The conclusions of the fifth assessment report of the Intergovernmental panel on climate change (IPCC) – the world’s foremost authority on climate-change – delivered late last month were seering and stark: “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.”

The findings are bleak, but not unexpected; climate change has been scientifically beyond doubt for a long time. Yet despite virtually all climatologists and researchers confirming this with vast swathes of supporting evidence, there are still loud voices doing their utmost to persuade us that the issue is still somehow open for debate.

In the US roughly half of media reports on climate change have doubted its existence. Publications like the Daily Mail, the Wall Street Journal and numerous Murdoch press give editorial support to these views.



Cynical and insulting

Such contrarian writers and broadcasters paint themselves as climate “sceptics”, but this is a calculated misnomer. Scepticism is an essential part of scientific endeavour. It demands all claims are treated as unproven until evidence and experience either confirm or falsify them. Denialism, by contrast, is the stubborn and persistent refusal to acknowledge what the evidence shows beyond all reasonable doubt.

Evidence for climate change is overwhelming, confirmed by measurement, theory and experiment. Self-proclaimed climate “sceptics” are nothing of the sort; they are rank denialists, deliberately refusing to accept the incontrovertible evidence that their position is untenable.

The tired old tactics of the denialists are nothing more than empty parlour tricks and hollow attempts to bend the data to their will; they claim that surface warming is plateauing, but this is a cherry-picked reading that ignores the consistently upward trend over several decades and also ignores ocean warming .

Some simply contradict the thousands of experts who have worked for years on this data, or indulge in personal attacks. Others accept climate change but insist humans are not at fault, but this is patently untrue. The vast quantities of CO2 we pump into our besieged atmosphere bear unmistakably anthropomorphic tell-tale chemical traces that place the smoking gun firmly in our hands.

Rather depressingly, denialists are ubiquitous in media and politics. Australia has just elected Tony Abbot to office, a man who calls climate change “absolute crap”. Many Republican politicians in the US and a smattering of British Conservatives reject the very notion that human activity affects climate – columnists from James Delingpole to David Rose pour scorn on the scientific consensus, despite having no qualification to do so. Increasingly, denialism is associated with those on the right of the political spectrum, those who detest regulation and baulk at corrective measures.



Pragmatic choices

Climate change affects everyone and must transcend ideology so pragmatic choices can be made. This of course goes both ways; ideological opposition to nuclear power must be reconsidered in light of the evidence confirming it as safe, efficient and clean, rather than the emotive rhetoric that has long blighted discussions on energy production and kept us tethered to fossil fuels .

Climate is a deeply complex system, not a simple thermostat. Increased global warming can have seemingly paradoxical consequences – the extreme cold snap across Europe in March is an illustration of this; Arctic sea-ice has decreased 80 per cent in just 30 years, allowing surplus heat to modulate air circulation, leading to arctic conditions in the Northern hemisphere. Research this year has shown this year that the devastation of Hurricane Sandy was exacerbated by climate change and we can expect more violent weather events. Melting land ice has raised sea-levels a worrying 19cm since 1901.

Worse than this, depleting ice-sheets increase tectonic and volcanic activity as the confining loads on these systems are stripped away, increasing seismic activity.

Corrective action is urgently needed but requires sustained social and political pressure, all too easily derailed by “false balance” and misinformation.

There is no debate and zero ambiguity; climate change is real and it’s about time we got angry when denialists attempt to equivocate the unequivocal. Climate denialists are pushing a scientific fallacy on a global scale. Unchallenged they risk taking us all down with them.



Dr David Robert Grimes (@drg1985) is a physicist at Oxford University. He blogs at davidrobertgrimes.com