Earth's winds have picked up again, after years of slowing

The wind picked up.

After Earth’s average surface winds speeds steadily declined for three straight decades beginning in the late 1970s, new research published Monday in the journal Nature Climate Change illustrates the winds have now recovered. The results, which show winds fell and then increased due to natural fluctuations in both the atmosphere and ocean, bodes well for the future of wind energy.

Previously, an explanation for the slowing of the planet’s low-altitude winds, dubbed “terrestrial stilling,” blamed human activity. The theory asserted that the construction of buildings, metropolitan areas, and fields of wind turbines themselves created an unnatural “roughness” on Earth's surface, which then dampened winds, explained Zhenzhong Zeng, a postdoctoral researcher at Princeton University and lead author of the study.

“This 'terrestrial stilling' has been considered a potential drag on the future of wind power,” said Zeng.

But wind instruments around the globe measured an uptick in average surface wind speeds beginning in 2010 (wind is inherently created by the sun unevenly heating different parts of Earth, resulting in masses of air with different temperatures and densities moving around the planet). Zeng and his team found the return of wind corresponded to changes in naturally occurring climate trends, such as the North Atlantic Oscillation (NAO), in which years-long changes in air pressure over the ocean drives weather trends over large parts of North America and Europe (for example, atmospheric shifts over the Atlantic Ocean drive more storms over Europe for years at a time).

“The longer-term impact is that we now have a credible explanation for the stilling and its reversal,” said John Dabiri, a professor at the California Institute of Technology who researches wind energy and fluid dynamics. “Concerns that the stilling was due to urbanization, or even due to wind farm development itself, appear to have been overblown,” noted Dabiri, who had no role in the study.

The results are also encouraging, Dabiri said, because they show that potential wind farms previously thought to be of only marginal quality — and thus not worth the investment — could indeed be productive wind farms since global stilling isn't a phenomenon that will worsen or persist indefinitely. Rather, it's a natural cycle.

The wind industry should (and almost certainly will) consider Earth’s natural fluctuations in wind speeds when determining where to build spinning turbines hundreds of feet in height and how large exactly the machines should be, Zeng said. (Taller wind turbines can capture faster winds higher in the air, but they cost more to build).

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Average wind speeds declined by about 8 percent over some three decades, before bouncing back. These numbers are important to know for planning how much energy a wind farm can produce, but they don't change the big picture, which is that wind energy can provide massive amounts of energy to the U.S. and elsewhere, said Charles Meneveau a professor of mechanical engineering at Johns Hopkins University. Meneveau also had no involvement in the research.

Wind has the potential to be an exceptionally dominant source of electricity, Meneveau emphasized “We could scale up wind power to provide over 50 percent of energy in the country,” he said, granted universities and research organizations invest in learning to build and operate fleets of wind farms across the nation.

Wind power has increased dramatically in the U.S. since around 2006. Over a decade ago, wind power provided less than 1 percent of electrical generation in the nation. Now, it's over 6.5 percent.

Some states, however, employ significantly more wind energy than the national average, thanks to ever-cheapening wind turbines and government incentives to build renewable sources energy, which produce no air pollution nor emissions of heat-trapping greenhouse gases.

California currently generates about 11.5 percent of its electricity from the Golden State's sprawling wind farms. Overall, renewables now comprise over 31 percent of the energy mix in California, the fifth-largest economy in the world.

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When it comes to generating power from wind, however, Texas takes the cake. Texas produces nearly 16 percent of its electricity from winds, according to the Department of Energy. What's more, during the first half of 2019, wind generated a whopping 22 percent of electricity in Texas, even out-competing coal, according to the Electric Reliability Council of Texas, a Texas power utility.

Wind, which is clearly plentiful on Earth, will play a critical role in transitioning economies and electrical generation away from gas, coal, and oil. Though a significant expansion in wind energy, enough to lower carbon emissions to avoid the worst consequences of climate change, will require heavy investment from both governments (like robust incentives to build wind farms) and private industry in the coming decade.

But, as John Hopkins' Meneveau stressed, wind energy is already significantly cheaper than the true cost of fossil fuels, if one accounts for the amassing damages and costs wrought by climate change and ever-worsening extremes in weather.

"If we were really paying for that now, wind [energy] would already be so much cheaper," said Meneveau.