From the Arctic to Antarctica, the reality of climate change is becoming ever more apparent as sea ice melts, glaciers retreat and droughts, floods and storms become more frequent.
These changes are not only impacting on people but also on wildlife globally. Polar bears are finding it harder to hunt on the receding ice and Peary caribous are suffering due to a lack of winter fodder. The golden toad of Costa Rica is believed to be the first species to have become extinct due to climate change, as rainfall patterns and humidity levels have changed in the cloud forests.
And this is only the first stage of much larger changes to come - unless we implement ambitious programmes to cut our emissions from fossil fuel combustion.
Unprecedented rate of change
While average temperatures have risen at a rate of around 0.6° C over the last century, the Arctic and Antarctic have seen much higher increases. A 6° C warming over the last decade in the Arctic has been accompanied by 40% decrease in the thickness of the Arctic sea ice. These changes threaten species that depend on the ice for hunting and rearing their young such as polar bears and walruses.
Elsewhere, rising sea temperatures are posing a new threat to already over-fished stocks of cod and have resulted in a severe bleaching of large areas of coral reefs.
While the climate has changed in the past, change is now happening at a much faster rate, making it difficult for all but the most mobile species, such as birds, to move and adapt. Add habitat destruction and urban sprawl, intensive agriculture and other developments and many plants, birds and mammals will simply have nowhere to go.
A recent report by WWF on climate change and wildlife* has highlighted the impacts climate change may have. The accelerating rates of warming we can expect in coming decades are likely to put large numbers of species at risk.
In particular in the higher latitudes of the northern hemisphere, where the warming will be greatest, it is questionable whether they will find suitable habitats elsewhere. Plants may need to move 10 times faster than they did at the end of the last ice age.
The worst affected countries are likely to be Canada and Russia, which could lose more than half their current habitats, with an associated species loss of up to 20% in some areas. For example, as the Arctic tundra is replaced by forest, millions of geese, ducks and wading birds are likely to lose their summer breeding habitat.
High migration rates will particularly threaten rare, isolated or slow-moving species. The winners in the climate change race will be weeds, pests and generalists that can move, reproduce or adapt fast.
While rabbits are unlikely to be threatened, species at risk include the rare Gelada baboon in Ethiopia, the mountain pygmy possum of Australia, the monarch butterfly at its Mexican wintering grounds, and the spoon-billed sandpiper at its breeding sites in Russia's arctic far east.
In the UK, the impacts of climate change on wildlife initially look positive. Swallows now arrive much earlier in the spring and leave later in the autumn and Little Egrets breed on the South Coast. The rare Dartford warbler is at record levels.
However, the irony is that further climate change may eventually destroy the heathland habitats on which this and other rare species depend. There are very few opportunities to re-create lowland heath away from its current stronghold in southern England.
Most at threat are mountain habitats. For example, in the Cairngorms in Scotland, dotterels, ptarmigans and mountain hares are likely to disappear. Elsewhere, rare, isolated species such as the Arctic char (found in Cumbrian lakes) and the Snowdon lily may not survive. The prime birding sites (mudflats and saltmarshes) in East Anglia are under threat from sea-level rise.
But something can still be done
Some species will be able to adapt and move northwards but we need to make sure that they have places to go to and are not stopped by roads or fields of wheat. A good network of protected areas is crucial but we have to accept that we cannot preserve what we have now in perpetuity.
Some change is inevitable; the challenge now is to reduce emissions to avoid the worst case scenario of vast species and habitat loss.
* Malcolm, J and Markham, A (2000). Global warming and terrestrial biodiversity decline: A report for WWF