But is there still hope for nature? Coral reefs are responding alarmingly to climate change, but some people are showing great ingenuity in response to this and other ecological problems.
Stunning reefs turning into ‘white wastelands’
Bleached: Experts fear this summer could be the worst ever for Great Barrier Reef coral (above). Glossary
Algae - A simple plant that grows in or on water.
vulnerable - at risk of being harmed
Spawn - To cause something new, or many new things, to grow or start suddenly.
Larvae - Insects in the next stage of development after they have emerged from eggs. A caterpillar is a larva.