Ocean Acidification, the Other CO2 Problem

Carbon dioxide (CO₂) is one of the most important “green-house” gases in the atmosphere affecting the radiative heat balance of the earth. As a direct result of the industrial and agricultural activities of humans over the past two centuries, atmospheric CO₂ concentrations have increased by about 100 ppm. The atmospheric concentration of CO₂ is now higher than experienced on Earth for at least the last 800,000 years, and is expected to continue to rise, leading to significant temperature increases in the atmosphere and oceans by the end of this century. The global oceans are the largest natural long-term reservoir for this excess heat and CO₂, absorbing approximately 85% of the heat and nearly 30% of the anthropogenic carbon released into the atmosphere since the beginning of the industrial era. Recent studies have demonstrated that both the temperature increases and the increased concentrations of CO₂ in the oceans are causing significant changes in marine ecosystems. Many marine organisms are already affected by these anthropogenic stresses, including impacts due to coral bleaching and ocean acidification.