NASA data shows July 22, 2024 was Earth's hottest day on record

July 22, 2024, was the hottest day on record, according to a NASA analysis of global daily temperature data. July 21 and 23 of this year also exceeded the previous daily record, set in July 2023. These record-breaking temperatures are part of a long-term warming trend driven by human activities, primarily the emission of greenhouse gases. As part of its mission to expand our understanding of Earth, NASA collects critical long-term observations of our changing planet.

"In a year that has been the hottest on record to date, these past two weeks have been particularly brutal," said NASA Administrator Bill Nelson.

"Through our over two dozen Earth-observing satellites and over 60 years of data, NASA is providing critical analyses of how our planet is changing and how local communities can prepare, adapt, and stay safe. We are proud to be part of the Biden-Harris Administration efforts to protect communities from extreme heat."

This preliminary finding comes from data analyses from Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) and Goddard Earth Observing System Forward Processing (GEOS-FP) systems, which combine millions of global observations from instruments on land, sea, air, and satellites using atmospheric models.

GEOS-FP provides rapid, near-real time weather data, while the MERRA-2 climate reanalysis takes longer but ensures the use of best quality observations.

These models are run by the Global Modeling and Assimilation Office (GMAO) at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Daily global average temperature values from MERRA-2 for the years 1980-2022 are shown in white, values for the year 2023 are shown in pink, and values from 2024 through June are shown in red.

Daily global temperature values from July 1 to 23, 2024, from GEOS-FP are shown in purple.

The results agree with an independent analysis from the European Union's Copernicus Earth Observation Programme.

While the analyses have small differences, they show broad agreement in the change in temperature over time and hottest days.

Read more at Science Daily

On a warming planet, these Arctic geese rapidly found (and shared) a new migratory route

As the planet warms, animals that breed in the Arctic are at particular risk. But a new study reported in Current Biology on March 1 offers some encouraging news: in an apparent reaction to pressures along their former migratory route, a population of Arctic geese has rapidly adjusted, forming a new migration route and breeding location almost 1,000 kilometers from their original stomping grounds.

What's more, it appears the new route has caught on with other geese and even birds of other species via cultural transmission (social learning). As such, the new population already has grown to as many as 4,000 individuals.

"It is extremely fascinating to witness such rapid evolution of new breeding grounds and migratory route by a bird species that is regarded as being very traditional in its behavior and site use," said Jesper Madsen of Aarhus University in Denmark. "It gives some hope for 'ecological rescue' at times of very radical environmental changes due to climate change and, more broadly, global change."

"We observe a new distinct population of birds in the making in real time," he added. "This is very rare to observe. The speed of the development is astonishing."

Madsen's team has been studying Norway's Svalbard population of pink-footed geese for more than 35 years. They've kept tabs on their population size and demographic variables, using a systematic marking and resighting program. About 20 years ago, they started getting reports of geese turning up on migration in Sweden and Finland, which were confirmed as members of the Svalbard population.

To learn more, Madsen went to Oulu, Finland, in the spring of 2018 and 2019 with his goose-catching team from Denmark as well as Dutch and Finnish partners. Their hope was to catch and tag some pink-footed geese with GPS tags. They wanted to know where these geese were going, and they got an unexpected answer.

"It was a real surprise to see that half of the marked individuals in Oulu migrated northeast to Novaya Zemlya in north Russia," Madsen says. "From the tagging information we could not only follow their new path but also got indications that females were breeding there. This site is around 1,000 kilometers east of the Svalbard breeding grounds.

"It was also cool to observe that geese from the traditional flyway have turned up on the new route and seemed to have switched. Hence, social learning and following individuals from the new route has been an important phenomenon, which also explains how this development could be so fast."

With their new report, they've now documented an abrupt formation of a new migration route and population for the Arctic geese over the course of 10 to 15 years. The population has grown over time due to successful breeding and high survival rates combined with continued immigration of geese from the old route to the new one.

