09/25/2019 Science 0

Due to climate change, the world’s 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 that’s nothing compared to what Wednesday’s special United Nations-affiliated oceans and ice report says is coming if global warming doesn’t 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 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.”Even if warming is limited to just another couple of tenths of a degree, the world’s warm water coral reefs will go extinct in some places and be dramatically different in others, the report said.“We are already seeing the demise of the warm water coral reefs,” Portner said. “That is one of the strongest warning signals that we have available.”The report gives projections based on different scenarios for emissions of heat-trapping carbon dioxide. One is a world that dramatically decreases carbon pollution — and the worst case is where little has been done. We are closer to the worst-case situation, scientists said.Outside scientists praised the work but were disturbed by it.“It is alarming to read such a thorough cataloging of all of the serious changes in the planet that we’re driving,” said Texas A&M University climate scientist Andrew Dessler, who wasn’t part of the report. “What’s particularly disturbing as a scientist is that virtually all of these changes were predicted years or decades ago.”The report’s authors emphasized that it doesn’t doom Earth to this gloomy outlook.“We indicate we have a choice. Whether we go into a grim future depends on the decisions that are being made,” Portner said. “We have a better future ahead of us once we make the right choice.”“These far-reaching consequences can only be brought under control by acute emissions reductions,” Portner said.
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