New studies suggest that coral bleaching is being caused by the use of a common chemical in sunscreens, oxybenzone, rather than it being an effect of global warming. Huffpo has an article based on the Tel Aviv study that looked at oxybenzone levels in the water in Hawaii and the US Virgin Islands and made the connection to coral reef bleaching. Coral reefs are profoundly important to life in the ocean (which is why we donate 10% to stop ocean acidification- a result of climate change. Now we have another cause to support).
The good news is that you can make a difference! There are many sunscreen options that use physical barrier methods rather than chemical ones to protect you from the sun. Look for the ingredients zinc oxide and titanium oxide next time you purchase a sunscreen or use the EWG list. And use it as a great excuse to wear a fabulous hat.