The latest report on global warming reveals the trade-offs and uncertainties in forcing changes.
Buy a fluorescent bulb and stop a hurricane? It's not that easy. A new climate-change report finds voluntary conservation and the use of clean energies together won't be enough to slow global warming. Rather, strict rules on greenhouse gases will need to pinch lifestyles. And the biggest price? A crimp on world economic growth.
These sober projections were issued last week by the Intergovernmental Panel on Climate Change in a consensus document written with input from more than 2,000 experts and approved by more than 100 governments.
This latest IPCC report should serve as an action plan for the planet. And in fact, a G-8 summit will take it up in June with hopes that rich nations can push for a post-Kyoto treaty this year. It should also guide legislation in Congress aimed at greater fuel efficiency in vehicles and investments in alternative energies.
The report's key projection is that the kind of tough emissions-reduction schemes to prevent a severe temperature rise of 3 to 4 degrees F. would result in 3 percent less global economic growth by 2030 (or 5.5 percent less by 2050).
Hold on, says the White House: Such a drop in GDP would amount to a recession. But IPCC economists – and it is far more difficult to get a consensus among economists than climate scientists – counter that this economic slowdown would be mild compared with the disasters that might be averted by the recommended mitigation steps.
Other experts, such as Yale economist Robert Mendelsohn, contend that the net economic impact of climate change will be surprisingly small over the next century. If true, then a 3 percent GDP reduction may be too much to pay.