The ocean is in the midst of a radical, manmade change. It can seem kind of crazy that one of the most immense properties on Earth—the ocean washes over 71 percent of the planet—could be completely transformed by a swarm of comparatively tiny, fleshy mammals. But humans are indeed remaking the ocean, in almost every conceivable way. The ocean we know today—that billions swim, fish, float, and surf in—that vast planetary body of water will be of an entirely different character by the end of the century.
“There is only one global ocean,” as NOAA likes to say. While it’s changing in different ways and to different degrees in different places, it’s a single, huge, interconnected system. Trash dumped in Oregon can end up in the great Pacific Garbage Patch. Pollution from China drifts overseas into North America. All of our carbon emissions end up partially absorbed by oceans everywhere—your actions in Sheboygan, USA have affected, in some minute way, the future of the seas in Bangladesh. That’s the thing about climate change.