Climate change, we're told, poses the single gravest threat to the survival of our species. And if the experience of our ancient relatives the Neanderthals is anything to go by, we should take note of the warnings.
Recent research has suggested that climate change may have been the killer blow that finished off our closest evolutionary cousins.
For about 400,000 years, the Neanderthals dominated Europe, hunting big game such as mammoth and bison.
These hardy cavemen and cavewomen survived one Ice Age after another. But eventually, their luck ran out. For reasons which remain unclear, Neanderthal populations went into terminal decline.