Climate change seems like an abstraction when it’s snowing outside, an imagined future rather than the kind of immediate danger we have evolved to react to.

As a test of our capacity for reason, the climate-change conundrum proves just how conceited it is to describe ourselves as homo sapiens. Perhaps COP15 should have been held in Cancun or Nairobi or Cairns, where the weather is more likely to help us be reasonable.

While they pride themselves on their superior rational capacity, in truth the climate deniers are the least wise of the homo sapiens who’ve gathered in Copenhagen. The crackpots, fringe-dwellers and engineers make up one side of the debate, speaking with a voice that has reached hysterical pitch after the theft of emails from the University of East Anglia.

UN officials have been stampeded into responding to “climategate”, although the stolen emails have political meaning only in the Republic Party in the United States and the right wing of the Liberal Party in Australia, in charge until the next election.

Climate denialism would barely register if not for the internet, the modern curse of communication that provides ready confirmation for every whacky theory or paranoid delusion.

The other day a study found that one in four Australians uses the internet to diagnose and treat their illnesses without the need to consult a medical expert. “It’s hard sometimes on the net to work out whether opinion is being portrayed as fact,” said the AMA president. Amen to that.

If a climate denier ignores expert opinion and uses the internet to diagnose and treat his cancer and dies as a result, it is regrettable. If he does the same for his daughter and she dies it is irresponsible. If he ignores the experts and uses the net to conclude the Earth is not sickening and other people’s children die then he is guilty of a crime.

Yesterday we learnt what we already knew — that the hackers were professionals. What we don’t yet know is who organised and paid for the hack. No doubt the money trail is well-hidden, so we must ask who benefits most. Cui bono? The finger points unwaveringly in one direction, the fossil fuel industry’s think tanks in Washington.

But it’s not only the sceptics who are repudiating the science in Copenhagen; most of the nations gathered here are doing the same, including the major emitters who cling to the fantasy that warming can be limited to 2°C above the pre-industrial average.

To have a good chance of that outcome, developed countries would need to cut their greenhouse gas emissions by 25-40% below 1990 levels by 2020 and developing countries as a group would need to cut theirs by 15-30% below the “business-as-usual” levels expected by 2020. Only the European Union comes close to an adequate response.

Even if Copenhagen were to reach a binding agreement, current commitments would fall well short of these targets. Climate Analytics estimates that existing pledges would see global emissions continue to grow through to 2040, and warming would reach 3-4°C by before the end of the century.

A four-degree world is almost too intimidating to contemplate, yet that’s where we are headed.