climate change

global warming

If the world is going to avoid catastrophic climate change, we need to stop consuming fossil fuels and start getting power from renewable energy sources — including geothermal energy, biofuels, hydropower, solar farms, and wind — as soon as possible.

Wind is particularly appealing, as it's one of the cheapest and most efficient ways to generate electricity. But that doesn't mean wind power doesn't cause any potentially concerning side effects, according to a study published today in the journal Joule.

If we were to build enough wind plants to supply all the electricity used in the US — the power we use when we flick on a light switch or charge our phones, though not what's used to fuel cars or make steel — all those churning turbines would actually change the flow of the atmosphere above.

That heat redistribution could warm the regions near the wind farms by about .24 degrees Celsius. It's a significant amount.

In other words, generating power with wind still has effects on climate. But that doesn't mean it's causing climate change, according to Lee Miller, a postdoctoral fellow working with the Keith Group at Harvard and the coauthor of the new study, along with climate and geoengineering researcher David Keith.

This warming effect is a local effect, as Miller told Business Insider. That's different from the global warming and climate change caused by burning fossil fuels.

"Even with renewable technologies there are some climatic impacts," Miller said. Still, he said this is not a reason to stick with fossil fuels — and he fears that people who deny climate change could misuse the new study.

"I have no doubt that these results will be misconstrued and misinterpreted," he said.

Wind turbines would disturb the atmosphere, causing warming in some places and cooling in others. Maps are 3-year mean of perturbed minus 3-year mean of control for 2-m air temperatures, showing (A) entire period, (B) daytime, and (C) nighttime. The wind farm region is outlined in black, and, for reference, presently operational wind farms are shown as open circles in (A).

Wind versus coal — and why seeing the benefit could take some time

Right now, global temperatures are climbing because fossil fuel use pumps carbon dioxide and other greenhouse gases into the atmosphere. This modified atmosphere acts like a blanket, trapping more heat on the planet. As that process continues, scientists expect serious consequences, including the extinction of species, searing deadly heat waves, ocean acidification, more intense and rainy storms, and rising sea levels — all reasons to move away from fossil fuels.

For their new study, Miller and Keith used data collected from existing wind farms to design a model that assesses the effects of more wind power. To generate current US electricity needs, about one-sixth of all energy use in the US, Miller said we would need about 16 times the wind power we use now.

But putting wind farms in ideal places (as seen in the map above) and having them all running simultaneously would perturb the atmosphere above. The changes in circulation would lead to temperatures immediately overhead about .24 degrees C warmer. That's about 10 times the effect you'd see if you got that power from solar farms, the authors calculated.

Still, since these changes redistribute heat (not adding heat to the system like burning fossil fuels), other regions might see cooler temperatures on average.

The overall effects would be a mixture of good and bad.

In the wind farm region, the growing season might be extended by a couple of weeks, because nighttime freezes would be less likely. But pests might also start to emerge earlier and disappear later in the season. There might be more evaporation, but also more precipitation. And there could be ways to offset some changes too, like not running turbines as frequently at night, when they'd cause more warming.

"Even with renewable technologies, there are some climatic impacts. If we can understand those climatic impacts before deployment, maybe there's a way adjust them or amend them," said Milller. "Ideally we know as much about them beforehand, and then learn as we build out."

Turn all those turbines on immediately, and there are warmer temperatures. But over time, the benefits start to build. For every year people are drawing power from turbines instead of fossil fuels, less CO2 is pumped into the atmosphere. That has a long term benefit for future generations.

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Winds of controversy

The issue with publishing research like this is that fossil fuel interests might try to use it as evidence that switching to renewables isn't as urgent or important as the vast majority of experts think it is.

"It's a huge concern," said Miller.

His argument is that we should fully understand the positives and negatives of every source of energy we use, and that shouldn't take away from the understanding that moving away from fossil fuels needs to happen. That's not unlike scientists who believe that vaccines are safe, effective, and important, but still conduct controversial studies to try to improve them, sometimes highlighting side effects or weaknesses.

"All forms of energy have externalities, they have their pluses, they have their minuses," said Joshua Rhodes, a research fellow at the Energy Institute and the Webber Energy Group at the University of Texas at Austin. "We should look at strengths and weaknesses."

As Miller explains it, we need all the information we can get if we're going to make the transition to renewables work.

"Hitting these big renewable energy targets I think is going to be a lot more challenging than most people appreciate ... there's a lot to be learned as we head down that path," he said.