US better on emissions when climate taken into consideration, says study

New research suggests the US fares better when considering climate than many other countries. A new method of calculating equivalent emissions means many countries have perhaps been portrayed incorrectly.

"Increased concern about carbon dioxide emissions has resulted in efforts to create methods for ranking countries according to their emissions," said Michael Sivak, director of Sustainable Worldwide Transportation at the U-M Transportation Research Institute. "Such rankings inform policy decisions on an international scale. The more comprehensive these rankings are, the better our chances of reducing emissions."

The new rankings not only take account of population and GDP, but also the heating and cooling demands imposed by the climate. "A system that includes the variable of local climate provides a fairer measure of carbon dioxide emissions," Sivak said. "Our approach involves adjusting the amount of emissions in accordance with the total number of heating degree days and cooling degree days."

The new rankings benefit the US greatly, moving it up 52 places in the overall rankings. It was still 100th out of 157 countries studied however. Other countries to show improvement were generally cold weather countries including Finland, Russia, Norway and Slovakia. Many African countries dropped down the list as a result of the new method.

The leading countries are in fact Chad, Afghanistan, Mali and Niger, with the worst being South Africa, Uzbekistan and Trinidad and Tobago. In fact South Africa, using this new method, emits 61 times more greenhouse gas emissions than Chad.

"Overall, our results suggest that taking climate into account makes a significant difference in how countries fare in carbon dioxide emissions rankings," Sivak said. "Because people respond to the climate they live in by heating and cooling indoor spaces, an index that incorporates climate provides a fairer yardstick than an index that does not."