Warming oceans around the Great Barrier Reef may have caused back-to-back bleaching events that killed off as much as half of the World Heritage site. According to the Great Barrier Reef Marine Park Authority, 30 percent of the coral system, an ecosystem spanning more than 1,400 miles off the northern coast of Australia, was wiped out by warming waters in 2016; another 20 percent died off this year.
The successive bleaching events are troubling given that even the fastest growing corals need a decade or more to recover.
"It's widely understood that, with two degrees of warming, we will lose all reefs globally," Australian Senator Larissa Waters told news.com.au. The dire state of the Great Barrier Reef underscores the importance of the Paris Agreement, which aims to keep global warming below two degrees Celsius.
Leaders around the globe are eagerly awaiting President Donald Trump's decision on whether or not the United States—the second-biggest greenhouse gas emitter in the world after China—will remain in the agreement. He is expected to make an official announcement after this week's G7 summit in Italy.