There's a big difference between predicting the exact weather for a day two months in the future (impossible) and predicting general global climate changes (possible through scientific extrapolation). The difference between Earth's average temp. from year to year is rising exponentially, the polar ice caps are melting, water levels are rising, and it's all going to get much much worse according to him. I bet you won't be so concerned about the carbon tax then. You can choose to believe or not believe him, but good luck finding a more qualified source.