The scientific community widely accepts that 2 degrees Celsius is the most the average global temperature can rise to avoid the most damaging effects of climate change. However, a new study published in the journal Science (the Guardian), has shown that even with the most modest temperature increase, a significant amount of sea level rise around the world’s coastal communities is still likely.
The paper outlined what happened to global sea levels the last time CO2 levels in the atmosphere were as high as they are today. About 3 million years ago, when the average temperature on earth was about 5 degrees F warmer. Sea levels were roughly 20 feet higher than their current levels, and the Arctic was a whopping 14 degrees F warmer than it currently is today.
According to Andrea Dutton, a geochemist at the university of Florida and one of the study’s authors, “Even if we meet that 2C target, in the past with those types of temperatures, we may be committing ourselves to this level of sea level rise in the long term… Once these ice sheets start to melt, the changes become irreversible.”
The study reached some startling conclusions. If the sea were to rise by 20 feet, the entire coastal U.S. would be reshaped. Louisiana would lose its boot shape, and San Francisco could become its own island.
Compared to preindustrial times, the sea is now about 8 inches higher than it used to be. Accelerated sea level rise could put established coastal cities at serious risk of water damage, and many fear that that acceleration has already begun.