Transcript Human Health

Impacts of global
climate change on
human health
Simon Hales
Wellington School of Medicine,
Wellington, New Zealand
Readings
• Many high quality reports and journal
articles are available online
• Some resources for researchers are also
available, including climate data and
scenarios
Overview
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What is climate change?
What are the relevant health issues?
What factors affect vulnerability?
What options are available for
adaptation?
Global climate change
Destabilization of the Earth’s climate due
to altered composition of the atmosphere
(increased concentrations of “greenhouse”
gases such as CO2)
Greenhouse gases trap solar radiation
leading to global warming
Likely effects of
climate change
 a rise in sea level of about 50cm by 2100
 A progressive increase in temperatures; an
increased occurrence of very hot days, and a
decrease in very cold days
 an intensification of the global hydrological
cycle, with altered global patterns of floods
and droughts
Main types of potential
health impact of global
climate change
• direct effects (relatively easy to assess)
• indirect effects (more difficult to assess,
but expected to predominate)
Direct effects
• sea-level rise, with population
displacement and damage to
infrastructure
• altered frequency of extreme events
(deaths, injuries, psychological disorders)
• exposure to thermal extremes (altered
rates of heat and cold-related illness and
death)
Indirect effects
• altered local ecology of water-borne
and food-borne infective agents
• altered food production due to
changes in climate, weather events,
and associated diseases
• effects on the range and activity of
vectors and infective parasites
• social, economic and demographic
dislocations due to adverse
climate change impacts on
economy, infrastructure, and
resources
IPCC’s conclusion
• “climate change is likely to have
wide-ranging and mostly adverse
impacts on human health, with
significant loss of life” (IPCC,
1996)
Some complexities...
• Interdependence of climate change
with other global issues
• Complex mechanisms and feedbacks at
local, regional and global scales
Some key implications
• Human health is an “integrating” outcome
of climate impacts
• Impacts will be strongly dependent on nonclimate factors (upon local and regional
context or “vulnerability”)
• Impacts might be greatly lessened by
effective adaptations which reduce
vulnerability
Determinants of
vulnerability
• Poverty and inequality
• Resources: technical, economic,
community, natural resources
• Population trends: growth,
urbanisation, migration
“Cross-sectoral” measures
Public policies to reduce vulnerability,
including promotion of social equity
within and between countries;
rescheduling or cancellation of foreign
debt; alteration of trade rules
“Public health” measures
Improved surveillance of disease
incidence and vector populations;
vector control measures; epidemic
warnings; possibly quarantine
measures; improved public health
infrastructure
“Inter-sectoral” adaptation
measures
(outside the health sector): early
warning systems; planning of human
settlements; disaster preparedness
programmes; civil engineering
planning; safe water supplies; waste
management; sanitation
Summary
• Many “no regrets” measures are
possible
• These would address current health
problems in the short term
• In the long term, successful adaptation
to climate change requires ecologically
sustainable development