rising sea temperatures are an inevitable byproduct of increasing levels of co2 in the atmosphere. these warmer waters threaten the survival of coral reefs, some of earth’s most productive and diverse ecosystems. corals can only survive in specific water conditions and are very sensitive to react to changes in temperatures. a minimal rise or fall in water temperatures by 2-3ºC disrupts the symbiotic relationship between a coral and the algae living within its tissues. when the water temperature leaves the range suitable for coral and algae to survive in, the algae is expelled, which causes the coral to turn completely white. this phenomenon is referred to as bleaching.

most corals can revive themselves after short-term periods of bleaching, but the bleaching process limits their growth, makes them more vulnerable to the elements, and may cause death. in 1998, 16% of the world’s coral reefs perished due to bleaching. studies in asia’s oceans show that levels of coral bleaching in 2010 are at the peak since 1998 levels.

throughout evolution, corals have been able to adapt to environmental changes, but the rapidity and extremity of current changes present a challenge to the adaptability of coral reefs. it is likely that in the next 50 years, co2 levels in the atmosphere will double. some believe that even the most optimistic speculations of future co2 concentrations spell out a disastrous future for coral reefs.