NEW YORK (AP) Due to climate change, the worlds oceans are getting warmer, rising higher, losing oxygen and becoming more acidic at an ever-faster pace and melting even more ice and snow, a grim international science assessment concludes.
But thats nothing compared to what Wednesdays special United Nations-affiliated oceans and ice report says is coming if global warming doesnt slow down: three feet of sea rise by the end of the century, many fewer fish, weakening ocean currents, even less snow and ice, stronger and wetter hurricanes and nastier El Nino weather systems.
The oceans and the icy parts of the world are in big trouble and that means were all in big trouble too, said one of the reports lead authors, Michael Oppenheimer, professor of geosciences and international affairs at Princeton University. The changes are accelerating.
These changes will not just hurt the 71% of the world covered by the oceans or the 10% covered in ice and snow, but it will harm people, plants, animals, food, societies, infrastructure and the global economy, according to the special report by the Intergovernmental Panel on Climate Change.
The oceans absorb more than 90% of the excess heat from carbon pollution in the air, as well as much of the carbon dioxide itself. The seas warm more slowly than the air but trap the heat longer with bigger side effects and the report links these waters with Earths snow and ice, called the cryosphere, because their futures are interconnected.
The worlds 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.
The report found:
Seas are now rising at one-seventh of an inch a year, which is 2.5 times faster than the rate from 1900 to 1990.
The worlds oceans have already lost 1% to 3% of the oxygen in their upper levels since 1970 and will lose more as warming continues.
From 2006 to 2015, the ice melting from Greenland, Antarctica and the worlds mountain glaciers has accelerated and is now losing 720 billion tons (653 billion metric tons) of ice a year.
Arctic June snow cover has shrunk more than half since 1967, down nearly 1 million square miles.
Arctic sea ice in September, the annual minimum, is down almost 13% per decade since 1979. This years low, reported Monday, tied for the second-lowest on record. If carbon pollution continues unabated, by the end of the century there will be a 10% to 35% chance each year that sea ice will disappear in the Arctic in September.
Marine animals are likely to decrease 15%, and catches by fisheries in general are expected to decline 21% to 24% by the end of century because of climate change.
And for the first time, the international team of scientists is projecting that some island nations are likely to become uninhabitable due to climate-related ocean and cryosphere change.
Climate change is already irreversible, French climate scientist Valérie Masson-Delmotte, a report lead author, said in a Wednesday news conference in Monaco. Due to the heat uptake in the ocean, we cant go back.
But many of the worst-case projections in the report can still be avoided depending on how the world handles the emissions of heat-trapping gases, the reports authors said.
The IPCC increased its projected end-of-century sea level rise in the worst-case scenario by nearly four inches from its 2013 projections because of the increased recent melting of ice sheets in Greenland and Antarctica.
