From India’s deadly heat waves and the unprecedented drought in California, to unusual polar bear behavior in the Arctic and increased volcanic activity in Iceland, climate change is already wreaking havoc on our biosphere. Though no individual aberration can be conclusively credited to climate change, “global weirding” is exactly what scientists expect to occur as temperatures continue to rise. To prepare for this brave new world, researchers at Oregon State University conducted a study to determine how past global temperature increases have affected sea levels. In a report published in the journal Science, the researchers conclude that even a small increase in temperature of 1 to 2 degrees Celsius, or 1.8 to 3.6 Fahrenheit, may result in sea level rises of up to 20 feet.
The implications of the report are particularly dire due to warming already locked in by greenhouse gas emissions thus far. The report focuses on the effect that melting ice sheets might have on global sea level rise. “Modern atmospheric carbon dioxide levels are today equivalent to those about 3 million years ago, when sea level was at least 6 meters higher because the ice sheets were greatly reduced,” says Anders Carlson, OSU glacial geologist and paleoclimatologist and co-author of the report. “It takes time for the warming to whittle down the ice sheets, but it doesn’t take forever. There is evidence that we are likely seeing that transformation begin to take place now.”
Although the IPCC has previously identified a temperature rise of 2 degrees Celsius as the threshold beyond which catastrophic climate change is certain, the researchers conclude this change may already be unavoidable. “We are already committed to a certain amount of sea level rise,” says Peter Clark, OSU paleoclimatologist and co-author of the report. “The ominous aspect to this is that CO2 levels are continuing to rise, so we are entering uncharted territory. What is not as certain is the time frame, which is less well-constrained. We could be talking many centuries to a few millennia to see the full impact.”