It’s almost impossible to open a newspaper or turn on the TV these days without seeing some story about global warming – it’s clearly the single biggest issue facing the world at the moment. But how do you go about conveying it in a photograph? That was the challenge set to ten of the UK’s top photographers by the National Trust for a exhibition that toured the UK during the summer of 2007.

The show, which was called ‘EXPOSED: Climate Change in Britain’s Backyard’, focused on the UK and brought together photographers from both the National Trust and Magnum Photos, including Joe Cornish, Simon Fraser, Paul Wakefield, Ian Berry, Mark Power and Chris Steele-Perkins.

Climate Challenge

As Joe Cornish puts it, ‘My first thought when I was asked to participate was “How am I going to photograph that?” Photographers photograph weather, they don’t photograph climate. It’s a difficult concept to convey so you do need good captions to give the photographs context.

After some thought, Joe headed to Snowdonia to repeat a shot he had taken of the top of Glyder Fawr – some 2500ft above sea level – during the same month (January) some years before.

The resulting ‘before and after’ shots form arguably the most shocking and dramatic examples of climatic change in the exhibition.

‘Not that long ago that Glyder Fawr would usually have been completely covered in snow at that time of year, but over the last four or five winters it’s been a struggle to find scenes like that. The permanent snowline in Snowdonia simply isn’t there any more,’ laments Joe.

Joe’s pictures are certainly impressive, but they hardly convey the difficulties and effort involved in their creation. To get the most dramatic landscape photographs of the ridge meant being there either at sunrise or sunset, but this entailed either climbing or descending in darkness, while carrying a heavy backpack – a dangerous undertaking.

‘Glyder Fawr is very steep in parts,’ explains Joe. ‘It isn’t just a brisk walk, it’s a scramble. You have to use your hands to clamber up and over rocks. Doing that while carrying a 50lb pack plus a tripod isn’t easy even in daylight. The only alternative is to camp out overnight, but adding the tent, sleeping bag and food would probably add an extra 30kg to the weight, which would be exhausting.

Meeting the Brief

Despite his initial concerns anout meeting such an abstract brief Joe and the other photographers were able to supply the exhibition with a series of images that clearly show the effects of climate change on the UK. Here’s a selection, and the thinking behind them.

Left: extraordinary amount of leaves in the canopy for the time of year, a sure sign of the complete Oak tree at Great Ayton, North Yorkshire. Joe took this around Christmas 2005. ‘There was an absence of frost through November.

Right: A rise in water temperature has caused algae to form a mat on the river, depleting the water of oxygen, leaving fish to suffocate. Photograph: Simon Fraser

Left: Blakeney, Norfolk. Living so close to the sea always poses the risk of flooding. Photograph: Ian Berry The intensity of rainfall has caused this house to flood six times in eight years. Photograph: Paul Wakefield