Climate change and pollination

Introduction. There is growing evidence to support an increase in air temperature over recent decades, with significant effects on aeroallergens such as pollen. It is generally accepted that the trend will continue, and become even more pronounced in the future. Background. - Global climate change is already affecting, and will continue to affect, with earlier floral initiation, the timing of the production of allergenic pollen. In addition, a warmer climate might lead to a longer pollen season and more days with high pollen counts. It could also increase the allergen content of pollens, and result in extension of plant species towards the poles and higher altitudes. Finally, rising levels of atmospheric CO2 are likely to reinforce these trends. Viewpoint. - These predictions are subject to uncertainties that may lead to outcomes that differ materially from what is expected. Understanding the magnitude and direction of the changes affecting potlinisation is critical in order to quantify the future allergic disease burden and model the impacts of different climate change scenarios. Conclusions. - Climate change influences the production, distribution, dispersion and allergenicity of anemophilous pollen and the growth and distribution of weeds, grasses and trees that produce it. These changes in aeroallergens and subsequent human exposure could affect the prevalence and severity of allergic disorders. There is, therefore, an important public health issue that requires development and implementation of appropriate response strategies without delay. (C) 2012 SPLF. Published by Elsevier Masson SAS. All rights reserved.