UN Report: Humans Are Making The Oceans Too Warm And Unable To Support Life
A new report from the UN’s Intergovernmental Panel on Climate Change (IPCC) has sobering news for all of us when it comes to the future of the oceans: We’re making them warmer and unable to support life.
“On Wednesday, the IPCC, convened by the UN to assess climate science, released a summary of the report on the oceans and frozen regions of the world, or cryosphere, for policymakers after more than 100 scientists reviewed thousands of scientific papers. The findings are immense and comprehensive, and seeing them all in one place is sobering.
“In all, ‘over the 21st century, the ocean is projected to transition to unprecedented conditions,’ the report warns. The ocean will be warmer, more acidic, hold less oxygen, be more greatly stratified (i.e. the top and bottom layers won’t mix as much). Ocean heat waves are growing more common, and it’s likely extreme El Niño and La Niña systems will form, leading to more extreme weather around the globe.”
And the oceans will only get warmer, due in large part to the thawing of frozen regions around the world that currently keep the water cool and habitable for marine life:
“The report makes it clear: the two largest ice sheets on Earth — the Greenland ice sheet, and the Antarctic ice sheet — are melting at an accelerating rate. ‘Mass loss from the Antarctic ice sheet over the period 2007 – 2016 tripled relative to 1997 –2006,’ the report finds. ‘For Greenland, mass loss doubled over the same period.'”
Sea ice also continues to decline each year. The National Snow and Ice Data Center recently reported that Arctic ice shrinkage occurred at a near-record rate this summer alone. That melting means that more water is exposed, which then absorbs more heat and then melts even more land ice. And that leads to a rise in the sea level.
The IPCC report also warns that as the oceans rise, their chemistry is also changing, and not for the better:
“As the ocean warms, it warms unevenly. The surface of the ocean becomes hotter than its depths, making the surface much less dense than the deep ocean. That leads to an increasing problem called stratification. The shallow water and the deeper water aren’t mixing as much. Nutrients in the deep don’t get back up to the surface as easily, and oxygen at the surface doesn’t get stored in deeper waters. It’s a situation that makes it harder for sea life to thrive in the oceans.”
As if that’s not bad enough, as ocean waters heat and lose oxygen, they also become more acidic. Acidic waters are bad for corals and shellfish because they decrease the level of carbonate, which such creatures need in order to build their shells. The long-term effects of that cannot possibly be overstated:
“’A decrease in global biomass of marine animal communities, their production, and fisheries catch potential, and a shift in species composition are projected over the 21st century,’ the summary report warns, with the greatest losses found in the tropical regions of the globe.
“In all, we’re looking at a future with less life in the oceans, and less ice at the poles. And that has huge impacts on the human communities who depend on ocean life to sustain their own.”
The impact of all this on humanity is dramatic and is already being felt:
“The report also tries to underscore how many people’s lives could be directly affected by changes in the oceans, and the cryosphere. It’s a huge portion of the world’s population. Around 680 million people live in low-lying coastal areas, which are most at risk for sea level rise. Around 65 million live on small, developing islands — which are at risk for sea level rise. Another 670 million live in the high mountain regions that are seeing snow and ice disappear as well, and with it, a key source of drinking water.”
There’s still time to act and reverse these trends. But will we?
Featured Image Via David Stanley/Flickr