Their ability to live in Novaya Zemlya has apparently been aided by warming in the area, they say. While the new population is not genetically or demographically isolated yet, they note that it already now qualifies as a separate population.

The new route does have some disadvantages, Madsen says. For instance, it's longer. But they suspect the benefits of the new route and grounds outweigh any downsides. The findings in geese show the importance of social learning on a changing planet, Madsen notes, especially in social animals including birds but perhaps also hoofed ungulates, wolves, and whales.

"At this time, when climate change and other human activities threaten many species, not least the Arctic ones, social learning can be a behavior that can provide advantages to avoid some negative impacts, at least in the short term," Madsen says.

The researchers say they hope one day to observe the geese in their new breeding grounds in Russia. For now, they'll keep an eye on the future development of the new population using GPS-tracking devices and remote sensing of the new environment.

Read more at Science Daily

Feedback loops make climate action even more urgent, scientists say

An international collaboration led by Oregon State University scientists has identified 27 global warming accelerators known as amplifying feedback loops, including some that the researchers say may not be fully accounted for in climate models.

They note that the findings, published today in the journal One Earth, add urgency to the need to respond to the climate crisis and provide a roadmap for policymakers aiming to avert the most severe consequences of a warming planet.

In climate science, amplifying feedback loops are situations where a climate-caused alteration can trigger a process that causes even more warming, which in turn intensifies the alteration. An example would be warming in the Arctic, leading to melting sea ice, which results in further warming because sea water absorbs rather than reflects solar radiation.

OSU College of Forestry postdoctoral scholar Christopher Wolf and distinguished professor William Ripple led the study, which in all looked at 41 climate change feedbacks.

"Many of the feedback loops we examined significantly increase warming because of their connection to greenhouse gas emissions," Wolf said. "To the best of our knowledge, this is the most extensive list available of climate feedback loops, and not all of them are fully considered in climate models. What's urgently needed is more research and modeling and an accelerated cutback of emissions."

The paper makes two calls to action for "immediate and massive" emissions reductions:
 

• Minimize short-term warming given that "climate disasters" in the form of wildfires, coastal flooding, permafrost thaw, intense storms and other extreme weather are already occurring.
• Mitigate the possible major threats looming from climate tipping points that are drawing ever-closer due to the prevalence of the many amplifying feedback loops. A tipping point is a threshold after which a change in a component of the climate system becomes self-perpetuating.

"Transformative, socially just changes in global energy and transportation, short-lived air pollution, food production, nature preservation and the international economy, together with population policies based on education and equality, are needed to meet these challenges in both the short and long term," Ripple said. "It's too late to fully prevent the pain of climate change, but if we take meaningful steps soon while prioritizing human basic needs and social justice, it could still be possible to limit the harm."

Ripple, Wolf and co-authors from the University of Exeter, the Potsdam Institute for Climate Impact Research, the Woodwell Climate Research Center and Terrestrial Ecosystems Research Associates considered both biological and physical feedbacks. Biological feedbacks include forest dieback, soil carbon loss and wildfire; physical feedbacks involve changes such as reduced snow cover, increased Antarctic rainfall and shrinking arctic sea ice.

Even comparatively modest warming is expected to heighten the likelihood that the Earth will cross various tipping points, the researchers say, causing big changes in the planet's climate system and potentially strengthening the amplifying feedbacks.

"Climate models may be underestimating the acceleration in global temperature change because they aren't fully considering this large and related set of amplifying feedback loops," Wolf said. "The accuracy of climate models is crucial as they help guide mitigation efforts by telling policymakers about the expected effects of human-caused greenhouse gas emissions. While recent climate models do a much better job of incorporating diverse feedback loops, more progress is needed."

Emissions have risen substantially over the last century, the researchers note, despite several decades of warnings that they should be significantly curbed. The scientists say interactions among feedback loops could cause a permanent shift away from the Earth's current climate state to one that threatens the survival of many humans and other life forms.

