Reefs at Risk Revisited reveals a new reality about coral reefs and the increasing stresses they are under.
This piece originally appeared as the foreword to Reefs at Risk Revisited. 
As anyone who has spent time around the ocean knows—whether diving, conducting research, or fishing—coral reefs are among the world’s greatest sources of beauty and wonder. Home to over 4,000 species of fish and 800 types of coral, reefs offer an amazing panorama of underwater life.
Coral reefs supply a wide range of important benefits to communities around the world. From the fisherman in Indonesia or Tanzania who relies on local fish to feed his family, to the scientist in Panama who investigates the medicinal potential of reef related compounds, reefs provide jobs, livelihoods, food, shelter, and protection for coastal communities and the shorelines along which they live.
Unfortunately, reefs today are facing multiple threats from many directions. 2010 was one of the warmest years on record, causing widespread damage to coral reefs. Warmer oceans lead to coral bleaching , which is becoming increasingly frequent around the globe—leaving reefs, fish, and the communities who depend on these resources at great risk. No one yet knows what the long-term impacts of this bleaching will be. But, if the ocean’s waters keep warming, the outlook is grim.
Against this backdrop, the World Resources Institute has produced Reefs at Risk Revisited , a groundbreaking new analysis of threats to the world’s coral reefs. This report builds on WRI’s seminal 1998 report, Reefs at Risk , which served as a call to action for policymakers, scientists, nongovernmental organizations, and industry to confront one of the most pressing, though poorly understood, environmental issues. That report played a critical role in raising awareness and driving action, inspiring countless regional projects, stimulating greater funding, and providing motivation for new policies to protect marine areas and mitigate risks.
However, much has changed since 1998—including an increase in the world’s population, and with it greater consumption, trade, and tourism. Rising economies in the developing world have led to more industrialization, more agricultural development, more commerce, and more and more greenhouse gas emissions. All of these factors have contributed to the need to update and refine the earlier report.
The warming planet is quickly becoming the chief threat to the health of coral reefs around the world.
The latest report builds on the original Reefs at Risk in two important ways. First, the map-based assessment uses the latest global data and satellite imagery, drawing on a reef map that is 64 times more detailed than in the 1998 report. The second major new component is our greater understanding of the effects of climate change on coral reefs. As harmful as overfishing, coastal development, and other local threats are to reefs, the warming planet is quickly becoming the chief threat to the health of coral reefs around the world. Every day, we dump 90 million tons of carbon pollution into the thin shell of atmosphere surrounding our planet—roughly one-third of it goes into the ocean, increasing ocean acidification .
[img_assist|nid=12036|title=Threat to Coral Reefs from Ocean Acidification in the Present, 2030, and 2050|desc=|link=node|align=left|width=240|height=268]
Coral reefs are harbingers of change. Like the proverbial “canary in the coal mine,” the degradation of coral reefs is a clear sign that our dangerous overreliance on fossil fuels is already changing Earth’s climate. Coral reefs are currently experiencing higher ocean temperatures and acidity than at any other time in at least the last 400,000 years. If we continue down this path, all coral reefs will likely be threatened by mid-century, with 75 percent facing high to critical threats levels.
Reefs at Risk Revisited  reveals a new reality about coral reefs and the increasing stresses they are under. It should serve as a wake-up call for policymakers and citizens around the world. By nature, coral reefs have proven to be resilient and can bounce back from the effects of a particular threat. But, if we fail to address the multiple threats they face, we will likely see these precious ecosystems unravel, and with them the numerous benefits that people around the globe derive from these ecological wonders. We simply cannot afford to let that happen.
Hon. Al Gore
Former Vice President of the United States
Al Gore is a member of WRI's Board of Directors .