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When Temperatures Plummet, Greenhouse Gases Rise — Especially When You Idle Your Car

Plumes of steam blow from the Wyman station power plant on Cousins Island in Yarmouth, Maine, where the temperature at dawn was several degrees below zero on Thursday, Jan. 8, 2015. CREDIT: AP/ROBERT F. BUKATY
Plumes of steam blow from the Wyman station power plant on Cousins Island in Yarmouth, Maine, where the temperature at dawn was several degrees below zero on Thursday, Jan. 8, 2015. CREDIT: AP/ROBERT F. BUKATY

Much of the United States is being pummeled by an Arctic cold front this week one year after a similar one occurred last year. Aside from being unpleasant, these cold stints represent elevated periods of greenhouse gas emissions.

Across the Midwest and Northeast schools are closed, roads are hazardous, and staying indoors is advised. This frigid weather front has crystallized the denial harbored by those unwilling to accept the overwhelming science of climate change, causing some to rise up and claim that cold weather is just one more sign that man-made global warming is a hoax. This has been shown to be a false assertion many times. In fact, 2014 was the hottest year globally on record.

Extreme cold weather makes many long for the scorching days of summer. The increased energy and fuel needs we call upon during these freezes can contribute to overall GHGs; subsequently adding to the warming making those summer days all the more severe. So as these seasons may seem world’s apart, they are atmospherically intertwined. For example, just as the U.S. is gripped by cold, Australia is battling through one of its most treacherous heat waves in memory.

According to the Energy Information Agency (EIA), cold weather was the main reason carbon dioxide emissions rose by 2.5 percent domestically in 2013. Compared with 2012, in 2013 there were 18 percent more days where cold weather was severe enough to cause a spike in energy demand. This added electricity demand, and associated emissions, was especially prominent in the residential sector, which accounted for nearly half the total emissions increase across sectors.

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One of the worst parts of winter weather is leaving a toasty house or office for a car that feels like its gone into an extended deep freeze to get through the season. Many shivering drivers will sit idly in the car, blowing on their hands, waiting for the vehicle warm up before shifting into gear. It is common belief that this is good for the car, however the truth is that’s its bad for the climate and can contribute up to 1.6 percent of total U.S. GHGs per year. According to the Environmental Defense Fund (EDF), idling a car, which means keeping the engine running while the car is stopped, for more than ten seconds wastes more gas than restarting the engine.

The EDF recommends that drivers warm up a vehicle’s engine by driving it, not idling. Modern engines use an electronic mechanism to mediate fuel injection into the engine as opposed to old cars that relied on carburetors that actually did benefit from a warming up period. So the technology has moved on, but the myth hasn’t.

This doesn’t mean one should turn their car off when waiting at a long stoplight or when stuck in traffic, technological advances have also helped with that. Start-stop technology, which is a new but growing feature in U.S. cars, can turn off an engine automatically when a vehicle comes to a complete stop. When the vehicle moves again, the engine restarts. Recent tests have shown that these systems can provide a five to seven percent improvement in fuel economy and associated carbon dioxide emissions. This could save drivers up to $179 per year in fuel costs, according to Greg Brannon, Director of AAA’s Automotive Engineering and Industry Relations team. That’s a significant cost reduction, and the GHG reduction could be significant too.

One 2009 study in the journal Energy Policy tried to determine how much vehicle idling contributes to GHG emissions. The study found that idling accounts for over 93 million metric tons of CO2 and 10.6 billion gallons of gasoline a year, equaling 1.6 percent of all U.S. emissions. According to the EPA, in 2012 U.S. accounted for 6,526 million metric tons of carbon dioxide equivalents, which would make 93 MMt about 1.4 percent of total emissions. The transportation sector accounted for 28 percent of total domestic GHG emissions in 2012, meaning that idling would have made up between four and five percent of total transportation emissions.

One thing that can help alleviate the elevated GHGs and energy costs associated with cold snaps is the use of renewable energy, especially wind power, which is prevalent throughout the Midwest where these Arctic drops frequently occur. According to new data released by the American Wind Energy Association (AWEA), wind power saved consumers $1 billion over two days last year during the early January cold blast. These savings derived from wind power generation preventing spikes in the prices of fossil fuels during periods of extremely high demand.

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“With extreme cold now moving through much of the Midwest and Eastern U.S., wind energy is once again helping to keep the lights on and protecting consumers against costly energy price spikes,” said Michael Goggin, Director of Research for AWEA, during a conference call on Wednesday.