Global investment in wind energy will reach the one trillion dollar mark by 2020. Right now, in Canada, the Canadian Wind Energy Association says it has 3,426 Megawatts of installed generating capacity.

But for many families, living near one or several of these giant wind turbines is an ordeal. In some cases, families have left their homes, driven out by the constant noise of these giant machines. The noise is both acoustical and sub-acoustical. In other words, some of it you can hear and some of it you cannot.

Doctors who have tried to treat those who complain of headaches, nausea, a constant feeling of unease, point to a chronic lack of deep sleep as the main cause.

Both the Canadian Wind Association and the American Wind Association have tried to demonstrate the safety of wind turbines. Doctors and wind energy opponents say their evidence is questionable. I have had many emails and talked to hundreds of people who insist these wind turbines are a health hazard.

The bottom line: there is no categorical proof of either the safety or the risks of living near wind turbines.

Here's how the Canadian Wind Energy Association described what it did to demonstrate wind energy safety. The document is carefully-worded:

"The American Wind Energy Association and the Canadian Wind Energy Associations (AWEA and CanWEA) established a scientific advisory panel in early 2009 to conduct a review of current literature available on the issue of perceived health effects of wind turbines."

Careful readers will note that no new field studies were conducted.

Here is the conclusion reached by the panel of doctors and scientists, as described by CanWEA:

"Following review, analysis, and discussion of current knowledge, the panel reached consensus on the following conclusions:

• There is no evidence that the audible or sub-audible sounds emitted by wind turbines have any direct adverse physiological effects.

• The ground-borne vibrations from wind turbines are too weak to be detected by, or to affect, humans.

• The sounds emitted by wind turbines are not unique. There is no reason to believe, based on the levels and frequencies of the sounds and the panel’s experience with sound exposures in occupational settings, that the sounds from wind turbines could plausibly have direct adverse health consequences."

Note again the careful language and several qualifiers.

The panel concluded that no specific studies involving people with adverse effects have been undertaken and none are necessary:

"In the area of wind turbine health effects, no case-control or cohort studies have been conducted as of this date. Accordingly, allegations of adverse health effects from wind turbines are as yet unproven. Panel members agree that the number and uncontrolled nature of existing case reports of adverse health effects alleged to be associated with wind turbines are insufficient to advocate for funding further studies."

So there you have it. Until governments get tough and order this additional testing, wind turbine development will continue at its current fast pace.

I'm all in favour of green energy. Save the planet. But do no harm in the process.