The effects of humans, and our contribution to climate change have a significant impact on coral reefs in a variety of ways.
Ocean Warming
Greenhouse gas emissions and the warming of the oceans is the most obvious impact which results in coral bleaching. To date, 70% of global coral reefs have experienced these destructive bleaching events. Corals thrive in water between 23-31˚C much of the world’s coral currently exists in water right at the upper limit of this temperature range and in shallow water most susceptible to increases. An increase of just one degree can trigger a bleaching event here in the Gulf of Thailand.
Acidification
Increased levels of CO2 in our atmosphere also dissolve into the ocean lowering the overall pH. This results in what we call ocean acidification which results in corals building weaker structures and becoming more susceptible to damage from storms.
Dissolved Oxygen Content
A final significant factor is the results of runoff from human coastal settlement. Dense coastal population settlements often result in hypoxic “dead zones” where there is not enough dissolved oxygen to support life. Species such as clownfish are highly at risk as they require high levels of dissolved O2. If species that exist in the coral reef ecosystem are lost it can become unbalanced and ultimately result in its destruction.