Particles from car exhausts generate more persistent and longer-lasting clouds but – paradoxically – less rain, new research suggests. Furthermore, putting more of these particles into the atmosphere reduces the low-level winds, which could reduce the amount of wind power available in very polluted regions.

The result is that arid but populated regions could suffer a triple blow as a result of vehicle pollution: less water, less hydropower and less wind energy. The US state of California is a prime example. It is home to many of the biggest cities in the US, has tens of millions of cars, has suffered energy cuts and drought, and relies on wind power for 1.5% of its energy.

http://environment.newscientist.com/article.ns?id=dn11017

[Negative thinking sucks. Think of the positive: polluted air enhances your lungs to take air more efficiently.]