A leading critic of the environmental movement is questioning the conclusions of the latest British report on global warming. Danish professor Bjorn Lomborg argues that money spent to combat global warming is a comparatively poor investment.

The British-government report warns that human-induced climate change could cost between five and 20 percent of global economic output every year.

The report by former World Bank chief economist Nicholas Stern recommends spending one percent of global output a year, starting immediately, to curb greenhouse gas emissions. He calls the corresponding increase in prices "manageable", and argues that failure to do so could trigger a catastrophe akin to the world wars or the Great Depression.

But Danish statistician Bjorn Lomborg argues that money spent to combat global warming would be better spent on other pressing social needs.

Lomborg is the author of a controversial 2003 book titled The Skeptical Environmentalist. He was at the United Nations for a conference with ambassadors and experts on how to most efficiently invest limited resources to meet the long list of global challenges.

Lomborg says when the government participants were asked to prioritize challenges, they made the fight against communicable diseases their top priority. Combating global warming was far down the list.

"The main issue here is not to say that climate change is not an important issue," he said. "And that it will have serious consequences, but the question is to ask, with limited resources, where can you do the most good. If you invest in climate change policies, you will help especially third world countries a hundred years from now, but if you invest in some of the other things, you will help people right now."

Lomborg is not a scientist or an economist. He was a professor of statistics in Denmark before writing his book questioning the data used to predict the effects of climate change. He says the Stern Report's prediction on the economic damage bear close scrutiny.

"Even by the worst estimates of the Stern Report, which is saying 20 percent, now you have to remember that's factoring in a lot of dubious environmental qualities and it's also factoring in, it goes from 13 percent to 20 percent just simply by weighing the developing countries higher, which quite frankly I don't quite understand how you do, but let's just go with that 20 percent," he said. "They talk about the fact that this is a Second World War or Great Depression, so you have to remember this happens over 100 years, so even if you take the worst-case analysis, we're talking about a 20 percent reduction over 100 years.

Lomborg agrees that nations, especially the largest and wealthiest, must limit greenhouse gas emissions. But he argues that the costs of current international initiatives such as the Kyoto Treaty are too expensive for the good they hope to accomplish.

The Bush administration opposes the Kyoto Protocol and has not signed it.