I’m a polar bear, get me out of here!
Emma Summerscales explains how ‘hyper-warming’ could change the North and South Poles into tropical rainforest
Photo: khairilfz (Flickr)
Latest word on the climate block is that the poles could turn into tropical rainforest by the year 2300 if we carry on combusting. This may sound far-fetched considering the north and south poles have been iced over for an impressive 35 million years; we certainly couldn’t imagine them any other way. However, owing to a process known as ‘hyper-warming’, it is possible.
Climate scientists have been busy creating future scenarios, which show us what the Earth might look like in the future depending on how well we treat it today. The most pessimistic yet fascinating version has the Arctic flourishing with flora and fauna, as it was way back in the Cretaceous period. Back then it was 10°C hotter than it is today, and plants that we see in South America now were growing in the most northerly part of the globe.
Hyper-warming is where the planet gets hotter because a larger area of the globe is covered by water, and sea water absorbs more of the sun’s heat than land does. This is a phenomenon last seen in the Cambrian period, when water temperatures reached a staggering 40°C. Temperatures could be pushed up by a further 3°C if the Arctic does indeed become colonised by rainforest because of the albedo effect; foliage reflects less light away than ice does.
The planet could get even hotter than this as the scenarios do not include the effects of positive feedbacks such as the release of methane from sources such as permafrost. Hydroxyl-free radicals break down methane in the upper atmosphere which means it normally hangs around for about ten years, but should a huge store suddenly become liberated, the system could become saturated. The net result would be methane being present for much longer periods, increasing the effect that it has on the earth as a potent greenhouse gas. There is also evidence that, in the Eocene period when temperatures were last in this sort of ball park, carbon stores in the oceans failed.
Carbon would normally be found in the carcasses of marine creatures, but higher temperatures allow bacteria at the surface of the ocean to thrive. They metabolise all the carbon so that it doesn’t have chance to sink to the depths and get stored away.
We may be many years away from Arctic rainforests, but the idea is nonetheless intriguing. It puts into perspective the fact that we are only seeing the Earth for a fraction of its lifetime, like a snapshot. In a few hundred years with the influences of the human population it could be completely changed, or exactly the same.
