evidence: "Wind beats coal by any environmental measure, but that doesn't mean that its impacts are negligible," says senior author David Keith, an engineering and public policy professor at Harvard University. "We must quickly transition away from fossil fuels to stop carbon emissions. In doing so, we must make choices between various low-carbon technologies, all of which have some social and environmental impacts." "Wind turbines generate electricity but also alter the atmospheric flow," says first author Lee Miller. "Those effects redistribute heat and moisture in the atmosphere, which impacts climate. We attempted to model these effects on a continental scale." [...] "The direct climate impacts of wind power are instant, while the benefits accumulate slowly," says Keith. "If your perspective is the next 10 years, wind power actually has -- in some respects -- more climate impact than coal or gas. If your perspective is the next thousand years, then wind power is enormously cleaner than coal or gas."