Al Gore says the science on global warming is clear and there is a major problem. Vaclav Klaus, Czech president, contends that climate change forecasts are speculative and unreliable. Whose claims are scarier?

Of course, Mr Klaus exaggerates (he is a politician) but if he is partly right, we should be more concerned, not less. Consider an analogy. If, like many of my neighbours in Oxford, you believe that new building exacerbates flooding, how would you feel if models that predicted bad news were discredited?