A stressed lemon tree, for example, will often produce a huge crop of tiny, very seedy lemons. This is simply lemon tree’s way of preparing for it’s own imminent demise and also it’s own legacy of possible seedlings. Another stress example: In daily pollen collections taken by biology professor Dr. Lee Parker and his students from top of Fisher Science Building at Cal Poly, San Luis Obispo, California, taken during middle of a severe seven year drought, all-time record oak pollen count levels were recorded. In past twenty years in particular there has been a huge increase in this planting of male cloned street trees. These trees can not produce pollen until they mature but with increases in CO2 levels, we can predict that they will mature earlier than expected. Shannon L. LaDeau, a researcher at Duke University found that pine trees grown with elevated levels of CO2 produced three times normal amount of seeds and also matured prematurely. Lewis H Ziska, Ph.D., a USDA researcher, recently found that increased CO2 resulted in huge increases in pollen production of ragweed and other weeds. David Karowe, a researcher at University of Michigan, found another interesting factor about increased CO2 levels and plants: their leaves contain fewer nutrients than normal. Nancy Tuchman, biology professor at Loyola University in Chicago, is also researching feed value of CO2 enhanced leaves on microorganisms and insects. She found that they all grow slower when fed these “enhanced” leaves. “If all plants are altered on a global level, then it’s certainly going to affect all organisms on Earth,” she said. “No one is going to escape.” Compounding all of this is that excessive burning of fossil fuels and resulting pollution may well be compromising our very endocrine and immune systems. Theo Colburn explored this well in very interesting book, “Our Stolen Future.” Great increases in already excessively high rates of urban pollen, combined with further compromised immune systems, may well be recipe for allergies of true epidemic proportions in not too distant future. Dr. Robert C. Stebbins, renowned biologist from UC Berkeley, told me recently in a phone conversation, that planting of all these cloned male dioecious and compromised monoecious trees, “is a classic example of how they just didn’t think about ecology involved.” If we don’t start paying closer attention to how we landscape our cities, and we don’t start getting serious about alternative clean energy sources, rampant allergies and other pollen-related illnesses may well be end result.

This article first appeared in New Scientist Magazine, in London.