General Motors said this week it will cut out a climate-destroying chemical from its car air conditioners by 2013, in a first for an industry seeking greener auto coolants.
The car giant will stop using HFC-134a -- a "super greenhouse gas" -- in all new Chevrolet, Cadillac, Buick and GMC models made in the United States, and replace it with a climate-friendlier coolant. Environmental advocates heralded the move.
"It's a major step forward toward a global mobile air conditioning partnership that takes its environmental and sustainability obligations seriously," Durwood Zaelke, president and founder of the Institute for Governance and Sustainable Development (IGSD), a non-profit group, told SolveClimate News.
Zaelke said he expects other U.S., European and Japanese automakers to follow suit.
Alexander von Bismarck, executive director of the Environmental Investigation Agency (EIA), a Washington, D.C.-based non-profit watchdog, called the decision "the beginning of the end for an entire class of greenhouse gases."
'Biggest Climate Opportunity'
HFC-134a is 3,830 times more potent a greenhouse gas than carbon dioxide, with a lifetime of 14 years in the atmosphere, according to scientific research published in the Proceeding of the National Academy of Sciences (PNAS).
The GM alternative, called HFO-1234yf, has a global warming potential that is four times that of CO2 and exists for only 11 days.
Also known as "super" GHGs, HFCs were developed to replace ozone-eating gases that were banished under the 22-year-old Montreal Treaty, signed by 196 nations. So far, the treaty has retired some 100 chemicals linked with ozone destruction; but it has also stoked the production of HFCs, which are safe for the ozone but are extremely powerful greenhouse gases.
If left unchecked, the man-made HFCs could account for 28 to 45 percent of global greenhouse gas emissions by 2050, warns the PNAS findings.
In the U.S., they are the fastest-growing source of warming pollution and are predicted to skyrocket an "astronomical" 140 percent by 2020 over 2005 levels, compared to four percent growth for the nation's total emissions, Zaelke said.
Currently, mobile air conditioning covers 40 percent of the U.S. HFC footprint. Worldwide, the sector makes up one-third of all HFC uses, with a major boost expected due to a rapid rise in prosperity in developing nations like China and India.
Knocking out HFCs "represents the single biggest climate opportunity in the world today," especially "now that the U.S. has decided not to act this year [on climate legislation]," Zaelke said.
A Cure Worse than the Disease?
But not all advocates see HFO-1234yf as the solution.
BeyondHFCs, a Brussels-based international network of organizations that includes EIA and is pushing for "natural" refrigerants, says adoption of HFO-1234yf would create more environmental damage.
According to the group, tests show the substitute can cause "incalculable risks for humans" in the case of a car accident.
"The environmental impact of HFC1234yf comes when, vented into the atmosphere, it decomposes into trifluoroacetic acid (TFA) which, leached out from the atmosphere by the rain, develops a herbicide effect," the group said in a statement.
Christianna Papazahariou, head of BeyondHFCs, called GM's decision "to ignore all safety and environmental warnings" concerning HFO-1234yf "very worrying."
"We hope that the car industry will not suffer from a toxic dependence on 1234yf," she said.
The campaign is advocating for CO2-based systems that are "safe for passengers and the environment." For Zaelke, however, HFO-1234yf has potential to be a widespread "high-value refrigerant."
The brainchild of chemical manufacturer Honeywell, HFO-1234yf was developed in response to policy initiatives in the European Union.
EU Drives Market, Will Montreal Protocol Follow?
The EU blew open the market for greener coolants in 2006, when it passed its Mobile Air Conditioning Directive, prompting chemical gas manufacturers like Honeywell and DuPont to find climate friendly alternatives to cool off people in their cars.