If you've ever seen a documentary about the Great Barrier Reef, you know that coral reefs are basically the underwater version of New York City or Tokyo. They are vibrant, bustling hubs of activity that support a quarter of all marine life on Earth, even though they cover less than 1% of the ocean floor. But if you dive on those same reefs today, you might find something that looks more like a ghost town. Because of global warming, these massive ocean cities are experiencing something called "coral bleaching," and if we don't fix the political gridlock preventing climate action, we are going to lose them forever.

The Science of Bleaching

Corals are fascinating creatures. They have a symbiotic relationship with tiny, colorful algae that live inside their tissues. These algae, called zooxanthellae, use photosynthesis to provide the coral with up to 90% of its food and give the reef its beautiful colors. However, corals are extremely sensitive to temperature changes. When the ocean absorbs the massive amounts of excess heat trapped by our greenhouse gas emissions, the water gets too warm. This heat stresses the corals, causing them to panic and forcefully expel the algae living inside them. Without the algae, the coral turns completely bone white—which is why it's called "bleaching"—and begins to starve to death.

The Consequences of a Dead Reef

When a reef dies, the entire ecosystem collapses. The fish that rely on the reef for shelter and food disappear. But the consequences aren't just limited to the ocean. Hundreds of millions of people around the world rely on coral reefs for their livelihoods and their daily food source. Furthermore, healthy reefs act as massive underwater sea walls that protect coastlines from massive waves and tropical storms. As the reefs crumble and die, the coastal communities behind them are left completely unprotected against the increasingly severe hurricanes caused by climate change. The death of the reefs is an economic and humanitarian disaster waiting to happen.

Political Inaction and Ocean Conservation

Despite the severity of this crisis, ocean conservation is rarely a top political priority. Politicians are perfectly willing to argue about jobs and the economy, but they rarely mention the collapse of the oceans. The problem is that the oceans have no voice in Congress or Parliament, and the marine ecosystems don't pay lobbyist fees. The only way to save the reefs is to rapidly and drastically reduce global carbon emissions to cool the planet. Local efforts, like banning certain sunscreens or stopping overfishing, are helpful, but they are like putting a band-aid on a gaping wound. Until our political leaders treat the oceans as a vital part of our global life support system, the great underwater cities will continue to fade into white.