"It seems highly likely to me that climate change poses a major problem for the planet. I say “highly likely” rather than “certain” because I have no scientific aptitude and remember well the dire predictions of most “experts” about Y2K. It would be foolish, however, for me or anyone to demand 100% proof of huge forthcoming damage to the world if that outcome seemed at all possible and if prompt action had even a small chance of thwarting the danger."