Global warming is increasing ocean temperatures to a point that is killing coral reefs around the planet. Why should we care about coral reefs? Because they are vital ecosystems that nurture an estimated quarter of ocean species at some point during their life cycles. They support fish that provide protein for millions of people and they protect coasts from storms. The world's coral reefs have an estimated economic value of $2.7 trillion annually. The destruction of these reefs is yet another disaster caused by global warming.