The World Resources Institute recently issued a report on the health and future prospects for the world’s coral reefs. Entitled “Reefs at Risk Revisited,” the study tracks global warming impacts on coral reefs through 2050. The verdict? Not too hot for Earth’s reefs. Simply put, under business as usual fossil fuel emissions, it doesn’t seem likely there will be many, if any, reefs remaining by 2100.
The study shows warming will be highly damaging to coral reef systems by or before the 2030 and that such damage will become catastrophic by the 2050s. The above map only tracks damage due to coral bleaching, not damage due to reef stress from human activity, or damage due to ocean acidification.
Ocean acidification is caused by increasing levels of Carbon Dioxide (CO2) in the atmosphere. And since the dawn of the industrial revolution, CO2 levels have been creeping upward. Due to human emissions, world CO2 concentrations are now rising at the rate of 2.2 ppm each year. And a good amount of the CO2 that doesn’t end up in the air ends, instead, in the ocean. Scientists show that some corals and coral reef systems are under stress from acidification with current world CO2 levels at 393 ppm. Most studies show that coral reefs would be wiped out by the time concentrations reach 600-650 ppm. Under business as usual CO2 emissions, this level will likely be reached by the latter half of the 21rst century.
The WRI shows bleaching due to human-caused warming at critical levels during the same period.
The combined impacts of heat stress, human activity, and ocean acidification creates dangerous stresses to reef systems now. Over the coming decades, increasing damage from these sources will place the continued existence of coral reefs in doubt.
WRI also provides a compelling video investigating current stresses to coral reefs around the world: