A new study published in the Journal Science is predicting big rises in sea level of up to 20 feet as ice melts in the Arctic and Antarctic over the coming centuries or perhaps millennia.
Climate change could lead to seas rising 20 feet
ByMICHAEL CASEY
Rising sea levels have been mostly measured in inches in the past decades, but scientists said they could increase more than 20 feet in the future as global warming continues to melt ice sheets in Greenland and Antarctica.
The dire projections are based on a look back at the climate record, with scientists finding that increases of 20 feet have happened at least twice over the past 3 million years when temperatures were very similar to what they are today.
If similar increases were seen across the globe, that could put tens of millions of people living in coastal communities from New York to Miami to Bangkok at risk of storm surges and increased flooding. Even NASA is fearing its launch pads could be threatened by climate change.
Many of these coastal communities are already seeing increased flooding - and that is just from global sea levels rising around 8 inches since 1880. Records also indicate the rate of sea level rise has intensified since the 1990s.
"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," he said. "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."
Peter Clark, an Oregon State paleoclimatologist and another co-author of the study, said that because current carbon dioxide levels are as high as they were 3 million years ago, "we are already committed to a certain amount of sea level rise."
"The ominous aspect to this is that CO2 levels are continuing to rise, so we are entering uncharted territory," Clark said. "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 of melting ice sheets."
"If anything, we may be looking at worst scenarios because carbon dioxide levels are much higher so our inference is that ice sheets are out of equilibrium with the present climate so that they are now catching up to all this warming that has occurred in the atmosphere and the ocean," Andrea Dutton, a University of Florida geochemist and lead author on the study, said.
We humans have modified our planet's climate to the extent that we've moved from a stable sea level to a rising sea level that is now increasing, and will continue to rise for centuries to come. Until the ice in the Arctic and Antarctic comes back into warmer equilibrium with our warmer climate.
Also see: Greenland is Experiencing a Sudden and Rapid Melt Season Onset
This is a sobering video about the coming rises in sea level.