The Stern Report (Cost of Global Warming.)

[The once and future king]

The Stern report was commisioned by Her Majestys Treasury and was carried out by Lord Stern a renowned economist.

Stern report. (Long and short versions and other documents.)

To fuel debate I will quote this from the executive summary (short):

[ QUOTE ]
Using the results from formal economic models, the Review estimates that if we don’t
act, the overall costs and risks of climate change will be equivalent to losing at least
5% of global GDP each year, now and forever. If a wider range of risks and impacts
is taken into account, the estimates of damage could rise to 20% of GDP or more.
In contrast, the costs of action – reducing greenhouse gas emissions to avoid the
worst impacts of climate change – can be limited to around 1% of global GDP each
year.

[/ QUOTE ]

That should get the party started.