"In the worst case, if amplifying feedbacks are strong enough, the result is likely tragic climate change that's moved beyond anything humans can control," Ripple said. "We need a rapid transition toward integrated Earth system science because the climate can only be fully understood by considering the functioning and state of all Earth systems together. This will require large-scale collaboration, and the result would provide better information for policymakers."

In addition to the 27 amplifying climate feedbacks the scientists studied were seven that are characterized as dampening -- they act to stabilize the climate system. An example is carbon dioxide fertilization, where rising concentrations of atmospheric CO2 lead to increasing carbon uptake by vegetation.

The effects of the remaining seven feedbacks, including increased atmospheric dust and reduced ocean stability, are not yet known.

Read more at Science Daily

NASA says 2022 fifth warmest year on record, warming trend continues

Earth's average surface temperature in 2022 tied with 2015 as the fifth warmest on record, according to an analysis by NASA. Continuing the planet's long-term warming trend, global temperatures in 2022 were 1.6 degrees Fahrenheit (0.89 degrees Celsius) above the average for NASA's baseline period (1951-1980), scientists from NASA's Goddard Institute for Space Studies (GISS) in New York reported.

"This warming trend is alarming," said NASA Administrator Bill Nelson. "Our warming climate is already making a mark: Forest fires are intensifying; hurricanes are getting stronger; droughts are wreaking havoc and sea levels are rising. NASA is deepening our commitment to do our part in addressing climate change. Our Earth System Observatory will provide state-of-the-art data to support our climate modeling, analysis and predictions to help humanity confront our planet's changing climate."

The past nine years have been the warmest years since modern recordkeeping began in 1880. This means Earth in 2022 was about 2 degrees Fahrenheit (or about 1.11 degrees Celsius) warmer than the late 19th century average.

"The reason for the warming trend is that human activities continue to pump enormous amounts of greenhouse gases into the atmosphere, and the long-term planetary impacts will also continue," said Gavin Schmidt, director of GISS, NASA's leading center for climate modeling.

Human-driven greenhouse gas emissions have rebounded following a short-lived dip in 2020 due to the COVID-19 pandemic. Recently, NASA scientists, as well as international scientists, determined carbon dioxide emissions were the highest on record in 2022. NASA also identified some super-emitters of methane -- another powerful greenhouse gas -- using the Earth Surface Mineral Dust Source Investigation instrument that launched to the International Space Station last year.

The Arctic region continues to experience the strongest warming trends -- close to four times the global average -- according to GISS research presented at the 2022 annual meeting of the American Geophysical Union, as well as a separate study.

Communities around the world are experiencing impacts scientists see as connected to the warming atmosphere and ocean. Climate change has intensified rainfall and tropical storms, deepened the severity of droughts, and increased the impact of storm surges. Last year brought torrential monsoon rains that devastated Pakistan and a persistent megadrought in the U.S. Southwest. In September, Hurricane Ian became one of the strongest and costliest hurricanes to strike the continental U.S.

Tracking Our Changing Planet

NASA's global temperature analysis is drawn from data collected by weather stations and Antarctic research stations, as well as instruments mounted on ships and ocean buoys. NASA scientists analyze these measurements to account for uncertainties in the data and to maintain consistent methods for calculating global average surface temperature differences for every year. These ground-based measurements of surface temperature are consistent with satellite data collected since 2002 by the Atmospheric Infrared Sounder on NASA's Aqua satellite and with other estimates.

NASA uses the period from 1951-1980 as a baseline to understand how global temperatures change over time. That baseline includes climate patterns such as La Niña and El Niño, as well as unusually hot or cold years due to other factors, ensuring it encompasses natural variations in Earth's temperature.

