Each morning recently I looked in the mirror to see if the rash on my shoulder had faded during the night. I was convinced that it was caused by a chigger bite that showed in a darker red. Apparently, I was wrong.

The rash didn’t fade and the nurse practitioner who looked at it ordered a Lyme disease test, which came back positive. The rash, the splotches he found elsewhere on my body and my recollection of an episode of chills added to the diagnosis. I’ve started taking an antibiotic and now I’m puzzling over when I might have had a deer tick bite and to what extent climate change had a hand in my malady.

The irony of this is that the diagnosis came on the same day the Environmental Protection Agency released its “Analysis of the Effects of Global Change on Human Health and Welfare and Human Systems.”

The Washington Post led its story about the report this way: “Climate change will pose ‘substantial’ threats to human health in the coming decades, the Environmental Protection Agency said yesterday — issuing its warnings about heat waves, hurricanes and pathogens just days after the agency declined to regulate the pollutants blamed for warming.”

The increase of vector-borne pathogens such as the one that causes Lyme disease was one of the effects cited in the report.

The next afternoon I drove slowly in traffic through water in the streets of La Crosse as the area had another of its severe storms. Here’s what the report had to say about that in its executive summary:

“In the future, with continued global warming, heat waves and heavy downpours are very likely to further increase in frequency and intensity.”

Gosh, doesn’t that sound like fun?

We’ll continue to learn more about these possible effects. For example, a weed ecologist with the U.S. Department of Agriculture recently said many weed species benefit more than food crops from a richer atmosphere of carbon dioxide, the main greenhouse gas, and research showed that more carbon dioxide made them less vulnerable to herbicides. We might yet learn to love dandelions, but allergy sufferers won’t like the additional pollen and more-potent poison in poison ivy.

And get this. Kudzu, the plant that ate the south, has crept into Illinois and could reach the upper peninsula of Michigan by 2015. That’s according to the same New York Times Magazine article that quoted the USDA official.

President George W. Bush pledged eight years ago in September that he would regulate carbon dioxide, a pledge that he reneged on a few months after he took office. So our nation has gone all these years without needed progress fighting climate change.

Climatologist James Hansen, who warned Congress 20 years ago about the dangers of climate change, now says, “We have used up all slack in the schedule for actions needed to defuse the global warming time bomb. The next president and Congress must define a course next year in which the United States exerts leadership commensurate with our responsibility for the present dangerous situation.”

Al Gore is right on his one-decade deadline for action. If we don’t get on it, climate change will bite us in ways more terrible than a tick.