the altruistic exception."

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Nature's dangerous decline 'unprecedented,' species extinction rates 'accelerating'

Pacific Ocean.

Nature is declining globally at rates unprecedented in human history -- and the rate of species extinctions is accelerating, with grave impacts on people around the world now likely, warns a landmark new report from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the summary of which was approved at the 7th session of the IPBES Plenary, meeting last week (29 April -- 4 May) in Paris.

"The overwhelming evidence of the IPBES Global Assessment, from a wide range of different fields of knowledge, presents an ominous picture," said IPBES Chair, Sir Robert Watson. "The health of ecosystems on which we and all other species depend is deteriorating more rapidly than ever. We are eroding the very foundations of our economies, livelihoods, food security, health and quality of life worldwide."

"The Report also tells us that it is not too late to make a difference, but only if we start now at every level from local to global," he said. "Through 'transformative change', nature can still be conserved, restored and used sustainably -- this is also key to meeting most other global goals. By transformative change, we mean a fundamental, system-wide reorganization across technological, economic and social factors, including paradigms, goals and values."

"The member States of IPBES Plenary have now acknowledged that, by its very nature, transformative change can expect opposition from those with interests vested in the status quo, but also that such opposition can be overcome for the broader public good," Watson said.

The IPBES Global Assessment Report on Biodiversity and Ecosystem Services is the most comprehensive ever completed. It is the first intergovernmental Report of its kind and builds on the landmark Millennium Ecosystem Assessment of 2005, introducing innovative ways of evaluating evidence.

Compiled by 145 expert authors from 50 countries over the past three years, with inputs from another 310 contributing authors, the Report assesses changes over the past five decades, providing a comprehensive picture of the relationship between economic development pathways and their impacts on nature. It also offers a range of possible scenarios for the coming decades.

Based on the systematic review of about 15,000 scientific and government sources, the Report also draws (for the first time ever at this scale) on indigenous and local knowledge, particularly addressing issues relevant to Indigenous Peoples and Local Communities.

"Biodiversity and nature's contributions to people are our common heritage and humanity's most important life-supporting 'safety net'. But our safety net is stretched almost to breaking point," said Prof. Sandra Díaz (Argentina), who co-chaired the Assessment with Prof. Josef Settele (Germany) and Prof. Eduardo S. Brondízio (Brazil and USA).

"The diversity within species, between species and of ecosystems, as well as many fundamental contributions we derive from nature, are declining fast, although we still have the means to ensure a sustainable future for people and the planet."

The Report finds that around 1 million animal and plant species are now threatened with extinction, many within decades, more than ever before in human history.

The average abundance of native species in most major land-based habitats has fallen by at least 20%, mostly since 1900. More than 40% of amphibian species, almost 33% of reef-forming corals and more than a third of all marine mammals are threatened. The picture is less clear for insect species, but available evidence supports a tentative estimate of 10% being threatened. At least 680 vertebrate species had been driven to extinction since the 16th century and more than 9% of all domesticated breeds of mammals used for food and agriculture had become extinct by 2016, with at least 1,000 more breeds still threatened.

"Ecosystems, species, wild populations, local varieties and breeds of domesticated plants and animals are shrinking, deteriorating or vanishing. The essential, interconnected web of life on Earth is getting smaller and increasingly frayed," said Prof. Settele. "This loss is a direct result of human activity and constitutes a direct threat to human well-being in all regions of the world."

To increase the policy-relevance of the Report, the assessment's authors have ranked, for the first time at this scale and based on a thorough analysis of the available evidence, the five direct drivers of change in nature with the largest relative global impacts so far. These culprits are, in descending order: (1) changes in land and sea use; (2) direct exploitation of organisms; (3) climate change; (4) pollution and (5) invasive alien species.

The Report notes that, since 1980, greenhouse gas emissions have doubled, raising average global temperatures by at least 0.7 degrees Celsius -- with climate change already impacting nature from the level of ecosystems to that of genetics -- impacts expected to increase over the coming decades, in some cases surpassing the impact of land and sea use change and other drivers.

Despite progress to conserve nature and implement policies, the Report also finds that global goals for conserving and sustainably using nature and achieving sustainability cannot be met by current trajectories, and goals for 2030 and beyond may only be achieved through transformative changes across economic, social, political and technological factors. With good progress on components of only four of the 20 Aichi Biodiversity Targets, it is likely that most will be missed by the 2020 deadline. Current negative trends in biodiversity and ecosystems will undermine progress towards 80% (35 out of 44) of the assessed targets of the Sustainable Development Goals, related to poverty, hunger, health, water, cities, climate, oceans and land (SDGs 1, 2, 3, 6, 11, 13, 14 and 15). Loss of biodiversity is therefore shown to be not only an environmental issue, but also a developmental, economic, security, social and moral issue as well.

