“Mommy, will I always have asthma?” The sad-looking child with the inhaler stands against a smoggy skyline on the internet banner ad.  The ad then urges the reader to learn what he or she can do to combat, not asthma, but global warming. Sponsored by Environmental Defense and the Ad Council, the banner is part of a larger campaign launched in 2006 to “motivate Americans” to fight global warming.

This motivation, if necessary, should be based on some measure of reality. But is there really a connection between asthma and climate change?

It is true that asthma rates, particularly in children, are a significant concern. They have at least doubled in the last decade, and the death rates from asthma have also increased in recent years. The U.S. Food and Drug Administration estimates that asthma affects about 15 million Americans, including nearly 5 million children.

But during that same time, air quality improved. Monitoring data from the EPA indicate that air quality in the U.S. continues to improve. Since monitoring programs began, there have been significant reductions (ranging from nearly 30% to as much as 98%) in emissions of carbon monoxide, nitrogen dioxide, coarse particulate matter, sulfur dioxide, volatile organic compounds, and lead. Ozone emissions are at their lowest level.

That asthma rates are on the rise despite these gains suggests that there are other, more significant, asthma triggers.

The causes of asthma are somewhat elusive. Recent research suggest that a main cause may be problems with indoor air quality — tobacco, molds, dust mites, and cockroaches. Ironically, energy-saving efforts of the 1970’s designed to reduce excessive ventilation may have, in some cases, exacerbated indoor air quality problems, thus increasing the incidence of asthma.

On the other hand, a 2004 study of Wisconsin children indicated that cleaner air itself may be behind the increased asthma rates. The study found that children who lived on a farm, and in particular who were exposed to cattle manure and dust, had significantly lower rates of asthma and wheezing. Researchers suspect that early exposure to those types of things primes the immune system. An international study of asthma and allergies in children in 127 countries showed similar trends.

Given these results, the effects of climate change on asthma are hardly obvious or settled. The most likely link is that global warming may cause an increase in mold and pollen, which might cause an increase in asthma rates — but both of those relationships remain question marks.

Yet the Ad Council is not the only entity using asthma rates as a “motivator,” despite the lack of research supporting the sort of relationships they are claiming. In California, asthma rates were cited in the firing of Robert F. Sawyer, former head of the California Air Resources Board. "There are few environmental issues facing Californians that are more important to our children's health, our quality of life, and our economic security than air quality," Governor Arnold Schwarzenegger said in a statement. "When one out of six residents in the San Joaquin Valley has been diagnosed with asthma and one in five children carry an inhaler to school, it is a call to action."

Asthma is a legitimate health issue. But using it to promote an agenda without any significant scientific connection is a dirty trick.