Geoscience Reference
In-Depth Information
AIDS epidemic, which has lowered life expectancies by 20 years in the
worst-hit areas. 9
The health risks from climate change shown in Table 3 can be eval-
uated in the context of the overall health improvements in developing
countries. Take sub-Saharan Africa as an example. For this region, life
expectancy has increased about 10 years over the last four decades. The
upper-bound health losses from climate change shown in Table 3 are
about 1 year of life expectancy per person over the next four decades.
This implies that the health risks from climate change are equivalent to
a loss in health improvements of about four years at historical rates. In
other regions, the losses are estimated to be much smaller. 10 Moreover,
as I discuss in the next section, these health impacts refl ect unrealistic
assumptions and are likely to be exaggerated.
ADAPTATION AND MITIGATING FACTORS
The numbers in Table 3 are likely to overestimate the health im-
pacts because they do not take into account technological improve-
ments in health along with rising incomes. To begin with, they assume
minimal adaptations to increasing temperatures and the associated
health burdens. For example, we expect that people would adapt their
structures and lifestyles to the higher temperatures through such means
as air conditioning as their incomes rose. You might think this is a mixed
blessing.
A story on the dramatic growth in the use of air conditioning in
India pointed to the growth of electricity demand and CO 2 emissions
resulting from powering the air conditioners. This growing demand for
energy is indeed a central factor in the growth of CO 2 emissions and the
rapid warming in the scenarios analyzed above. At the same time, we
should not forget that air conditioning promotes human welfare—it cools
the homes of people in the hot regions of rapidly growing countries like
India and China, making them healthier and more productive.
However, the WHO analysis assumed no adaptation at all to heat
stress. Similarly, no adaptations were made to combat the potential spread
of malaria with warming, despite the wider array of adaptive options
that would be available with higher incomes. Additionally, the projec-
 
Search WWH ::




Custom Search