My reading of the article suggested that the authors of the study were
principally claiming that wind has an impact on climate, so it is already
being used. What wasn't clear from the article was *what type* of impact
reducing the energy level of winds all over the globe through the prolific
use of wind turbines might have. In a warming world, I understand we should
expect stronger winds. On a simplistic generalized level that might not be
relevant to local climate, slowing those stronger winds down might have
an ameliorating effect on climate change. Hence the claim that *The
magnitude of the changes was comparable to the changes to the climate caused
by doubling atmospheric concentrations of carbon dioxide* might not be as
bad as it is made to seem.
As usually, I'm grasping at straws, but as a layman, that's what stood out
for me.
Nando
On Sat, Apr 2, 2011 at 3:15 PM, Alvia Gaskill agask...@nc.rr.com wrote:
Wind and wave energy are the result of the conversion of solar energy
into kinetic energy, i.e. the motion of molecules. Once converted into
kinetic energy it's a use it or lose it proposition. Extracting kinetic
energy from the atmosphere or the ocean doesn't mean it won't be replaced by
more energy from sunlight. Planting more trees will also intercept winds,
albeit without the electricity generation. Who funded this research? The
same people who want to prevent contact with alien civilizations? I note
that the Royal Society was also a party to that one too. Note to Royal
Society. When you actually find something under the bed I should be afraid
of, wake me up.
- Original Message -
*From:* Andrew Lockley and...@andrewlockley.com
*To:* geoengineering geoengineering@googlegroups.com
*Sent:* Friday, April 01, 2011 8:10
*Subject:* [geo] Wind and wave energies are not renewable after all
Wind and wave energies are not renewable after all
- 30 March 2011 by *Mark
Buchanan*http://www.newscientist.com/search?rbauthors=Mark+Buchanan
- Magazine issue 2806 http://www.newscientist.com/issue/2806. *Subscribe
and save* http://www.newscientist.com/subscribe?promcode=nsarttop
- For similar stories, visit the *Energy and
Fuels*http://www.newscientist.com/topic/energy-fuels
and *Climate Change*http://www.newscientist.com/topic/climate-change
Topic
Guides
*Editorial: *The sun is our only truly renewable energy
sourcehttp://www.newscientist.com/article/mg21028062.500-the-sun-is-our-only-truly-renewable-energy-source.html
*Build enough wind farms to replace fossil fuels and we could do as much
damage to the climate as greenhouse global warming*
WITNESS a howling gale or an ocean storm, and it's hard to believe that
humans could make a dent in the awesome natural forces that created them.
Yet that is the provocative suggestion of one physicist who has done the
sums.
He concludes that it is a mistake to assume that energy sources like wind
and waves are truly renewable. Build enough wind farms to replace fossil
fuels, he says, and we could seriously deplete the energy available in the
atmosphere, with consequences as dire as severe climate change.
Axel Kleidon of the Max Planck Institute for Biogeochemistry in Jena,
Germany, says that efforts to satisfy a large proportion of our energy needs
from the wind and waves will sap a significant proportion of the usable
energy available from the sun. In effect, he says, we will be depleting
green energy sources. His logic rests on the laws of thermodynamics, which
point inescapably to the fact that only a fraction of the solar energy
reaching Earth can be exploited to generate energy we can use.
When energy from the sun reaches our atmosphere, some of it drives the
winds and ocean currents, and evaporates water from the ground, raising it
high into the air. Much of the rest is dissipated as heat, which we cannot
harness.
At present, humans use only about 1 part in 10,000 of the total energy that
comes to Earth from the sun. But this ratio is misleading, Kleidon says.
Instead, we should be looking at how much useful energy - called free
energy in the parlance of thermodynamics - is available from the global
system, and our impact on that.
Humans currently use energy at the rate of 47 terawatts (TW) or trillions
of watts, mostly by burning fossil fuels and harvesting farmed plants,
Kleidon calculates in a paper to be published in *Philosophical
Transactions of the Royal Society* http://arxiv.org/abs/1103.2014. This
corresponds to roughly 5 to 10 per cent of the free energy generated by the
global system.
It's hard to put a precise number on the fraction, he says, but we
certainly use more of the free energy than [is used by] all geological
processes. In other words, we have a greater effect on Earth's energy
balance than all the earthquakes, volcanoes and tectonic plate movements put
together.
Radical as his thesis sounds, it is being taken seriously
