Repealing EPA’s climate findings is bad news for public health
Nothing has changed in the science of climate change. There is overwhelming evidence to suggest that greenhouse gases are the main cause of global warming.
Tens of millions more people may be threatened by climate change than previously thought, as previous studies used incorrect information about water levels along the world’s coastlines, a new study says.
The new study, published March 4 in the British peer-reviewed journal Nature, found that more than 90% of existing sea level surveys use a reference sea level that is lower than the actual sea level along the coast. That means already dire predictions about sea level rise may be underestimating the risk.
“Our calculations show that measured coastal sea levels in many places around the world are higher than often assumed in coastal impact studies,” study lead author Catalina Seeger from the University of Padua in Italy said in a statement. “Our findings require that the methodologies underlying all existing coastal hazards research be re-evaluated and, in most cases, updated,” she added.
What is sea level rise?
Sea level rise, one of the clearest signs of human-induced global warming, is caused by the warming and expansion of ocean waters, as well as the melting of mountain glaciers, ice sheets, and the vast ice sheets of Greenland and Antarctica.
Sea levels have risen nearly 8 inches around the world since 1880, but unlike water in a bathtub, it doesn’t rise evenly.
For example, over the past 100 years, ocean currents and natural subsidence of the land have caused water levels to rise by about a foot or more in some U.S. cities.
Scientists said global warming will be the main cause of sea level rise. The biggest uncertainty is how quickly West Antarctica’s giant ice sheet will melt.
What causes global warming?
Anthropogenic climate change is caused by the burning of fossil fuels such as gas, coal, and oil, which release greenhouse gases such as carbon dioxide (CO2) and methane into the atmosphere. This extra CO2 increases atmospheric and ocean temperatures to levels that cannot be explained by natural causes.
Why is sea level rise important?
Rising sea levels are increasing the risk of coastal flooding, putting tens of millions of people in the United States and hundreds of millions of people around the world at risk. Approximately 40% of the world’s population lives within 100 km of a coast. As climate change impacts the world, sea level rise is a pressing issue for many coastal communities.
Specifically, in the new study, the authors found that, compared to previous estimates, if sea levels rose by 1 meter, there would be up to a 37% increase in land beneath sea level, potentially impacting between 77 million and 132 million people worldwide.
What does new research show?
Most sea level surveys to date do not reflect reality because they lack direct sea level measurements or incorrectly combine sea level and land elevation data, according to a new study.
“We seem to be dealing with an interdisciplinary blind spot between ocean-level science on the one hand and continent-based coastal hazards influencing science on the other,” said study co-author Philip Minderhoud, a professor of hydrogeology at Wageningen University & Research in the Netherlands.
One easy way to understand this is that many studies assume an ocean surface without waves or currents, but the reality at the water’s edge is an ocean that is constantly being shaken up by wind, tides, ocean currents, temperature changes, El Niño events, and more, Minderhoud and Seeger told The Associated Press.
“We hope this approach will become a new standard for more accurately assessing future coastal impacts,” the authors conclude in their study.
Which regions are most at risk?
This underestimation of sea level rise was particularly notable in the Global South, particularly in Southeast Asia and the Pacific region.
Underestimation was also observed in Latin America, the West Coast of North America, the Caribbean, Africa, the Middle East, and the Indo-Pacific.
What do others think about this study?
“I think the new sea level rise article in Nature is important,” said Michael Mann of the University of Pennsylvania, who was not involved in the study. “The community as a whole appears to be missing the important distinctions they are drawing, which means we may be (significantly) underestimating potential sea level rise in many important regions.
“There’s still quite a bit of uncertainty because of complications with changes in ocean currents and things like that, but this study seems important to me,” Mann told USA TODAY.