"To better understand and, more importantly, to address the main causes of damage to biodiversity and nature's contributions to people, we need to understand the history and global interconnection of complex demographic and economic indirect drivers of change, as well as the social values that underpin them," said Prof. Brondízio. "Key indirect drivers include increased population and per capita consumption; technological innovation, which in some cases has lowered and in other cases increased the damage to nature; and, critically, issues of governance and accountability. A pattern that emerges is one of global interconnectivity and 'telecoupling' -- with resource extraction and production often occurring in one part of the world to satisfy the needs of distant consumers in other regions."

Other notable findings of the Report include:

• Three-quarters of the land-based environment and about 66% of the marine environment have been significantly altered by human actions. On average these trends have been less severe or avoided in areas held or managed by Indigenous Peoples and Local Communities.
• More than a third of the world's land surface and nearly 75% of freshwater resources are now devoted to crop or livestock production.
• The value of agricultural crop production has increased by about 300% since 1970, raw timber harvest has risen by 45% and approximately 60 billion tons of renewable and non-renewable resources are now extracted globally every year -- having nearly doubled since 1980.
• Land degradation has reduced the productivity of 23% of the global land surface, up to US$577 billion in annual global crops are at risk from pollinator loss and 100-300 million people are at increased risk of floods and hurricanes because of loss of coastal habitats and protection.
• In 2015, 33% of marine fish stocks were being harvested at unsustainable levels; 60% were maximally sustainably fished, with just 7% harvested at levels lower than what can be sustainably fished.
• Urban areas have more than doubled since 1992.
• Plastic pollution has increased tenfold since 1980, 300-400 million tons of heavy metals, solvents, toxic sludge and other wastes from industrial facilities are dumped annually into the world's waters, and fertilizers entering coastal ecosystems have produced more than 400 ocean 'dead zones', totalling more than 245,000 km2 (591-595) -- a combined area greater than that of the United Kingdom.
• Negative trends in nature will continue to 2050 and beyond in all of the policy scenarios explored in the Report, except those that include transformative change -- due to the projected impacts of increasing land-use change, exploitation of organisms and climate change, although with significant differences between regions.

The Report also presents a wide range of illustrative actions for sustainability and pathways for achieving them across and between sectors such as agriculture, forestry, marine systems, freshwater systems, urban areas, energy, finance and many others. It highlights the importance of, among others, adopting integrated management and cross-sectoral approaches that take into account the trade-offs of food and energy production, infrastructure, freshwater and coastal management, and biodiversity conservation.

Also identified as a key element of more sustainable future policies is the evolution of global financial and economic systems to build a global sustainable economy, steering away from the current limited paradigm of economic growth.

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Invasive plants have unprecedented ability to pioneer new continents and climates

Velvetleaf represents one of the many invasive plant species that was tested by Dan Atwater and Jacob Barney.

It's no secret that globalization, aided by climate change, is helping invasive species gain a foothold across the planet. What came as something of a surprise to Virginia Tech researchers was just how mutable these invaders are.

The scientists discovered that invasive plant species are not only highly adaptive, they are essentially able to change in order to thrive on new continents and in different types of climates, challenging the assumption that species occupy the same environment in native and invasive ranges.

The study, by Jacob Barney, an associate professor in the College of Agriculture and Life Sciences' Department of Plant Pathology, Physiology, and Weed Science and Dan Atwater, a lecturer in the Department of Biological Sciences at North Carolina State University and Barney's former post-doctoral advisee, was published Tuesday in Nature Ecology and Evolution, an online journal.

"This is important for both changing how we think about species and where they grow," said Barney, who is also a fellow in the Fralin Life Science Institute and an affiliate of the Global Change Center. "The findings also change our ability to predict where they will grow, and how they may respond in a changing climate. This could be a game-changer for invasive species risk assessment and conservation."

Atwater used data compiled by undergraduate Carissa Ervine, also an author on the paper, to test a long-held assumption in ecology -- that the climate limitations of plants do not change, which means we can predict where they will grow. Small studies supported this supposition. However, the Virginia Tech researchers blew this assumption away by testing more than 800 species using new models developed by Atwater and Barney.

