[Grad-postdoc-assn] Fwd: News Alert: Mon Jan 26
Maura Hagan
hagan at ucar.edu
Mon Jan 26 09:08:38 MST 2009
NCAR Fellows-
FYI, I'm appending this interesting article which includes a quote
from
Mark Flanner. Best regards.
--Maura
Begin forwarded message:
>
> The Other Global Warming
> 01/25/2009
> Boston Globe
> Venkataraman, Bina
>
> Return to Top
> Even if we contain the greenhouse effect, says a Tufts
> astrophysicist, we'll have another heat problem on our hands
>
> Human civilization will heat up the planet; the glaciers will melt
> and the seas will rise. It's a familiar refrain by now, with a
> familiar solution: stop pumping out the greenhouse gases that trap
> the sun's heat.
>
> But even if we bring the greenhouse effect under control, says a
> Tufts astrophysicist, the earth will warm up anyway, thanks to a
> completely different source of heat that we create ourselves.
>
> Over the next 250 years, calculates Eric J. Chaisson in a recent
> paper, the earth's population will start generating so much of its
> own heat - chiefly wasted from energy use - that it will warm the
> earth even without a rise in greenhouse gases. The only way to avoid
> it, he says, is to rethink how we generate energy.
>
> His paper examines the planet's growing pool of waste heat, a
> widespread phenomenon that nonetheless has been little studied as a
> cause of climate change. Nearly everything that uses or generates
> energy - chiefly power plants, but also cars, snowblowers,
> computers, and light bulbs - squanders some energy as wasted heat.
> And the larger and more energy-hungry the human population grows,
> the more waste heat remains in our atmosphere.'What this means for
> humans is that this is the ultimate limit to growth,' said Dennis
> Bushnell, the chief scientist at NASA's Langley Research Center, who
> urged Chaisson to publish his idea. 'As we produce more kilowatts,
> we have to produce more waste heat.'Chaisson's prediction suggests
> we need to change our energy policy - not just by keeping emissions
> low, but by shifting toward power sources that don't add new heat to
> the earth's system.
>
> The culprits in the waste-heat problem are not only dirty fossil
> fuels like coal and oil, but also some 'clean' power sources like
> nuclear and geothermal energy, which still add to the problem by
> pumping new heat into the atmosphere. The only way to stop waste
> heat-induced global warming, in Chaisson's view, is to rely on
> energy that already reaches the earth's surface: sunlight, and the
> wind and the waves that it powers.
>
> Critics say Chaisson's paper describes a scenario so far in the
> future, and so dependent on projections, that there's simply no way
> to know if it will come to pass. They also say it could distract us
> from the far more urgent problem of greenhouse gases. But the idea
> has piqued the interest of several scientists from around the world
> who see an opportunity to avert a crisis before future generations
> have to face it. And in a broader sense, it also suggests a new
> framework for decisions, one that appreciates the long road we - and
> our planet - have traveled in our evolution from the microbes of the
> primordial oceans and the stardust of the cosmos.
>
> That kind of long-range thinking is exactly what drew Chaisson's
> attention from astrophysics to the topic of global warming. His
> research typically focuses on the origins and evolution of stars and
> galaxies, and during a seminar on climate change in 2007, Chaisson
> asked himself: If we look at the earth as a spinning ball in space,
> reliant on the Sun, but where people plow new energy sources, how
> long will it be before all that new energy heats the planet up? He
> scribbled out some rough calculations to predict the eventual
> explosion of waste heat.
>
> The concept was not entirely new to him. With his mentor and friend,
> the late astronomer Carl Sagan, Chaisson had often discussed the
> notion that no civilization on any planet could survive over the
> long term unless it relied on energy from 'its parent star.''It just
> came as a no-brainer,' he said, of the waste heat idea.
>
> Chaisson published his paper last year in a journal of the American
> Geophysical Union. Since then, he has received a flurry of e-mails
> from intrigued researchers and has spoken about it at conferences
> from the West Coast to Europe.
>
> His predictions are based on a simple but fundamental law of
> science: Energy can't be perfectly harnessed, but tends to
> dissipate, usually in the form of heat. The concept, also known as
> entropy, is laid out in the inviolable second law of thermodynamics.
>
> In practice, this means that any machine we run, whether a car
> engine or a power plant, not only does the work we're asking it to
> do, but emits heat - a lot of heat. Think of touching a lightbulb,
> or holding your hand over your exhaust pipe after your car has been
> running for only a few minutes. The heat you feel is energy
> radiating uselessly into the air. On a much larger scale, the same
> thing happens when we burn coal or oil, run a nuclear plant, even
> bring geothermal energy up from beneath the earth's surface.
>
> Altogether, humans waste about two-thirds of the energy we produce
> on earth. More than half of the energy it takes to run a car's
> engine, for example, is squandered as waste heat, most of which
> pours out of exhaust pipes. Power plants regularly release more
> energy in waste heat that they make in electricity. Currently, all
> this heat makes little difference for our climate: it mostly
> dissipates into space. But the more energy humans use to fuel our
> societies and to feed our populations, the more waste heat we will
> emit. Eventually, as more economies industrialize, and as the
> population grows, that heat will become a significant problem.
