If You’re 97% Certain, You’re Certain.
97% is a formidable number. If 97% of doctors told you surgery would save your life, you’d have surgery. If 97% of nutritionists said a food was linked to cancer, you’d never touch it again. So when 97% of climate scientists agree that humans are warming the planet, it’s time to pay attention.
Scientists have studied whether or not climate scientists agree about climate change. And lo and behold, they do. 97% of them anyway.
The National Academies of Science of China, Russia, India, Brazil, Canada, France, Germany, Italy, Japan, and the United Kingdom agree with those scientists. So do eighteen different American scientific academies.
Among the impacts scientists agree on most are rising sea levels. There are two causes. Warmer temperatures are melting mountain glaciers and polar ice caps, while parts of West Antarctica and Greenland are thawing at a disturbing pace. As the ice continues to melt, seas rise. The oceans also absorb heat. As warmer water expands, it also causes sea level rise.
Sea levels have already risen about eight inches since pre-industrial times, and rose faster in the 20th century than ever before. This has increased flooding in coastal cities and magnified the impact of storm surges. The surge from Super Storm Sandy caused a 14 foot flood, sweeping cars away in Lower Manhattan.
Several recent studies predict sea levels could rise up to six feet by the end of this century. As many as 13 million Americans in coastal regions could be vulnerable, including New York City, Boston, Los Angeles and San Francisco. In Miami, six feet would mean two million people would be displaced.
Globally, the figures are potentially even worse, with London, Shanghai, Mumbai, Sydney and other major cities threatened.
 John Cook, et al, “Quantifying the consensus on anthropogenic global warming in the scientific literature,” Environmental Research Letters. May 15, 2013.
 NASA, “Scientific Consensus”
 National Geographic, “Sea Level Rise.”
 Robert E. Kopp et al, “Temperature-driven global sea-level variability in the Common Era,” Proceedings of the National Academy of Sciences. January 4, 2016.
 National Center for Atmospheric Research, “Evaluating the effects of future sea level rise and storm surges along US coastlines,” 2012.
 New York City, “Sandy and its Impacts,” 2012.
 Don Melvin and Ray Sanchez, “Ice melt could make seas rise 6 feet by 2100, study says,” CNN. April 2, 2016.
 Will Dunham, “Sea level rise projected to displace 13 million in US by 2100,” Reuters. March 14, 2016.
 Justin Worland and David Johnson, “See how your city be may affected by rising sea levels,” TIME. March 14, 2016.
 Matthias Mengel et al, “Future sea level rise constrained by observations and long-term commitment,” Proceedings of the National Academy of Sciences. January 19, 2016.