Many factors can affect the average temperature in any given year. For example, 2022 was one of the warmest on record despite a third consecutive year of La Niña conditions in the tropical Pacific Ocean. NASA scientists estimate that La Niña's cooling influence may have lowered global temperatures slightly (about 0.11 degrees Fahrenheit or 0.06 degrees Celsius) from what the average would have been under more typical ocean conditions.

A separate, independent analysis by the National Oceanic and Atmospheric Administration (NOAA) concluded that the global surface temperature for 2022 was the sixth highest since 1880. NOAA scientists use much of the same raw temperature data in their analysis and have a different baseline period (1901-2000) and methodology. Although rankings for specific years can differ slightly between the records, they are in broad agreement and both reflect ongoing long-term warming.

Read more at Science Daily

A prehistoric climate feedback loop

Against the backdrop of a rapidly warming planet, the need to better understand the nature and long-term impact of positive climatic feedback loops -- processes that accelerate the effects of warming -- becomes critically important.

One way to assess the role and impact of climatic feedback processes is to use modeling studies to look into the likely future based on what we know now. Climate projection models, for instance, are the tools behind the 1.5° C global warming threshold adopted by the Intergovernmental Panel on Climate Change.

Alternatively, you can look into the past to see what happened at a time when the Earth was up to 1-1.5°C warmer than today. That is what UC Santa Barbara's Syee Weldeab did in a paper published in the Proceedings of the National Academy of Sciences. The professor of paleoclimatology found feedback processes that have concerning implications for our modern, ongoing warming.

To get a paleoclimate perspective on global warming, Weldeab and his colleagues went back some 128,000 to 125,000 years ago to the peak Eemian warm episode. Oceans were up to 1-1.5°C warmer than during the Holocene (our current geological epoch). The authors examined marine sediment from the tropical Atlantic and found exceptionally strong warming of the intermediate water column during a brief interval within the peak Eemian warm episode.

"Remarkably, a substantially diminished Greenland Ice Sheet was capable of producing enough meltwater to perturb the density-driven circulation of the Atlantic Ocean," Weldeab said. "This contributed significantly to the large warming of the intermediate waters we reconstructed."

Typically, warm, salty water travels north from the tropics along the surface of the ocean and cools as it reaches northern mid and high latitudes. At this point, the now colder, denser water drops to the deep sea and travels back down toward the tropics. This interplay of density differences results in the currents that we're familiar with today.

"What happens when you put a large amount of fresh water into the North Atlantic is basically it disturbs ocean circulation and reduces the advection of cold water into the intermediate depth of the tropical Atlantic, and as a result warms the waters at this depth," he said.

While previous studies have discussed the disruption that meltwater caused to currents and temperatures at intermediate depths, the new paper reveals that this warming was "larger than previously thought."

"We show a hitherto undocumented and remarkably large warming of water at intermediate depths, exhibiting a temperature increase of 6.7°C from the average background value," Weldeab said.

This exceptionally strong warming has serious consequences. As the warm water impinges on marine sediment that contains abundant methane hydrates -- a mixture of frozen water and methane. These deposits are not far below the surface of the seafloor.

Weldeab explained that at high pressure and low temperatures, the introduction of unusually warm water heats the seafloor sediment, and the ice-encapsulated gases begin to dissolve, releasing methane. Weldeab and colleagues used carbon isotopes (13C/12C) in the shells of microorganisms to uncover the fingerprint of methane release and methane oxidation across the water column.

"This is one of several amplifying climatic feedback processes where a warming climate caused accelerated ice sheet melting," he said. "The meltwater weakened the ocean circulation and, as a consequence, the waters at intermediate depth warmed significantly, leading to destabilization of shallow subsurface methane hydrates and release of methane, a potent greenhouse gas."

It is not known for sure whether this feedback cycle will play out in the current round of global warming, though anthropogenic activity has created a higher rate of warming than the one that occurred in the Eemian period. These findings, according to the researchers, "document and connects a sequence of climatic events and climatic feedback processes associated with and triggered by the penultimate peak climate warming that can serve as a paleo-analogue for modern ongoing warming."

