To Save Corals, Stop Burning Fossil Fuels
New research shows climate change is causing widespread degradation of coral reefs
Tropical corals around the world are dying. Scientists used to assume that degradation had multiple synergistic causes, from global warming down to pollution, overfishing, and other localized impacts. But new research that I co-authored shows that global stressors are overwhelming the effects of more localized forces. Not surprisingly, it zeroes in on a single culprit: our over-reliance on fossil fuels.
The implications of this study are alarming, but they also clarify what we must do, adding to a growing body of scientific research calling for a rapid transition to renewable energy sources. Simply put, corals and the diverse ecosystem they support are unlikely to recover if we don’t address climate change now.
Coral reefs are among the most important and diverse ecosystems in the ocean. They supply food for humans and myriad coastal and oceanic food webs, not to mention supporting entire local economies through tourism and protecting coastal areas from storms and erosion. Carbon emissions that are steadily warming the planet and are being absorbed by the ocean are slowly killing corals by warming and acidifying the water they live in.
This isn’t news. We already knew global warming harms coral reefs; since last year we’ve seen that reality on vivid display during massive coral bleaching episodes from the Hawaiian Islands to the Great Barrier Reef. But some in the scientific community believed we could buy ourselves some time with better management of local factors, such as creating marine protected areas that minimized the impacts of fishing and addressing water-quality problems in coastal areas.
That hope was based on the belief that isolated coral reefs are in better shape, having more live corals and less seaweed than those near urban areas, which are presumably more profoundly affected by human activities. But when we analyzed a database of more than 1,700 coral reef surveys from around the world, we found that conventional wisdom didn’t hold up to scrutiny.
Healthy coral reefs have more living coral and less seaweed, factors that we’d expect to find in areas untouched by people. But the data showed no correlation between isolation and healthy coral reefs, leaving only one possible cause for their steady global degradation: ocean warming and acidification, both caused by global carbon emissions.
Don’t get me wrong: Local stewardship of coral reefs is extremely important. Recent research has shown bright spots across the world’s reefs where good governance is driving fish communities to thrive unexpectedly. In fact, biodiversity of reef fish makes these ecosystems more resilient and able to adapt to changing ocean conditions, so we should control overfishing. Coastal runoff and local pollution sources can also undermine the health of coral reef communities.
There’s much we should do to restore the health of oceans, which have been hurt by generations of abuse and neglect. We need to protect endangered species, from the chambered nautilus to sharks and whales; reduce the amount of plastic pollution building up in the oceans; prevent the devastating oil spills that go along with offshore drilling; regulate wasteful fishing practices that kill mountains of unintended bycatch; and generally become better stewards of our seas.
But when it comes to saving our coral reefs for the future, there’s one important thing we must do immediately: end our unhealthy addiction to fossil fuels.
