What’s the News: Two hundred million years ago, half of the Earth’s species vanished in the blink of a geological eye, clearing the way for rise of the dinosaurs in the Jurassic. The cause of that mass extinction, a new study suggests, may have been gigatons of methane released from the sea floor after a slight rise in the earth’s temperature, triggering much greater warming. And if that sounds familiar, it’s because scientists are worried the same thing will happen today.
World carbon emissions fell by 1.3 percent in 2009, most likely due to the global recession, says a report from the Global Carbon Project published today in Nature Geoscience. Emissions were originally expected to drop further (about 3 percent, as estimated from the expected drop of world GDP), but China and India’s surging economies and increasing carbon output countered the decreases elsewhere.
The largest decreases occurred in Europe, Japan and North America: 6.9% in the United States, 8.6% in the U.K., 7% in Germany, 11.8% in Japan and 8.4% in Russia. The study notes that some emerging economies recorded substantial increases in their total emissions, including 8% in China and 6.2% in India. [USA Today]
There is some good news from the report. It seems the atmospheric CO2 concentrations didn’t jump as much as they were expected to, which means the world’s carbon sinks were performing better.
While emissions did not fall much, the amount of CO2 in the atmosphere increased by just 3.4 gigatonnes – one of the smallest rises in the last decade. Friedlingstein says the land and marine sinks performed better in 2009, because the La Niña conditions in the Pacific meant the tropics were wetter, allowing plants to grow more and store away more carbon. [New Scientist]
When researchers rack up the carbon emitted across the world, the standard trends emerge: Europeans put less CO2 into the atmosphere than Americans, but China’s rapid ascent is sending its emissions shooting past those of the United States. However, this week in the Proceedings of the National Academy of Sciences, Stanford University researchers attempt to rejigger the numbers to reflect not just where the emissions are produced, but who is responsible for them—who’s buying and consuming the products that cause those emissions.
After study global trade databases, Steven Davis and Ken Caldiera say that in 2004, 23 per cent of global CO2 emissions – some 6.2 gigatonnes – went in making products that were traded internationally. Most of these products were exported from China and other relatively poor countries to consumers in richer countries [New Scientist]. The researchers say that developed countries outsource about a third of the carbon dioxide emissions connected to their consumption.
In a bit of unexpected climate related good news—not for us, of course—some shell-building ocean dwellers like blue crabs, shrimp, and lobsters may actually benefit from increased ocean acidification. This surprising finding seems to be good news for lobster lovers, but researchers note that the ongoing acidification still appears to spell trouble for many marine creatures.
Scientists now think that acidifying oceans may allow these select crustaceans to build stronger shells and exoskeletons, instead of making them more brittle. Carbon dioxide (CO2)—the notorious byproduct of fossil fuel burning—dissolves in the ocean. That makes the ocean more acidic. It also reduces the number of so-called carbonate ions in seawater, and these ions are among the primary materials that sea creatures use to build their calcium carbonate shells and skeletons [LiveScience]. Justin Ries, a coauthor on the new study, speculates that these bottom dwellers are somehow better able to manipulate CO2 ions to build their shells, even though fewer CO2 ions are available to them in an acidic environment. However, exactly how they accomplish this is unknown.
When people breathe in carbon dioxide, they start to panic. It happens in mice and other animals, too, as the body responds to the threat of suffocation. Now, in a study in Cell, researchers have connected a particular gene to that response in the brain.
The gene, called ASIC1a, is connected to a protein found in abundance in the amygdala, the area scientists believe to be the brain’s fear center. In their new study … the researchers show that mice lacking this gene don’t freeze in place–a commonly used indicator of rodent fear–to the extent that normal mice do when the team pumped CO2 into their enclosure. But when Wemmie and colleagues injected a virus containing the ASIC1a gene into the amygdala of the mice, they acted like normal mice, freezing up when exposed to elevated CO2 [ScienceNOW Daily News].
This week in Nature Geoscience, a cadre of scientists going by the name Global Carbon Project will publish a meta-analysis of global carbon emissions. The study led to headlines like, “Global CO2 emissions to drop 2.8 pct in ’09: report,” and many others more in the ominous vein of “Earth ‘heading for 6C (6 degrees Celsius)’ of warming.” So how did both headlines come from the same study?
This year’s dip is correct: “In 2009, it is likely that the global financial crisis will cause global emissions to actually fall by a couple of percent,” said Michael Raupach, co-author of the report and co-chair of the Global Carbon Project [Reuters]. But, he says, the carbon cut will be short-lived if the recession ends.
In that case, the researchers say, the world will return to its normal trend. Since 2000 emissions have been rising by an average 3.4 per cent every year, compared to one per cent in the 1990s [The Telegraph]. Overall, worldwide emissions rose by 29 percent from 2000 to 2008, and the scientists put forward that 6 degrees Celsius global warming figure as a worst-case scenario—what could happen if the overall rising trend continued unabated.