Wind farms can affect local temperature - how the papers reported it
- 30 Apr 2012, 09:09
- Christian Hunt
Wind turbines might be affecting local weather and
temperature, according to
a new study in the Journal Nature Climate Change. But despite
researchers' assurances that these are localised effects, some UK
outlets have been suggesting this means wind farms are causing
Although getting detailed measurements of wind speed
is usually high on the list of priorities around wind farms, taking
the temperature around the turbines might seem more unusual. But
measuring the effects of wind farms on local temperatures may have
thrown up some interesting results.
Scientists examining temperature readings for an area in Texas
that contains a large wind farm have found a "warming trend of up
to 0.72◦ C per decade, particularly at night-time, over wind farms
relative to nearby non-wind-farm regions". According to the
researchers, the warming patterns they've observed closely match
the distribution of wind farms.
This appears to be the first time anyone has used satellite data
to measure the impacts of large wind farms on surface temperature.
The researchers compared temperatures in the two years before 2,358
turbines were constructed with a two-year period after they had all
been built. They noticed that after correcting for other causes of
warming, the temperature around the site had increased.
So what is it about the wind turbines that might be causing the
warming? The paper suggests it's probably due to higher wind speeds
at night - which mean the wind turbines are more active, and have a
bigger effect on their environment.
What effect is that? Changes in temperature are "very probably"
caused by changes in local windspeed and turbulence due to the
turbines, the researchers say. Modelling studies have already
suggested that wind farms can noticeably affect local weather. But
the authors of this paper are careful to point out that these
findings are still a bit sketchy and that understanding of the
exact way in which turbines interact with their environment is
still developing - you can read more on this in a
Q and A with them.
One of the researchers is Dr
Somnath Roy who led a previous study looking at the same effect
around a wind farm in California. Anti-wind outlets pounced on that
earlier paper, ignoring the work's focus on local effects to claim
it showed that wind farms
increase climate change - here in the Daily Mail:
"They have long been championed as a way
to combat global warming by creating clean energy.
"But wind farms can actually alter the climate according to a new
study by a group of American scientists.
"The team from the University of Illinois found that daytime
temperatures around wind farms can fall by as much as 4C, while at
night temperatures can increase."
As we noted when the
article came out the earlier research did conclude that wind
turbines lower temperatures in the region of the turbines a bit in
the day and raise it a bit at night by moving air around, it didn't
suggest that wind turbines were warming the planet up or otherwise
causing climate change.
In response, Roy told
My Proceedings of the National Academy of
Sciences paper is on local-scale processes where we find that
windfarms may make the nights warmer and days cooler in their
immediate vicinity. Climate change is a longer-term phenomenon
involving process that operate at larger spatial scales…My
expertise is in small-scale (what we call atmospheric boundary
layer and/or mesoscale) processes, not climate.
You might hope that this time around the distinction between
local weather effects and global climate change would be more
For the most part, the press have reported the study pretty
straightforwardly - with plenty of coverage apparently just based
on the press release.
Reuters writes that the study may "[cast] a shadow
over the long-term sustainability of wind power", but doesn't
The Daily Mail writes a fairly sane and sensible interpretation
of the study, giving it an accurate and normal headline in the
paper, and then climate sexes it up for an online
In print, the reasonably straightforward reporting of the paper
is titled: Wind farms link to rising temperatures
could have detrimental impact on wildlife and weather, say
scientists. Online, the headline is a punchier "Wind
farms make climate change WORSE: Turbines actually heat up local
areas". Strictly speaking it's accurate, but given the localised
nature of the effect also misleading.
Meanwhile, the front page of today's Telegraph carries a piece
entitled: "Wind farms linked to climate change". The online
headline is "
Wind farms can cause climate change, finds new study". It goes
on to say:
"Wind farms can cause climate change, according to new research
that shows for the first time the new technology is already pushing
Fox News, on the other hand, pulls no punches with: New research finds wind farms cause global
Has something changed since the last paper came out? And are the
researchers campaigning against new wind farms? Still no, although
they argue for better systems to measure how turbines might affect
different elements of local weather and climate systems. The
Guardian talked to one of the authors of the letter, who said:
... that his results could not be used
as an justification for blocking new wind farms. "The warming might
have positive effects," he said. "Furthermore, this study is
focused only on one region and for only 9 years. Much more work is
needed before we can draw any conclusion."
And is it possible to say wind farms cause climate change? The
authors say not:
"Overall, the warming effect reported in this study is local
and is small compared to the
strong background year-to-year land surface temperature changes.
Very likely, the wind turbines do not create a net warming of the
air and instead only re-distribute the air's heat near the surface,
which is fundamentally different from the large-scale warming
effect caused by increasing atmospheric concentrations of
*Updated on 30 April 2012 at 15.15 to include Q&A