Climate Change and Respiratory Health

Current Evidence and Knowledge Gaps

Tim K Takaro; Kim Knowlton; John R Balmes


Expert Rev Resp Med. 2013;7(4):349-361. 

In This Article

Changes in Pollen Releases (Asthma & Allergic Rhinitis)

Aero-allergenic plant pollen production is also affected by climate change. Laboratory and field studies in Europe, North America, Australia and Asia have shown that allergenic tree, grass, and weed pollen production increases several-fold under the influence of higher carbon dioxide (CO2) concentrations.[23,24] The combination of earlier spring onset and warmer summer temperatures that delay the first fall frost can extend pollen production seasons; in midwestern North America, ragweed-pollen production increased up to 27 days between 1995 to 2009, associated with rising temperatures.[25] Increases in ambient pollen concentrations are associated with higher rates of allergic sensitization, higher numbers of emergency department (ED) visits and hospital admissions for asthma and allergic rhinitis, as well as higher numbers of physician visits, and large increases in over-the-counter allergy medication sales.[7,8,26–31]