Stressed out: Mapping the human footprint on coastal areas globally

A global mapping project led by University of Queensland researchers has revealed the major stressors placed upon global coastlines by human activity.

The team quantified and mapped the presence and extent of major land-based and marine stressors, finding that 97 per cent of coastal areas globally had at least one major stressor present.

Professor Salit Kark from UQ's School of Biological Sciences said the research team were surprised at the sheer extent and far-reaching impact revealed by the footprint map created.

"There is hardly anywhere on the planet, outside of the polar and arctic regions, that does not show some form of human pressure on their coastline," Professor Kark said.

"In essence, we have influenced the majority of coastal areas globally.

"We therefore should aim to map and understand our impacts, and also leave some untouched coastlines."

UQ PhD candidate Hannah Allan said the research outlined the spatial extent and magnitude of 10 major land-based stressors and 10 major marine stressors that occur across coastlines globally.

"The threats human activity pose to coastal ecosystems and biodiversity come from both the land and sea, sometimes arriving far from human activity," Ms Allan said.

"Therefore, coastal conservation must incorporate land-sea connections.

"Human population size, tourism, and roads were some of the biggest contributors to the terrestrial component of Australia's coastal human footprint.

"As for marine stressors, increasing sea surface temperatures, nutrient pollution, and shipping were found to be major drivers of human pressure on Australian coastlines."

Professor Noam Levin said a map of this kind, which assembles both terrestrial and marine stressors and presents the coastal human footprint globally, has rarely been attempted.

"This research offers valuable insights that could help decision-makers and managers identify where to mitigate particular impacts," Prof. Levin said.

"For example, the database underlying the human footprint can show specific areas with high oil and gas operations, such as in Western Australia.

"This can help develop preparedness procedures for the very realistic chance of environmental disasters that impact coastal areas, such as oil spills.

"An added benefit of our new global map is that it helps prioritise these decisions based on how widespread the potential pressures of our human footprint in certain areas of the world might be.

"Coastal areas, where 90 per cent of Australians live, were not immune to these stressors.

"For Australia, the highest human footprint was found in the coastal cities, in the order of Melbourne, Sydney, Perth, Adelaide, and Brisbane.

"We also mapped 160 areas on the planet with the most pristine coastal areas, including several in Australia.

"Of those, nearly 40 per cent were totally unprotected -- opening an opportunity to identify coastal areas for further conservation actions.

"A key finding was that light pollution is increasing, with more white LEDs being used, placing great strain on areas of high importance for biodiversity, disrupting the natural patterns of wildlife."

Moving forward, researchers are looking to fine-tune the mapping process, looking more specifically at Australia's coastlines.

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U.S. coastline to see up to a foot of sea level rise by 2050

The United States is expected to experience as much sea level rise by the year 2050 as it witnessed in the previous hundred years. That's according to a NOAA-led report updating sea level rise decision-support information for the U.S. released in partnership with half a dozen other federal agencies.

The Sea Level Rise Technical Report provides the most up-to-date sea level rise projections for all U.S. states and territories by decade for the next 100 years and beyond, based on a combination of tide gauge and satellite observations and all the model ensembles from the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). The report projects sea levels along the coastline will rise an additional 10-12 inches by 2050 with specific amounts varying regionally, mainly due to land height changes.

The report updates the federal government's 2017 sea level rise projections, and provides additional information on tide, wind, and storm-driven extreme water levels affecting current and future coastal flood risk. A suite of federal tools are using this data, including the NOAA Sea Level Rise Viewer, which are critical to the Administration's commitment to tackle the climate crisis by making actionable climate data accessible to those who need it.

"For businesses along the coast, knowing what to expect and how to plan for the future is critical," said U.S. Secretary of Commerce Gina M. Raimondo. "These updated projections will help businesses, and the communities they support, understand risks and make smart investments in the years ahead."

"This new data on sea rise is the latest reconfirmation that our climate crisis -- as the President has said -- is blinking 'code red,'" said Gina McCarthy, National Climate Advisor. "We must redouble our efforts to cut the greenhouse gases that cause climate change while, at the same time, help our coastal communities become more resilient in the face of rising seas."

"This is a global wake-up call and gives Americans the information needed to act now to best position ourselves for the future," said Rick Spinrad, Ph.D., NOAA Administrator. "As we build a Climate Ready Nation, these updated data can inform coastal communities and others about current and future vulnerabilities in the face of climate change and help them make smart decisions to keep people and property safe over the long run."

The report also finds that the sea level rise expected by 2050 will create a profound increase in the frequency of coastal flooding, even in the absence of storms or heavy rainfall.

"By 2050, moderate flooding ⁠ -- which is typically disruptive and damaging by today's weather, sea level and infrastructure standards ⁠ -- is expected to occur more than 10 times as often as it does today," said Nicole LeBoeuf, NOAA National Ocean Service Director. "These numbers mean a change from a single event every 2-5 years to multiple events each year, in some places."

"This report supports previous studies and confirms what we have long known: Sea levels are continuing to rise at an alarming rate, endangering communities around the world. Science is indisputable and urgent action is required to mitigate a climate crisis that is well underway," said Bill Nelson, NASA Administrator. "NASA is steadfast in our commitment to protecting our home planet by expanding our monitoring capabilities and continuing to ensure our climate data is not only accessible but understandable."

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