In his report, Stern overstates（）

A. the remedies for a possible economic slowdown
B. the necessity for a sustainable economic growth
C. the costs of minimizing the effects of global warming
D. the ers global warming may cause to the world

It seems impossible to have an honest conversation about global warming. I say this after ditly perusing the British government’s huge report released last week by Sir Nicholas Stern, former chief economist of the World Bank and now a high civil servant. The report is a piece of misleading public relations. It foresees dire consequences if global warming isn’t curbed: a worldwide depression and flooding of many coastal cities. Meanwhile, the costs of minimizing these awful outcomes are small: only 1 percent of world economic output in 2050.

No sane person could fail to conclude that we should conquer global warming instantly, if not sooner. Who could disagree Well, me. Stem’s headlined conclusions are intellectual fictions. They’re essentially fabrications to justify an aggressive anti-global-warming agenda. The er of that is that we’d end up with the worst of both worlds: a program that harms the economy without much cutting of greenhouse gases.

Let me throw some messy realities onto Stern’s tidy picture. In the global-warming debate, there’s a big gap between public rhetoric and public behavior. Greenhouse emissions continue to rise despite many earnest pledges to control them. Just last week, the United Nations reported that of the 41 countries it monitors (not including most developing nations), 34 had increased greenhouse emissions from 2000 to 2004. These include most countries committed to reducing emissions under the Kyoto Protocol.

Why is this In rich democracies, policies that might curb greenhouse gases require politicians and the public to act in exceptionally "enlightened" ways. They have to accept "pain" now for benefits that won’t materialize for decades, probably after they’re dead. And even if rich countries cut emissions, it won’t make much difference unless poor countries do likewise and so far, they’ve refused because that might jeopardize their economic growth and poverty-reduction efforts.

The notion that there’s only a modest tension between suppressing greenhouse gases and sustaining economic growth is highly dubious. Stern arrives at his trivial costs—that 1 percent of world GDP in 2050—by essentially assuming them. His estimates presume that, with proper policies, technological improvements will automatically reconcile declining emissions with adequate economic growth. This is a heroic leap. To check warming, Stern wants annual emissions 25 percent below current levels by 2050. The IEA projects that economic growth by 2050 would more than double emissions. At present, we can’t bridge that gap.

The other great distortion in Stern’s report involves global warming’s effects. No one knows what these might be, because we don’t know how much warming might occur, when, where, or how easily people might adapt. Stern’s horrific specter distills many of the most terrifying guesses, including some imagined for the 22nd century, and implies they’re imminent. The idea is to scare people while reassuring them that policies to avert calamity, if started now, would be fairly easy and inexpensive.