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

Air Pollution (Asthma & COPD)

A substantial body of research describes how increasing atmospheric temperatures, along with changes in vertical mixing height in the atmosphere, local weather patterns, wind speed and direction can worsen ground-level pollution, notably ozone.[7,37–39] Ground-level ozone exposures diminish lung function and increase acute premature mortality, asthma-related hospitalizations and emergency department visits.[7,37,40–42] For people with COPD, CVD, and diabetes, chronic ozone exposures also increase morality risks.[43] Temperatures have been projected to continue to rise through the end of this century, the extent depending upon the emissions scenario: by an additional 2–3.6C for a lower-emissions (B1) scenario, up to 4–6C for a current emissions growth, (A2) scenario (Figure 1).[4] This raises concerns about the ability to meet health-based air quality standards in the future. Recent studies suggest that by the year 2050, as many as 2,500 summertime deaths may be attributable to premature ozone-related mortality associated with climate change under a high-emissions (A1) scenario, absent other limits on ozone precursors.[44] Climate change can also lead to higher atmospheric concentrations fine particulates (PM2.5), although the effect of rising temperatures is more complex for the different chemical constituents of PM2.5.[45,46]

Figure 1.

Multi-model averages and assessed ranges for surface warming. Legend: Solid color lines are multi-model global averages of surface warming (relative to 1980–1999) for the scenarios A2, A1B and B1, shown as red, green, and blue (respectively), which are continuations of the 20th century simulations. Shading denotes the ±1 standard deviation range of individual model annual averages. The lower orange line is for the experiment where concentrations were held constant at year 2000 values. The grey bars at right indicate the best estimate (solid line within each bar) and the likely range assessed for the six SRES marker scenarios. The assessment of the best estimate and likely ranges in the grey bars includes the AOGCMs in the left part of the figure, as well as results from a hierarchy of independent models and observational constraints. Taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Figure SPM 5, Cambridge University Press.