The United Nations (UN) General Assembly is ongoing this week and the UN's Intergovernmental Panel on Climate Change (IPCC) has released a new report on the current and future status of climate change.
The new IPCC report doesn't necessarily tell us anything we didn't already know in broad strokes, but it does warn that a feedback loop is developing in the oceans where heat is being absorbed and will contribute to significantly worse storm systems in the future.
The report also warns that cities will be submerged and islands will disappear as sea level rises by at least three feet by the end of the century.
The report projects that sea levels could rise by one meter (3.3 feet) by 2100 — ten times the rate in the 20th century — if emissions keep climbing. The rise could exceed five meters by 2300.
In the Himalayas, glaciers feeding ten rivers, including the Ganges and Yangtze, could shrink dramatically if emissions do not fall, hitting water supplies across a swathe of Asia.
Thawing permafrost in places like Alaska and Siberia could release vast quantities of greenhouse gases, potentially unleashing feedback loops driving faster warming.
Following a subsequent report published last month on land use and farming, the IPCC Special Report on the Oceans and Cryosphere — or ‘frozen world’ — was the final piece in a scientific jigsaw revealing the global sweep of climate impacts.
It's worth noting that the IPCC's reports are not strictly scientific reports; they're a collaboration between scientists and governments.
In other words, these are actually conservative estimates and we should look at the possibility that seas will rise by over three feet as the best-case scenario, not the worst.
It's understandable why these reports are usually based on conservative estimates. The public is far more forgiving to underestimations than it is to cries that the sky is falling if it doesn't fall.
From the Associated Press:
“The oceans and the icy parts of the world are in big trouble, and that means we’re all in big trouble, too,” said one of the report’s lead authors, Michael Oppenheimer, professor of geosciences and international affairs at Princeton University. “The changes are accelerating.” [...]
“The world’s oceans and cryosphere have been taking the heat for climate change for decades. The consequences for nature and humanity are sweeping and severe,” said Ko Barrett, vice chair of the IPCC and a deputy assistant administrator for research at the U.S. National Oceanic and Atmospheric Administration.