The good news: The World Bank reports that the proportion of the world's population living in extreme poverty fell from 29 percent in 1990 to 18 percent in 2004.

The bad news: The numbers are almost entirely due to China and India's economic growth -- especially China's. The World Bank says that between 1981 and 2004, the number of people living in extreme poverty in China declined by 500 million. But in sub-Saharan Africa and Latin America, while the proportion living in extreme poverty dropped slightly, rapid population growth ensured an absolute increase in the number of extreme poor.

The really bad news: This year or next, says the International Energy Agency, China -- which is reportedly building a new coal-fired power plant every four days -- will pass the U.S. as the world's leading emitter of greenhouse gases.

(Americans can take heart, though -- individual U.S. citizens are still No. 1: responsible for some 20 metric tons of carbon dioxide emissions per person per year, as opposed to China's 3.2 tons.)

The dots are easy to connect. There ain't no free lunch. China's amazing accomplishments in poverty reduction have been accompanied by industrial growth that threatens the entire planet's ecosystem. And in an extra dire twist, those who remain the worst off in Africa and Latin America are likely to pay the biggest price for climate change.

UPDATE: A reader points out that I should have specified "carbon dioxide" emissions instead of "greenhouse gas" emissions in the sentence on per capita comparison between the U.S. and China. I've corrected that sentence.