Living with the heat

In the long term, wildlife evolves to cope with both cooler and warmer climates. However, evolution is a harsh process. Many plants and animals cannot cope with the change and eventually become extinct. Meanwhile other organisms flourish because they adapt and develop features that enable them to survive. The result is a new mix of species to suit an altered world. This process enabled the mammals to take over when the dinosaurs became extinct 65 million years ago. Recent wildlife losses may be signaling that we are at the beginning of a similar process now.

OVERHEATED REEFS

As tropical oceans get warmer, coral reefs start to suffer. The corals that build reefs live in partnership with microscopic organisms that grow in their tissues and make food by photosynthesis. But if the water gets too warm, the corals expel the colorful microbes and turn white, like the coral in this picture. Corals can survive brief periods of this coral bleaching, but if the water stays too warm, they start running out of food and dying. Rising ocean temperatures will probably cause more bleaching events, threatening vulnerable corals with extinction.

ACIDIFIED OCEANS

When rain dissolves atmospheric carbon dioxide, it forms a weak carbonic acid. The same process is affecting the oceans as they absorb extra carbon dioxide from the air. It is not making the oceans acid, but it is making them less alkaline. The change could start to make life difficult for many marine animals such as corals, clams, and this lobster, which absorb alkaline minerals from the water to build their tough shells.

STARVING SEABIRDS

The oceanic food chain relies on the drifting microlife of the plankton which feeds the fish that are caught by hunters such as seabirds. Warmer oceans are changing the distribution of plankton, so fish move away from seabird nesting sites. In the north Atlantic, colonies of seabirds like these guillemots are failing because they cannot feed their young.

Snow leopard

Snow leopard

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