UK report - cost of climate change is 20 times the cost to stop it

On October 30th the UK government released the Stern Review on the Economics of Climate Change. Here is good summation from the press release, with a few items of note highlighted:

The first half of the Review focuses on the impacts and risks arising from uncontrolled climate change, and on the costs and opportunities associated with action to tackle it. A sound understanding of the economics of risk is critical here. The Review emphasises that economic models over timescales of centuries do not offer precise forecasts – but they are an important way to illustrate the scale of effects we might see.

The Review finds that all countries will be affected by climate change, but it is the poorest countries that will suffer earliest and most. Unabated climate change risks raising average temperatures by over 5°C from pre-industrial levels. Such changes would transform the physical geography of our planet, as well as the human geography – how and where we live our lives.

Adding up the costs of a narrow range of the effects, based on the assessment of the science carried out by the Intergovernmental Panel on Climate Change in 2001, the Review calculates that the dangers of unabated climate change would be equivalent to at least 5% of GDP each year.

The Review goes on to consider more recent scientific evidence (for example, of the risks that greenhouse gases will be released naturally as the permafrost melts), the economic effects on human life and the environment, and approaches to modelling that ensure the impacts that affect poor people are weighted appropriately. Taking these together, the Review estimates that the dangers could be equivalent to 20% of GDP or more.

In contrast, the costs of action to reduce greenhouse gas emissions to avoid the worst impacts of climate change can be limited to around 1% of global GDP each year. People would pay a little more for carbon-intensive goods, but our economies could continue to grow strongly.

The key point is that the climate change could cost us 20 times what it would cost to limit it. If you don't think 20% is too high, that was about the drop in economic output during the Great Depression.

All the more reason we need to use a portion of the pension fund to invest in energy conservation and renewable energy in Massachusetts.

Also, Steve Connor of the Independent in the UK summarizes the Stern Review's description of the effects of global climate change at different temperature increases.