Government Sees Slight Decline In Greenhouse Gases -- Cites Renewables

Emissions of greenhouse gases in the United States dropped a small but eye-catching 1.5 percent between 2005 and 2006, according to a new inventory (which can be accessed here) put forward by the Environmental Protection Agency. The EPA cited a number of reasons for the decrease -- which saw the first drop in carbon dioxide emissions since 2001 -- including greater reliance on renewable power generation.

Overall, according to the annual Inventory of Greenhouse Gas Emission and Sinks, the amount of pollutants believed to contribute to global climate change decreased by about 1.5 percent. Carbon dioxide from fossil fuel combustion was down by 1.9 percent.

    

Some of the reasons for the change, according to the report, included an 8.1 percent increase in the amount of electricty generated by renewable power sources, such as hydroelectric plants, which themselves boosted production by some 7 percent. However, there was a touch of irony in other findings. For instance, the EPA reported that warmer winter weather helped contribute to the trend:

"This decrease [in carbon dioxide emissions] is primarily a result of the restraint on fuel consumption caused by rising fuel prices, primarily in the transportation sector, an increase in the cost of electricity, and decreases in the cost of natural gas. Additionally, warmer winter conditions in 2006 decreased the demand for heating fuels."

The report goes on to say that the winter "was significantly warmer than usual" but that summer temperatures were cooler than normal. 

The report also noted that 2006 emissions of carbon dioxide from burning fossil fuels was still 19 percent above the 1990 baseline. Overall greenhouse tonnage has increased by more than 14 percent during that time, while the nation's economy has grown nearly 60 percent, according to the EPA. According to a chart in the report, 2001 was the last year carbon dioxide emissions dropped compared to the year before.

Among other intriguing highlights in the mass of figures: carbon dioxide emissions from coal-fired electricity generation declined by 1.3 percent from a year earlier but those from petroleum generation plunged by a whopping 45.5 percent. It was not immediately clear what drove the large decrease in emissions from petroleum-fired generation. Meanwhile, emissions from natural gas generation climbed by more than 6 percent. 

Compiled in collaboration with other federal agencies, the document was published in the Federal Register on March 7, triggering a 30-day comment period. Eventually, the report will be submitted to the Secretariat of the United Nations Framework Convention on Climate Change.

(Photo: Bonneville Dam hydroelectric project, Columbia River, Oregon and Washington; Wikipedia photo)