Read more at Science Daily

A warming planet could mess with our sleep -- and make us more vulnerable to infectious disease

It's a scene that will be familiar for many after yet another scorching summer: You're lying awake during a warm night, bedsheets kicked aside, an overmatched ceiling fan providing little respite as you struggle to get a good night's sleep.

But a warming planet doesn't just mean more people may find it harder to get quality sleep. There is also evidence suggesting that sleep disturbance could make it harder for the body to fend off infection, according to a new research paper from Dr. Michael Irwin, a professor of psychiatry and biobehavorial sciences at UCLA.

Irwin, who has extensively studied how sleep regulates the immune system, said while there are few studies on how ambient, or surrounding air, temperature affects sleep, they indicate that warmer temperatures contribute to sleep disturbance. Studies have also shown that poor sleep is associated with heightened risk of infectious disease and could make some vaccination less effective, Irwin writes in a research review published in the peer-reviewed journal Temperature last week.

Given research showing a potential link between poor sleep and reduced immune response, Irwin said this raises timely questions about whether climate change results in heightened infectious disease risk amid the ongoing COVID-19 pandemic, a monkeypox outbreak and the reemergence of the poliovirus in New York and London.

"No one has previously put together this notion that the ongoing climate crisis is contributing to sleep disturbance and that it's possibly contributing to the altered risk of infectious disease we're seeing," said Irwin, the director of the Cousins Center for Psychoneuroimmunology at the Jane and Terry Semel Institute for Neuroscience and Human Behavior at UCLA.

Irwin said the issue also raises important implications about disparities, since low-income communities and communities of color face heightened risk from heat and have less access to air conditioning.

What the research shows

Irwin's paper reviews how poor sleep affects the immune system and could make people more vulnerable to infectious disease threats. Among the research he cites:

- There's a strong association between sleep and thermoregulation, or how humans maintain a steady core internal temperature. Experimental studies have shown that reducing air temperatures to a range in which humans can maintain a normal body temperature without expending excess energy improves sleep quality, while increases in air temperature result in increased wakefulness. Survey data of 765,000 people in the United States also found increases in nighttime temperatures amplified self-reported nights of insufficient sleep, with the largest effects during the summer and among lower-income and elderly people.

- It's thought that sleep helps prepare the body's response to possible injury or infection that could occur the following day. When sleep is disrupted, that contributes to increases in inflammation and dampens the body's ability to fight off infections. That means there may be heightened risk among older adults and patients with inflammatory disorders, like cardiovascular disease and some types of depression, who have higher prevalence of insomnia.

- Some small experimental studies in humans indicate that poor sleep could also result in poorer vaccine response. In one study, for instance, people who had four straight nights of partial sleep deprivation before receiving a trivalent influenza vaccine had a 50% reduction in antibody titers compared to those with normal sleep. Other studies that tested the effects of sleep disruption after influenza or hepatitis vaccination suggest that short sleep duration, at least in healthy adults, is likely associated with a reduced adaptive immunologic response and possibly clinical protection.

- Sleep duration is also associated with infectious disease risk outcomes. Basic research has shown that longer sleep leads to decreases in bacterial load and improved survival in a variety of infectious disease models. Self-reported surveys have also shown an association between shorter sleep and higher infection risk.

- While there's abundant evidence that sleep disturbance and depressive symptoms have greatly increased during the COVID-19 pandemic, there's little known about how poor sleep may be affecting risk of COVID-19 infection and outcomes. However, a recent study of over 46,000 patients indicated that a significant sleep disturbance was associated with an over 2-fold increase in the mortality risk for patients who had COVID-19, while no similar association was found in those who did not.

Irwin said that future research on this topic should evaluate how altering ambient temperatures affects sleep and, as a result, immune function. He said there should also be a focus on how rising ambient temperatures may be affecting diverse and disadvantaged communities.

Read more at Science Daily