In several of the past few posts, I’ve written about global warming by calling attention to recent publications by Elizabeth Kolbert and Al Gore. In there view, the evidence is all around us and we need to take notice of its effects: increased rainfall in some areas (the North Eastern part of the U.S.), widening ranges of butterflies, increased melting of glaciers, surges in intense hurricanes. And now comes the reaffirmation that global warming may be causing a rise in the symptoms of allergies.

In a report, Sara Goudarzi writing in LiveScience says that allergens are becoming more abundant because of climate change. In one study she reviewed, plants are flowering significantly earlier over time and advancing the season by about 0.8 days per year.

In studies at Harvard, researchers investigated the affects of ragweed growth in climate-controlled greenhouses. They studied ragweed growth at carbon dioxide levels of 350 parts (current figure), and 700 parts (expected future value) per million parts of air. One researcher said that “Plants grow larger and use water more efficiently when exposed to higher levels of carbon dioxide. Because of this, some people believe increasing levels may be a good thing, resulting in better crops and a greener planet.”

However, based on their findings, we can expect that pollen production will increase, and significantly so, there by creating greater health problems.