Academics and campaigners are calling on all parties to set out clear plans to evacuate cities and move to a fossil fuel-free economy, as they condemn politicians of all persuasions for virtually ignoring climate change during their election campaigning.

In a letter published in the Independent, University of Cambridge Professor Peter Wadhams and nine other leading climate change experts warn that the world is headed for an ‘unavoidable nightmare’ that will “pose grave problems for all aspects of society in the short-term and certainly well before the end of the next parliament”.

Particular problems are likely to result from the rising sea levels, ocean acidification and melting Arctic ice and permafrost associated with climate change, the letter warns.

“The future of all nations is irrevocably and immediately threatened. Yet we see little to no discussion of any of this by any of the main political parties during this general election. We therefore request for the benefit of the electorate as a matter of urgency that all parties specifically set down clearly what policies they propose,” said the letter, also signed by Professor John Whitelegg of the University of York and University of Southampton genocide researcher Dr Mark Levene.

Climate change Show all 7 1 /7 Climate change Climate change Coastal systems and low-lying areas Flood damaged streets in Queens, New York where the historic boardwalk was washed away due to Hurricane Sandy in 2012. The report predicts that by the end of the century “hundreds of millions of people will be affected by coastal flooding and displaced due to land loss” Getty Climate change Food security Widespread drought devastated a corn crop on a farm near Bruceville, Indiana in 2012. The report forecasts that climate change will reduce median yields by up to 2 per cent per decade for the rest of the century AFP/Getty Climate change The global economy The Evening Standard headline board showing the words 'Black Friday Shares Crash' in London in October 2008 in London. The report warns a global mean temperature increase of 2.5C above pre-industrial levels may lead to global aggregate economic losses of between 0.2 and 2.0 per cent Getty Climate change Human health A child suffering from malnutrition and diarrhoea is seen at the Banadir hospital in the Somalian capital of Mogadishu in 2009. Climate change will lead to increases in ill-health in many regions, with examples including an increased likelihood of under-nutrition. Getty Climate change Human security A Muslim migrant holds his son as they are detained at the Immigration Police Office on the Thai-Malaysian border in March 2014. The report states that climate change over the 21st century will have a significant impact on forms of migration that compromise human security EPA Climate change Freshwater resources A villager walks through a parched paddy in Tianlin county, China in 2012. The report finds that climate change will “reduce renewable surface water and groundwater resources significantly in most dry subtropical regions" Getty Climate change Unique landscapes Machair, a grassy coastal habitat found only in north-west Scotland and the west coast of Ireland, is one of the several elements of the UK’s “cultural heritage” that is at risk from climate change Getty

The letter also calls on parties to set out their policies for protecting critical infrastructure such as nuclear power stations from flooding, for building infrastructure in flood risk areas and for international co-operation to tackle climate change.

“I think it’s a disgrace that climate change is seeing so little attention and it’s a sad indictment of the political system in the UK and internationally,” Prof Wadhams told The Independent.

“Emissions in the UK and EU have come down a little bit but only because we have outsourced our manufacturing to China and India where emissions have gone up in leaps and bounds,” he added.

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