Changing Climate in Hawaii Affects Coral Reefs
Oceans absorb over 80% of the heat added to the climate system, and about 30% of the CO2 released by humans. When CO2 dissolves in seawater, carbonic acid is created making more acidic oceans. A warmer and more acidic ocean will not be hospitable for coral reefs. Coral organisms are very sensitive to heat stress and expel their colorful symbiotic algae (bleaching) when the water warms. Corals also form their hard skeletons from calcium, an ability compromised as the oceans continue to become more acidic.
Few coral bleaching events were recorded before 1980. Since then many events, including a mass bleaching event in the 1990’s that killed 16% of the planet’s coral, are on record. As oceans continue to warm, bleaching will become more frequent and severe.
By mid-century, temperature and CO2 levels are predicted to increase beyond levels experienced for at least a half-million years. The dual threats of ocean acidification and warming lead some scientists to believe that most of the world’s coral reefs will disappear by the end of the century.
This Week’s MYTH Buster: “Climate science seems like guesswork.”
The specific effects of climate change are uncertain (eg., how much the temperature will increase). Despite this, it would be far riskier to do nothing. We must move forward with the best tested and most rigourous science we have today.
I Will Make a Difference: by eating locally grown food (reduces food transport).
More on the NPS and climate change