Ocean warming is speeding up and sea levels are rising more quickly, warns a new report by the U. N. Intergovernmental Panel. The report also discusses a relatively new phenomenon in the oceans: marine (海洋的) heatwaves. "Before 2012 or 2013, nobody had thought about heat waves in the ocean, " says Andrew Pershing, chief scientist at the Gulf of Maine Research Institute in Portland. "Then in 2012 we had a huge event here. It was a real surprise." The abnormally hot water influenced animals that live off the coast of Maine and are important to the local fishing economy.
What's more, it quickly became clear that the state wasn't alone. "This kind of heat wave events has sprung up all over the ocean, " Pershing says. "We've actually had three major heat waves here - 2012, 2016 and 2018 and now we're looking at repeat heat waves in the northern Pacific; Australia has also had some repeat heat waves. So it's really becoming a part of the conversation in oceanography. "
That's a big deal for coastal communities whose economies depend on fish and other seafood. Heat waves drove a lot of changes in life off the coast of the Pacific Northwest, which in tum led to disastrous seasons for fishermen. Abnormally hot water supported rapid increase of algae (藻类) that polluted the Dungeness crab fishery on the West Coast, shutting it down for months. Meanwhile, the so-called hot water off the coast has been connected with drought (干旱) on land, which has led to a large number of fish runs, raised the risk of wildfires and resulted in water stress inland.
The report suggests some actions local, state and national leaders can take to slow ocean warming and rising, and to adapt (适应) to its influences. First，greenhouse gas emissions (排放) from burning fossil fuels are the main drive of these changes, and the global economy must go through a dramatic change to reduce these emissions.
"Even if we cut carbon emissions right now, we are still looking at 20 to 30 years of change, " Pershing explains." That means, whatever we do, we have to figure out how we are going to adapt to these changes. "
Some marine influences of climate change will unfold in the coming years no matter what. Speeding up sea level rise, for example, will threaten billions of people and present an existential threat to millions who live in coastal communities and count on fishing.
