I recall the unintended consequences of forced use of ethanol (more toxic than regular gasoline) and the ban on DDT, the latter of which resulted in the loss of millions of lives lost to malaria. Wouldn’t it be prudent to avoid such disasters? [below are excerpts. Please see link for entire article]

Can large wind farms tweak weather downwind?

By Peter N. Spotts | 06.24.09

A battle over a wind farm in our backyard – off the island of Martha’s Vineyard – has shown that folks can raise a host of objections over unintended consequences, real or imagined.
They’ve included hazards to boaters, hazards to endangered migratory birds, hazards to aircraft flying between the Vineyard and the mainland, and of course, hazards to the property value of big-buck homes with scenic views of Nantucket Sound. Oh yes, one can’t forget the installation of transmission lines to link the turbines to the utility grid. And that’s just for one relatively small wind farm.
Now researchers are looking at another potential “unintended consequence” – the likelihood that collectively, groups of large wind farms in one region could alter weather patterns downwind of the turbines in another region.
So far, evidence suggests that large collections of wind farms could have small but measurable effects on atmospheric circulation patterns, cloudiness, and temperatures over substantial distances.
……. if the whole Midwest “is somewhat roughened over a large area, then you could imagine having a large-scale impact on the atmosphere.”
…….. he and his colleagues are trying to refine their estimates with an eye toward wind farms of the future – “how to design wind farms in ways that make them innocuous,” he says.
At first blush, the thought of vast collections of wind farms affecting weather patterns seems a bit far-fetched. But scientists have long studied the effects that changes in the roughness of Earth’s surface can have on low-level wind patterns. And large, regional collections of wind turbines would rough up the surface. In effect, it’s like planting very tall trees (roughly 300 feet high).
Last year, Mr. Kirk-Davidoff and a colleague, took a more detailed look to figure out how and why the climate changed. They found that the presence of rougher landscape over large areas introduced “appreciable” changes in wind, temperature, and cloudiness.
At the moment, Kirk-Davidoff acknowledges, the work is “pretty speculative.” Real-world measurements of wind farms’ effect on wind patterns are few and far between. In 2005, scientists in Europe published a study of the effects that large off-shore wind farms had on wind patterns, using satellite-based radar. But no one so far has built collections of wind farms on continental scales.
Yet “the possibility of relying heavily on wind power is not unreasonable,” he says – especially in light of wind-energy’s potential as outlined in the paper from the Proceedings of the National Academy of Sciences.
For Kirk-Davidoff, his work involves examining potential unintended consequences – at least the ones people can think up – “as the technology ramps up, so hopefully we don’t get into really surprising consequences before we have a chance to realize what they might be.”

http://features.csmonitor.com/environment/2009/06/24/can-large-wind-farms-tweak-weather-downwind/

Paul… you are absolutely wrong!..
“Finkel writes that Robert Gwadz, a malaria specialist at the US National Institutes of Health, says the worldwide ban on DDT that eventually followed the 1962 publication of Rachel Carson’s Silent Spring, which condemned use of the chemical, “may have killed 20 million children.” The quote by Gwadz does not include the huge number of adults that have also died since “DDT become nearly impossible to procure” because “the chemical was outlawed by most of the world for agricultural use”.

The deaths caused by malaria, however, are only the beginning of the problems caused by the disease. A far greater number of the continent’s people are regularly afflicted by malaria, which often causes life-l