America’s electric cars are better for the environment, but they share a dirty little secret.
The
Chevy Volt, Nissan Leaf and Tesla Roadster all use a super greenhouse
gas known as HFC 134a as the refrigerant for their air conditioners. The
liquid coolant is so potent that when it leaks into the atmosphere, it
traps 1,400 times more heat than carbon dioxide over a 100-year time
horizon.
For automakers and advocates of
green transportation, it poses an uncomfortable truth: Vehicles touted
as a solution to climate change carry a hairspray-sized canister loaded
with a chemical that significantly contributes to warming of the earth’s
climate. As much as half of current HFC emissions, a small but
fast-growing source of global warming pollution, come from leaks out of
the air conditioners in cars.
Already a
number of Chevrolet, Buick, GMC and Cadillac gas-powered cars use an
alternative climate-friendlier coolant called HFO 1234yf, as carmakers
confront growing pressure from environmentalists and as regulations are
developed by governments. Climate experts say it’s clear that all
electric automakers should get on board soon. “It makes sense for
electric vehicles to use (alternatives), and to reduce their overall
global warming potential,” said Don Anair, deputy director of the clean
vehicles program at the Union of Concerned Scientists, a science
advocacy group.
But among 16 EV models on America’s roads,
only two — Chevy’s newest model of its all-electric Spark and the
leasable Honda Fit — have ditched the super greenhouse gas HFC 134a for
the climate-safe alternative so far.
Many
automakers of both electric cars and conventional ones have expressed
reluctance to commit to the switch, citing the cost and limited supply
of new alternatives. The European Union has banned HFC 134a for any
newly redesigned or re-engineered vehicles this year, and for all
vehicles in 2017 — though the industry elsewhere is not rapidly adopting
the EU’s lead. The United States has no such mandate yet. The U.S.
Environmental Protection Agency is considering one.
How
countries got to this point is a classic case of unintended
environmental consequences. Under the Montreal Protocol, a 1987 treaty
that zeroed out substances harmful to the earth’s ozone layer, HFC 134
was chosen by nations as the best alternative at the time to replace
ozone-depleting CFCs. The result today is that most of the billion or so
cars on the world’s roads use the HFC refrigerant — but while the ozone
layer has rebounded, HFC 134a is exacerbating the global warming
problem.
So far, HFC 134a and other types
of hydrofluorocarbons have contributed to less than 1 percent of total
global warming, according to a study published in the Atmospheric
Chemistry and Physics scientific journal. But the use of these damaging
gases is climbing generally, as developing world economies use and
produce more HFC-spewing cars, air conditioners and refrigerators, and
as they make more foam insulation that uses the chemical during
manufacture.
Emissions from HFCs are
growing at a rate of 10 to 15 percent per year, the study says. Left
unchecked, HFCs alone could add up to 0.5 degree Celsius of the global
average temperature rise by the end of the century, about a quarter of
the 2 degree Celsius rise that nations are struggling to stay within
through international agreements.
Electric
vehicles are touted for producing zero tailpipe emissions and being a
critical force in reducing fossil fuel use and curbing climate-changing
pollution — which could make their use of the super greenhouse gas HFC
134a all the more hypocritical.
The Chevy
Volt, Nissan Leaf and Tesla Roadster represent about two-thirds of the
roughly 180,000 EVs sold in recent years in the United States.
Kevin
Kelly, a spokesman for General Motors, wouldn’t say if or when the
hybrid Chevy Volt, the biggest-selling U.S. EV, might switch to HFO
1234yf.
The auto
giant in 2010 said it would be the first U.S. carmaker to voluntarily
phase out HFC 134a from many of its passenger cars. So far, only its
Chevy Spark EV, which had sold 703 units as of February, and its
conventional Cadillac XTS luxury sedan use the new refrigerant. Kelly
declined to disclose which other GM models have or will soon follow
suit.
Spokespeople for Nissan Motors in the
United States were not immediately able to provide more information.
Tesla Motors did not respond to repeated requests for comments.
David
Doniger, a policy director at the Natural Resources Defense Council who
has worked on ozone issues since the 1980s, noted the hypocrisy, but
said he is “more concerned about getting the overall transition to occur
as quickly as we can.”
All car
manufacturers “have the opportunity to switch refrigerants, and they
should do it as quickly as they can,” he said. “From an environmental
point of view, if you want to get the changeover happening at a large
scale, I wouldn’t focus first on electric cars _ I’d just be focusing on
volume.” Nissan Motors, for instance, sold 1.2 million gas cars in the
U.S. in 2013 and just 23,000 all-electric Leafs.
Source;
No comments:
Post a Comment