>
> Even if we capped all greenhouse gas pollution, Chaisson calculated,
> in roughly 300 years the planet will warm at least 3 degrees
> Celsius, if our non-renewable energy use increases in line with
> historical trends and UN projections of population growth. Though 3
> degrees might sound small, such a rise in average global
> temperatures would lead to dire consequences, including significant
> sea level rise and mass extinction of species, according to
> scenarios outlined by the Intergovernmental Panel on Climate Change.
>
> The impact of waste heat from power plants, cars, and factories can
> already be measured in certain ways. The lakes, rivers, and oceans
> around nuclear power plants heat up as the water used to cool
> reactors is discharged into them. And waste heat contributes to
> 'heat islands' in cities. A 2007 study of Tokyo showed that summer
> temperatures in neighborhoods with office buildings are warmer by
> nearly 2 degrees Celsius when air conditioning units are running -
> because as the units cool the insides of buildings, they also pump
> heat into the air.
>
> The only way to stop this wasted heat from warming our atmosphere is
> to avoid generating it in the first place, which means using the
> energy that naturally comes to the planet. When a wind or wave
> turbine spins, or a solar panel collects rays, they're using energy
> that's already part of the system.
>
> Today, many climate scientists view waste heat as a negligible
> problem compared to greenhouse gas emissions. The heat-trapping
> effect of greenhouse gases has 100 times the effect on global
> warming that waste heat does, said Mark Flanner, a researcher at the
> National Center for Atmospheric Research in Boulder, Colo., who uses
> computer models to simulate waste heat. Flanner agrees with
> Chaisson, however, that it will play a much larger role over the
> long term.'If we assume the current growth in nonrenewable energy
> use, the heat flux will be of equal magnitude to the greenhouse
> effect 200 years from now,' he said.Still there are several big
> unknowns in Chaisson's predictions. One is his assumption that power
> plants and engines will continue to be quite wasteful. History
> suggests that societies tend to become more, not less, energy-
> efficient as technologies improve. Today's machines are far more
> efficient than yesterday's, and if that trend continues, the problem
> of global waste heat could be slower to develop - although the laws
> of thermodynamics say it's impossible to reduce wasted energy to
> zero.'We just don't know if there is a point at which energy use
> will level off,' said Yangyang Liu, an atmospheric scientist at
> Brookhaven National Laboratory who was intrigued by Chaisson's
> paper, but thinks it may overestimate waste heat's contribution to
> long-term global warming. 'The efficiency to convert energy to work
> will also probably improve over time.'Also uncertain is how much
> waste heat the planet's oceans can absorb before the overall
> temperature rises. And Chaisson's starkest scenarios assume that the
> human population will grow at certain rates, although it could drop
> sharply from widespread disaster or disease.
>
> Since his paper was published in July, the most frequent criticism
> Chaisson has heard is that the waste-heat problem diverts attention
> from the far more urgent question of how to tackle greenhouse gas
> emissions. If we cook ourselves with carbon dioxide first, critics
> say, waste heat will make little difference. 'I can't show that the
> estimates are wrong,' said John Merrill, an atmospheric physicist at
> the University of Rhode Island's Graduate School of Oceanography.
> 'But I can say that there are many hurdles caused by climate change
> and other environmental and social challenges that we need to
> address a lot sooner than this set.'Chaisson concedes that in
> looking 300 years into the future, not just 50 or 100, his critique
> sits outside current debates over climate change. But he warns that
> taking a long-term view is vital to human survival - even if the
> coming environmental catastrophe is something that neither we, nor
> our children, are likely to see in our lifetimes.'It's true, it's
> not important now,' he said, while sitting below a timeline of the
> universe in his office at Tufts. 'But from the point of view of an
> astrophysicist, we shouldn't be digging up any resources on our
> planet when we have plenty of energy coming from our parent star,
> the sun.'Long-range ideas like Chaisson's are uncommon in the realm
> of policy, where the pressure is great to deal with present-day
> challenges that affect people alive today. But such long-term
> thinking has been an important thread in the environmental movement,
> and holds an undeniable grip on the popular imagination. Rachel
> Carson's early and influential book 'Silent Spring' opened by
> imagining a future in which pesticides had killed all the songbirds.
> More recently, last summer's animated blockbuster 'Wall-E' set its
> story on a post-apocalyptic Earth, a wasteland heaped with trash.
>
> In the hope that thinking far, far ahead will catch on among
> scientists and policymakers, Chaisson has been spreading his
> perspective. Foundation for the Future, a Seattle-based nonprofit
> dedicated to contemplating the 'long-term future of humanity,'
> invited him to present at a meeting in Paris hosted by the United
> Nations Educational, Scientific, and Cultural Organization.
>
> Energy has been the key ingredient that has sustained human life,
> the growth of our intelligence and civilization, Chaisson told them.
> But the way we are making it could thwart our evolution, and our
> survival, if we do not adapt now. 'Humans are part of an evolving
> universe stretching across billions of light-years of space, and
> billions of years of time,' he said. Then he asked, 'Who are we to
> think that change ought now to stop?'Bina Venkataraman writes about
> science for the Globe.
>
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