This post was updated on December 3, 2021 For an ecosystem that covers 70 percent of the planet, oceans get no respect . They feed us, provide most of the oxygen we breathe and protect us from the worst effects of global warming. Were it not for the oceans, climate change would have already made Earth uninhabitable. How? The oceans have absorbed more than 90 percent of the global warming created by humans since the 1970s. Had that heat gone into the atmosphere, global average temperatures would have jumped by almost 56 degrees Celsius (100 degrees Fahrenheit). But as vast as the seas are, there is a limit to how much heat they can absorb — and they are beginning to reach it. Conservation News examines some of the ways that climate change affects life in the oceans — and what that means for humanity. 1. Higher temperatures are bad for fish — and for us Persistently rising temperatures are having cascading effects on marine life.…