We're not making this any easier for ourselves. Like an already-overweight person who just keeps packing on the pounds--making his weight-loss goal even harder to achieve should he ever go on a diet--we're heading in the wrong direction if we want to avert a climate crisis caused by loading the atmosphere with carbon dioxide.

To stabilize the amount of carbon dioxide, we have to throttle back emissions radically, not merely slow the rate of increase. But we can't manage even the latter. During the 1990s, worldwide emissions of carbon dioxide (mostly from burning fossil fuels such as coal, oil and natural gas) increased at a rate of 1.1 percent per year. In other words, in the years right after the climate pact reached at the Rio "earth summit," we didn't exactly cover ourselves with glory. But it gets worse! Between 2000 and 2004, the rate increased to 3.1 percent per year, finds a study published this evening in the online edition of the Proceedings of the National Academy of Sciences.

Why? We're using more energy to produce each unit of gross domestic product; that's the polar opposite of energy efficiency, which means being just as productive with less energy. In addition, the energy we're using has ever-more carbon in it rather than less, which is what would happen if we substituted sources such as wind and nuclear energy for coal. Both trends--increases in "energy intensity" and carbon intensity--are reversals of the decades-long movement toward greater energy efficiency and reduced carbon intensities.

"Despite the scientific consensus that carbon emissions are affecting the world's climate, we are not seeing evidence of progress in managing those emissions in either the developed or developing countries. In many parts of the world, we are going backwards," said Chris Field, director of the Carnegie Institution's Department of Global Ecology, who led the study.

And for all those greenhouse deniers who charge that the Intergovernmental Panel on Climate Change (IPCC) is a bunch of Cassandras, the PNAS study has news for you. Those IPCC-scenarios of how much worldwide CO₂ emissions might rise over the years? Actual global emissions since 2000 grew faster than in the worst of the worst-case scenarios. Things are, as Field says, "definitely headed in the wrong direction."

The accelerated CO₂ emissions are greatest in the exploding economies of the developing world, particularly China. Although developing countries contribute only about 40 percent of emissions, in 2004 73 percent of the growth in global emissions came from them.

Not to belabor the analogy of the overweight man, but as we pour ever-more CO₂ into the atmosphere the task of keeping concentrations below 580 parts per million (double pre-industrial levels, which is widely viewed as a point where serious sea-level rise, more intense storms and heat waves, and droughts kick in) is getting harder and harder. If he already weighs 250 and hopes to one day get down to 180, climbing to 300 puts the eventual target even further out of reach. Back to climate, the core problem is that a molecule of CO₂ stays in the atmosphere for about 100 years. That means that if we add even a little today "say we cut emissions in half "the overall concentration will still keep rising. As a result, future emissions cuts will have to be even more drastic if we are to actually make CO₂ level off, let alone fall if we find that future levels have produced a true climate crisis.