Another Kind of Downturn?

The global economic meltdown is perceptibly slowing the wheels of industry. It is idling factories, delaying construction projects, and curbing the consumer demand that starts the engines of myriad delivery trucks every day.

Economists whose predictions are on the gloomier end of the spectrum predict that the world has not come close to seeing the worst. If that’s so, it may be possible that the current financial malaise could leave a distinctive mark on one of the world’s most famous climate records that originated at Scripps Institution of Oceanography at UC San Diego.

The Keeling Curve has measured the steady rise of society’s expulsion of carbon dioxide into the atmosphere for the past 50 years and today measures about 386 parts of carbon dioxide per million parts of air, up from 315 ppm in 1958. The concentration of the greenhouse gas most strongly associated with the planet’s observed warming has never failed to tick upward over the years but not always at the same rate. Researchers have attributed mini spikes and taperings to phenomena ranging from El Niño cycles to volcanic eruptions.

So how big would a drop-off in industrial activity have to be before it registers on the Keeling Curve?

“If (economic) growth rate slacks off for a couple of years, it’ll show up,” said Ralph Keeling, a Scripps geochemist who has continued the measurement series named for his late father Charles David Keeling.

Such a slack off is predicted for China. That country became the world’s leading emitter of CO₂ last year thanks largely to a proliferation of the coal-fired power plants that have stoked the country’s exploding economy, but in the wake of the downturn, its rise could become less meteoric. A recently publicized projection by a Stanford University team of China’s carbon dioxide output anticipates a possible drop of up to 2.6 billion tons of CO₂ between now and 2010. If that comes to pass, Keeling estimates it would drop the concentration of CO₂ in the air as measured by the Keeling Curve by about one-third of a part per million.

 It wouldn’t be the first instance in which hard times left a climatic imprint. Previous records suggest that the Great Depression triggered a 25 percent drop in carbon dioxide emissions between 1929 and 1932.

But Keeling said such a slight fluctuation in CO₂ readings in the present day would be difficult to attribute specifically to China’s slowed production, considering the myriad variables that influence readings. He likened the act of linking that country’s slowed economic activity and less CO₂ to measuring the volume of a tub of water to find evidence that it is filling at a slower rate. To make the analogy complete, he said, the bathtub would also have to be filled with waves. 

“The point is that it’s hard to see an effect immediately, but with time it will show up,” he said.

Of course, China is not the only country reducing its industrial output and a worldwide drop-off of CO₂ emissions would be expected to be larger. There is no exact equivalent to the Stanford projection of Chinese industrial activity for the rest of the world or for the second-biggest emitter, the United States. There are, however, some proxies that could serve as a guide to things to come: The Department of Energy reported that consumption of coal for power generation dropped about 4 percent in fall 2008 from the previous year and the International Energy Agency estimated that worldwide demand for oil was expected to drop by nearly 1 million barrels per day in 2009 in a falling-off widely tied to the global financial crisis.

An aggressive shift toward energy efficiency and alternative energy sources — an oft-stated pledge of the new Obama Administration — could also make a dent in the Keeling Curve of a more lasting, and less painful, nature.

“An economic collapse is obviously not the desired solution to slowing CO₂ growth,” Keeling said.  “What we need is alternate energy, which may provide economic stimulus without CO₂ emissions.”

—Robert Monroe