Climate Change and the World’s Coral Reefs
It is estimated that 70 per cent of the Earth’s surface area is made up of oceans that, in-turn, provide habitat for 75 per cent of all known species on earth. The ocean also plays an important role in regulating global temperature and serves as the primary producer of the world’s oxygen. Coral reefs, which comprise only about 0.5 per cent of the ocean floor, are the “rainforest of the sea” providing food to all levels of the food chain.
(Transcript of Lawrence Gunther’s bi-weekly 12-minute segment on Live from Studio 5 broadcast over AMI TV and Audio across Canada)
Q. Welcome back Lawrence, what does Trump’s withdrawal from the Paris Accord mean to the rest of the world?
A. The U.S. is the second largest emitter of CO2; acknowledged as the leading contributor to climate change. Ocean currents will be altered, sea levels will rise, and more frequent and severe storms will impact coastal communities. The ocean is already about 30% more acidic now than it was in the past 250 years, due largely to having absorbed about 1/3 of the CO2 produced by humans over this same period.
A. Further, as climate change continues to increase ocean temperatures, the migration of certain marine organisms will migrate northward, while those less temperature tolerant species die off. Ocean acidification caused by increased CO2 levels that lower the pH of seawater will reduce the abundance of phytoplankton, the bedrock of the food chain, and will decrease calcification in certain marine animals like corals and shellfish, causing their skeletons to become weaker and their growth impaired.
Q. Is this the Whitehouse denying climate change, or is this another example of balancing economic interests with environmental destruction?
A. Not sure, but according to the U.S. National Atmospheric and Oceanic Administration, a key agency of the U.S. government, scientific evidence now clearly indicates that the Earth’s atmosphere and ocean are warming primarily due to greenhouse gases derived from human activities, and that Climate change is the greatest global threat to coral reef ecosystems. The International Society for Reef Studies predicts that 90 percent of coral reefs worldwide will be at risk of destruction by 2050.
Q. How is climate change linked to the bleaching of reefs?
A. Bleaching occurs when corals respond to the stress of warmer temperatures by expelling the colorful algae that live within them. Some coral are able to recover, but too often the coral dies, and the entire ecosystem for which it forms the base, virtually disappears. It’s the consumption of these algaes by fish that is responsible for creating the white beaches found along much of the equator. That white beach sand is actually coral that was ground up and pooped out by fish.
Q. What does the destruction of reefs mean to marine life?
A. Reefs serve as the nursery for many ocean fish, or as the foundation for the food chain upon which they depend. There’s not a lot of cover where sea-life can escape their being consumed, which is why so many fish species choose to either dwell in reefs, or use reefs to provide shelter to their offspring.
Q. Are we fighting a losing battle?
A. Quite possibly climate change might have already passed the point of no return. Upwards of 80 per cent of the reefs surrounding Caribbean islands have already died, and miles of the Barrier Reefs surrounding Australia have suffered bleaching. If we continue to produce carbon dioxide at the current rate, the ocean’s pH level will lower to the point that the world’s remaining coral reefs will be lost. The solution to climate change is also the solution to coral reef recovery.