"Some people would say that invasive species have different distributions in a new climate. But we found they are occupying a wider range of new climates," said Atwater. "Species are changing in their ecology when they move from one continent to another. We should expect species to change, possibly permanently, when they cross continents."

The results have major consequences for applying environmental niche models to assess the risk of invasive species and for predicting species' responses to climate change. Species capable of changing their ecology and the climates they call home may pose a challenge to researchers using native range data to forecast the distribution of invasive species.

The driver behind the study was a desire to forecast the future distribution of invasive species which pose a serious threat to human, environmental, and economic health. The researchers began by posing the question: Do invasive species occupy the same climate in invasive range that they do in their native range? To find out, they compared native and invasive species.

Barney and Atwater examined 815 terrestrial plant species from every continent, along with millions of occurrence points, or locations where the plants have been known to occur, and compared models in the largest global invasive species study to date. They found evidence of climatic niche shifts in all of the 815 plant species introduced across five continents. A climatic niche refers to the set of climates in which a species has a stable or growing population.

Generally, their findings suggest that niche shifts reflect changes in climate availability at the continent scale and were the largest in long-lived and cultivated species. If species move to a warmer continent, for instance, they tend to shift towards occupying warmer climates. In short, cultivated plants with long lifespans are particularly adept at making themselves home in brand new climates.

"There are not only implications for predicting where invasive species will occur, there are management repercussions as well," said Barney. "As an example, for certain species we use biocontrol, introducing one organism to control another, an approach that may not be effective or safe if the targeted species undergoes ecological change. When we do climate modeling, we assume the climate niche may be the same when it may not be. So, there are a broad range of implications in a broad range of fields."

Barney raised another concern.

"By cultivating species -- bending them for agricultural or ornamental purposes and selecting for traits such as cold-hardiness, we push them into environments they would not have occupied," he said. "Those selection pressures in breeding, plus the environments we put them in, may exaggerate this change. Short-lived species, for example, go into dryer climates. So the take home is that different species' traits influence the direction of a niche shift."

Once Atwater and Barney understand these drivers more fully, they hope to be able to predict how the geographic range of an invasive species will increase in order to pinpoint areas likely to be invaded.

"The other piece layered onto this is the assumption that the climate is stable, which is not the case," said Atwater. "We have also relied on the assumption that a species is a species and its ecological tendencies remain constant. This too is not the case. Species vary in space and time. They behave differently on different continents and in different climates. Consequently, the concept of a species climatic niche is less stable and less clearly defined."

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Radio 'eyes' unlocking secrets of neutron-star collision

VLA image of the radio emissions coming from the location where two neutron stars collided and generated gravitational waves. The emission from the collision site is the middle object in this image.

When a pair of superdense neutron stars collided and potentially formed a black hole in a galaxy 130 million light-years from Earth, they unleashed not only a train of gravitational waves but also an ongoing torrent of radio waves that are answering some of the biggest questions about the nature of such a cataclysmic event.

On August 17, the LIGO and VIRGO gravitational-wave observatories combined to locate the source of faint ripples in spacetime caused by the merger of the two neutron stars. This was only the fourth direct detection of gravitational waves, which were predicted more than a century ago by Albert Einstein's General Theory of Relativity. In this case, for the first time, electromagnetic radiation -- light, gamma rays, and radio waves -- were detected coming from the same object that emitted the gravitational waves.

"The story that now is unfolding is more complete than for any previous event in astronomical history. With information provided by both gravitational waves and electromagnetic waves, which are completely different phenomena, it's like being able to both see and hear the same event for the first time," said Gregg Hallinan, of Caltech.

"The gravitational waves confirmed that we're seeing the merger of two neutron stars, and the radio waves we're observing are going to answer important questions about how much energy was in the explosion, how much mass was ejected, and what kind of environment this explosion occurred in," said Alessandra Corsi, of Texas Tech University.

Hallinan, Corsi and collaborators coordinated various radio telescopes across the globe to observe the galaxy in which the explosion, called GW170817, occurred just a day after the gravitational waves were detected. The first detection of radio waves came from the National Science Foundation's Karl G. Jansky Very Large Array (VLA) on September 2. This radio discovery was made by the Jansky VLA mapping of Gravitational Wave bursts as Afterglows in Radio (JAGWAR) team, where Hallinan played a key role. Independent confirmation came subsequently from a smaller team led by Corsi, also observing with the VLA. The Australia Telescope Compact Array (ATCA) also detected radio emission from the object on September 5.

