Last year a working paper led by retired NASA scientist James Hansen incited controversy, and now, the final version of the research is stirring debate once again. In the paper, Hansen and other international scientists warn that the 2°C Paris limit could still cause irreparable damage to our planet, specifically through polar ice melts, superstorms, and rising sea levels that could demolish coastal cities. And those effects could be felt within decades, not centuries.

Climate change, global warming, James Hansen, ice melt, melting ice, superstorms, rising sea levels, sea level rise, carbon emissions

Concern over the effects of climate change on sea levels isn’t new. Yet scientists thought the shift would occur hundreds of years from now, and in his new paper, Hansen says sea levels could rise several feet in just 50 to 150 years.

Related: Antarctic shelf twice the size of Manhattan is about to break free

The research compared modern data against another period of climate change in Earth’s history, when the planet warmed naturally. Polar ice melted, leading to an estimated 20 to 30-foot rise in sea level. As polar ice is melting again today, the researchers believe this influx of fresh water into locales like Greenland and Antarctica will inhibit ocean currents that circulate heat, leading to a buildup that will melt ice sheets underneath the ocean’s surface. The drastically diverging temperatures throughout the ocean could then lead to superstorms.

Climate change, global warming, James Hansen, ice melt, melting ice, superstorms, rising sea levels, sea level rise, carbon emissions

So where’s the controversy? Some scientists worry Hansen’s activism stands in the way of his methods, and that he’s distorted findings for politics. Climate scientist Michael E. Mann of Pennsylvania State University said, “Some of the claims in the paper are indeed extraordinary. They conflict with the mainstream understanding of climate change to the point where the standard of proof is quite high.” However, Mann also said, “I think we ignore James Hansen at our peril.”

Nearly all scientists concur we haven’t taken enough action to lower emissions, and Hansen even went so far as to condemn the Paris talks as “worthless words.” His paper now calls for an immediate cutback in carbon emissions. In a video accompanying the research, Hansen said he doesn’t believe we’ve reached a point of no return, but we will if we don’t take action.

“I think the conclusion is clear. We are in a position of potentially causing irreparable harm to our children, grandchildren, and future generations. This is a tragic situation because it is unnecessary,” he said. “We could already be phasing out fossil fuel emissions if only we stopped allowing the fossil fuel industry to use the atmosphere as a free dumping ground for their waste. If we collected a gradually rising fee from fossil fuel companies, we could phase over to clean energies. If done right, it could spur the economy and create jobs.”

Via The New York Times

Images via NASA Goddard Space Flight Center on Flickr and Wikimedia Commons (1,2)