The Coming Health Crisis Indirect effects of global climate
change threaten the health of hundreds of millions of people.
The very uncertainty that shrouds this issue must serve as an
organizing principle for adaptation to its ill effects. Human
activity is disrupting Earth’s climate, and the rising emissions
of greenhouse gases are accelerating that disruption. (See “Our
Changing Climate” box below) Some of the health consequences of
climate change are straightforward: warmer temperatures, changes
in the hydrologic cycle, increased ground-level ozone, and
enhanced pollen production will increase exposure to heat
stress, alter patterns of infectious disease, and compromise air
quality. These and similar direct impacts of climate change have
been well covered in the scientific literature, and what we know
of their likely considerable effects is discussed in the sidebar
“1 Enormous uncertainties surround predictions regarding how
climate change may affect human well-being. Acknowledging these
uncertainties is a