Michelle Adamo, Portland, Ore.
A decade ago cars powered by fuel cells seemed like the future of green automotive travel, but many analysts now think otherwise.
These futuristic cars run on hydrogen fuel and emit only heat and water vapor. Their engines mix hydrogen, stored on-board in fuel tanks much like gas tanks, with oxygen in the air to produce electricity that powers the drive train. Environmentalists love the idea of fuel cell cars given their lack of greenhouse gas emissions and reliance on a renewable fuel that can be produced domestically.
Despite these benefits, fuel cell cars have not caught on and skeptics wonder if they ever will. One big hurdle is that creating hydrogen
fuel turns out to be highly inefficient compared to other readily available fuels. According to Richard Gilbert, co-author of Transport
Revolutions: Moving People and Freight Without Oil, the creation of hydrogen gas uses about half the energy it creates. Half of this
resulting energy then goes to the conversion of hydrogen back into electricity within fuel cells. The result is that “only a quarter of
the initially available energy reaches the electric motor.” In fact, hydrogen fuel cell vehicles’ efficiency varies between 18 and 20
percent, while battery electric vehicles have 77-80 percent efficiency.
Not only are fuel cells less efficient than internal combustion engines, their implementation on a wide scale would create enormous
infrastructure costs. New infrastructure would be required from “wells to wheels.” Also, fuel cell motors wear out five times faster than
internal combustion engines, thereby resulting in a shorter car life and more maintenance. Hydrogen’s small size and extreme reactivity
results in brittle metal and engines prone to leaking, which reduces both environmental and practical benefits.
But many still consider fuel cell cars a viable option. “Hydrogen is the key to sustainable transportation because it can be produced in
virtually unlimited quantities from renewable resources and because its use is nearly pollution-free,” says the non-profit INFORM. A
significant financial commitment to hydrogen research, says the group, could result in a variety of vehicles fueled by hydrogen that perform as well or better than gasoline vehicles, with a fraction of the environmental impact.
INFORM adds that transitioning to hydrogen could be achieved without new federal dollars if we reallocate funds within the national energy program from nuclear and fossil fuels. “The opportunities for innovation and economic growth in hydrogen energy are largely
untapped, and many nations are working to establish an early position in this fledgling field.” According to INFORM, Germany and Japan are far ahead of the U.S. in hydrogen development. The group would like to see U.S. policymakers encourage more development of fuel cells so we have options open in a fast-transitioning energy future.
Meanwhile, sales of battery electric and hybrid vehicles continue to soar — rising 228 percent in 2013 alone. There are currently no new
fuel cell vehicles for sale at American auto dealers, although Honda has hinted that it could have its FCX fuel cell engine ready for the
mass market by 2018.
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Dear EarthTalk: To what extent is Antarctica really melting and what impact might it have on coastlines around the world? — Andrea
Hutchinson, Cary, NC
The Antarctic continent, roughly the size of the United States and Mexico combined, is composed of rock covered by glaciers some 16,000 feet thick. The glaciers form from fallen snow compacting into successive layers of ice, and they eventually move downhill toward the coasts and “calve” into the ocean as icebergs and eventually melt out into the sea. Antarctica and Greenland combined hold about 99 percent of the globe’s freshwater ice.
According to the National Snow & Ice Data Center, the result of the entire Antarctic continent melting out completely would be sea level
rise of about 200 feet around the world, which could in turn lead to untold devastation. While no one can be sure how hot things will get
as a result of global warming, most climate models don’t forecast conditions hot enough to cause the wholesale melt-out of Antarctica.
In fact, the British Antarctic Survey (BAS) reports that the East Antarctic Ice Sheet, which constitutes about two-thirds of the world’s
southernmost and iciest continent, is remaining relatively stable, with some slight melting that is balanced out by new winter snows.
Because East Antarctica rests on rock that is higher than sea level, it is unlikely to collapse. In fact, East Antarctica’s ice cover may
thicken moving forward due to predicted increases in snowfall amounts over the coming decades.
But on the west side of Antarctica, ice across an area roughly the size of Texas called the Amundsen Sea Embayment (ASE) is already
thinning rapidly in large part as a result of surrounding waters warming up due to changing ocean circulation patterns. Many scientists
believe that these ocean changes are happening as a result of human-induced global warming as well as thinning of the stratospheric
“This is an area that has always caused glaciologists concern, because here the bedrock beneath the ice is a long way below sea-level and the ice is only kept in place because it is thick enough to rest on the bed,” reports BAS. “Thinning of the ice around the coast could lead to glacier acceleration and further thinning of the ice sheet.
Essentially, the ice sheet may be unstable, and the recent pattern of thinning could be a precursor to wholesale loss of the ASE ice sheet.”
Meanwhile, researchers from NASA and UC Irvine studying the ASE ice sheet report a “continuous and rapid retreat” of glaciers there and think that there is “no [major] obstacle that would prevent the glaciers from further retreat.” They worry that within a millennium
and perhaps as soon as two centuries, the ASE could melt out entirely—leading to between four and 10 feet of sea level rise around
the world—if moderate warming models prove to be correct.
Of course, we can all play a role in preventing such scenarios by reducing our carbon footprints. Take fewer airplane trips. Buy organic
food. Walk, bike or take public transit to work. If you must drive, get a hybrid or electric car. Wear a sweater instead of turning up the
heat. And urge legislators to push new laws that limit greenhouse gas emissions by industry, utilities and other big polluters. It may be
now or never.
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