Introduction - Beyond Smoke and Mirrors - page 4

problem so they should fix it, and poor countries should

not be asked to slow their economic development. How-
ever, they are growing so fast that according to projec-
tions, the developing world will add as much greenhouse
gas to the atmosphere in this century as the industrialized
nations will have contributed in the years from

. We all live on the same globe, the actions
of one affect all, and this problem cannot be solved with-
out all working together.
There are three parts to this topic. Part I is on
climate change itself and explains what we know, what
we don

to

t know, what the uncertainties are in predictions
of the future, and how urgent is the need for action.
The section discusses what can be learned from the
past, how the future is predicted, the many models
that are used, and what they predict. The models are
not yet good enough to converge on a single number
for the expected temperature increase because the
science is not that perfect. Uncertainty is used by
some as an excuse for inaction, but it should not be,
because by continuing

'

(BAU) the
predictions for the end of the century range from ter-
rible at the high end of the predicted increase (about

“ business as usual ”

For C) to merely very bad at the low end (about

C).
Part II begins with what we need to do in controlling
greenhouse gas emissions to limit the ultimate tempera-
ture rise. It is too late in this century to return the atmos-
phere to what it was like before the start of the industrial
age. I include my estimate of the allowable upper limit on
greenhouse gases, the amount beyond which the risk of
sudden climate instability greatly increases.

For