Rising Global Temperature, Rising Uncertainty

In recent years, climate modelers have become increasingly certain of the reality of global warming, but at the same time they are paradoxically becoming less certain in their predictions of the amount of future warming. Yet as climatologists9 appreciation of climate prediction9s large and perhaps unresolvable uncertainties grows, they remain steadfast in advising policy-makers that the threat justifies action. As policy-makers deal with uncertainties in greenhouse models, they may find some lessons in the lingering effects of acid rain long after controls were imposed (see p. 195).