Formulating Greenhouse Policies in a Sea of Uncertainty

To prevent major global climate change all countries must begin to act now. However, there is no agreement on how rapidly greenhouse gases will be emitted over the next century, how rapidly they will accumulate in the atmosphere, what will be the cost of abatement, how large the climate change will be, or even whether the change will be predominantly beneficial or harmful. Beyond agreeing that greenhouse gases are likely to result in atmospheric warming, other factors held constant, there is no consensus on any of these questions.