"This event is the first unambiguous detection of a merger of two neutron stars," said Dale Frail of the National Radio Astronomy Observatory (NRAO). "Such mergers are thought to be the cause of one type of Gamma Ray Burst, and we now have the opportunity to test the theories that have been proposed about how those bursts and their afterglows work," he added.

So far, the scientists said, the evidence provided by the radio observations indicates that the explosion either produced a jet of particles moving at nearly the speed of light that we are seeing at an angle widely separated from the jet's axis, or that there is a "cocoon" of material expanding more slowly from the explosion.

"The radio waves are still coming in, and will continue to do so for months or even years," Corsi said. "Their behavior over that time will tell us which story is correct."

In addition, the radio observations will tell the scientists how dense the environment around the explosion is, and into which the debris is expanding.

"Another exciting possibility is that if the radio emission is coming from a cocoon, we may be able to directly image it with high-resolution radio telescope systems using antennas separated by thousands of miles," said Kunal Mooley, of the University of Oxford in the UK, who is the principal investigator of the JAGWAR program. "We should know about this in just a few months."

"Radio telescopes now are our key to learning the physics of this explosion. The radio emission came late to the party, but it's the last to leave! We will continue to learn important facts about this event in the coming months," Hallinan said.

The object already has faded below the sensitivity limits of most ground-based telescopes except at radio wavelengths, where the VLA will continue to play a very important role.

"This event is our first look at the neutron-star collision process that creates heavy elements such as gold, which are included in the material moving outward from the explosion and producing the radio waves. That means that there is a little bit of neutron-star merger material in all of us," Mooley said.

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Hubble's tale of two exoplanets: Nature vs. nurture

This diagram compares Hubble Space Telescope observations of two "hot Jupiter"-class planets orbiting very closely to different sunlike stars. Astronomers measured how light from each parent star is filtered through each planet's atmosphere. HAT-P-38 b did have a water signature indicated by the absorption-feature peak in the spectrum. This is interpreted as indicating the upper atmosphere is free of clouds or hazes. WASP-67 b, has a flat spectrum that lacks any water-absorption feature, suggesting most of the planet's atmosphere is masked by high-altitude clouds.

Is it a case of nature versus nurture when it comes to two "cousin" exoplanets? In a unique experiment, scientists used NASA's Hubble Space Telescope to study two "hot Jupiter" exoplanets. Because these planets are virtually the same size and temperature, and orbit around nearly identical stars at the same distance, the team hypothesized that their atmospheres should be alike. What they found surprised them.

Lead researcher Giovanni Bruno of the Space Telescope Science Institute in Baltimore, Maryland, explained, "What we're seeing in looking at the two atmospheres is that they're not the same. One planet -- WASP-67 b -- is cloudier than the other -- HAT-P-38 b. We don't see what we're expecting, and we need to understand why we find this difference."

The team used Hubble's Wide Field Camera 3 to look at the planets' spectral fingerprints, which measure chemical composition. "The effect that clouds have on the spectral signature of water allows us to measure the amount of clouds in the atmosphere," Bruno said. "More clouds mean that the water feature is reduced." The teams found that for WASP-67 b there are more clouds at the altitudes probed by these measurements.

"This tells us that there had to be something in their past that is changing the way these planets look," said Bruno.

Today the planets whirl around their yellow dwarf stars once every 4.5 Earth days, tightly orbiting their stars closer than Mercury orbits our sun. But in the past, the planets probably migrated inward toward the star from the locations where they formed.

Perhaps one planet formed differently than the other, under a different set of circumstances. "You can say it's nature versus nurture," explains co-investigator Kevin Stevenson. "Right now, they appear to have the same physical properties. So, if their measured composition is defined by their current state, then it should be the same for both planets. But that's not the case. Instead, it looks like their formation histories could be playing an important role."

The clouds on these hot, Jupiter-like gas giants are nothing like those on Earth. Instead, they are probably alkali clouds, composed of molecules such as sodium sulfide and potassium chloride. The average temperature on each planet is more than 1,300 degrees Fahrenheit.

The exoplanets are tidally locked, with the same side always facing the parent star. This means they have a very hot day-side and a cooler night-side. Instead of sporting multiple cloud bands like Jupiter does, each probably has just one broad equatorial band that slowly moves the heat around from the day-side to the night-side.

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