The world’s marine ecosystems risk being severely damaged by ocean acidification unless there are dramatic cuts in CO2 emissions, warn scientists.
The researchers warn that ocean acidification, which they refer to as “the other CO2 problem”, could make most regions of the ocean inhospitable to coral reefs by 2050, if atmospheric CO2 levels continue to increase.
This does indeed sound alarming, until you consider that corals became common in the oceans during the Ordovician Era – nearly 500 million years ago – when atmospheric CO2 levels were about 10X greater than they are today. (One might also note in the graph below that there was an ice age during the late Ordovician and early Silurian with CO2 levels 10X higher than current levels, and the correlation between CO2 and temperature is essentially nil throughout the Phanerozoic.)
Perhaps corals are not so tough as they used to be? In 1954, the US detonated the world’s largest nuclear weapon at Bikini Island in the South Pacific. The bomb was equivalent to 30 billion pounds of TNT, vapourised three islands, and raised water temperatures to 55,000 degrees. Yet half a century of rising CO2 later, the corals at Bikini are thriving. Another drop in pH of 0.075 will likely have less impact on the corals than a thermonuclear blast. The corals might even survive a rise in ocean temperatures of half a degree, since they flourished at times when the earth’s temperature was 10C higher than the present.