Asthma and Allergies



The total number of asthma sufferers in the U.S. has more than doubled since 1980 and several exacerbating factors stem from burning fossil fuels.

Increased carbon dioxide (CO2) and warming both boost pollen production from fast-growing trees in the spring and ragweed in the fall. The allergenic proteins in the pollen become stronger with higher levels of CO2.

You may have observed that poison ivy is proliferating. Increased CO2 also stimulates poison ivy growth and boosts the chemical within it (uruschiol) that causes the contact dermatitis.

Small particulates from burning fossil fuels (e.g., diesel, coal), in addition to clogging our airways, attach to pollen and mold spores and help deliver them deep inside our lung sacs. Furthermore, ground-level ozone -- photochemical smog, chiefly from other tail pipe emissions -- injures the lung linings and primes the allergic response. The reaction that forms ozone also increases during heatwaves.

Meanwhile, climate change has extended the allergy and asthma season two to four weeks in the Northern Hemisphere (depending on latitude) since 1970. In addition to the anxious suffering induced by asthma, the loss of school days and lost productivity attributable to asthma in the U.S. cost us $56 billion in 2007 -- and that number continues to climb.



Spread of Infectious Diseases



Climate change encourages the spread of infectious diseases in two ways: Warming expands the geographic conditions conducive to transmission of vector-borne diseases (VBDs) while extreme events often leave clusters of mosquito-, water - and rodent-borne diseases (and spread toxins).

First, mosquito-borne diseases are appearing higher in the mountains of Africa, Asia, and Latin America, precisely where glaciers are retreating and plant communities are migrating upward. (Mountains are superb laboratories for studying climate change, because of their verticality. One can go from desert to tropical to polar conditions in just five miles.) Today, Malaria is circulating in the Nairobi, a mile high city; malaria has occurred high in the mountains of Bolivia; and dengue fever is spreading throughout the highlands of Vietnam.

In the U.S., tick-borne Lyme disease (LD) is the most important VBD. Its range is increasing as winters warm. LD case reports rose eight-fold in New Hampshire in the past decade and 10-fold in Maine (and today include all of its 16 counties). Babesiosis, or animal malaria, also carried by ticks, is growing in the northeast and threatens the blood supply.

Warmer winters and disproportionate warming toward the poles mean that the changes in range are occurring faster than models (based on average temperatures) projected. Biological responses of vectors and plants to warming are, in general, underestimated and may be seen as leading indicators of warming due to the disproportionate winter and high-latitude warming.