Geoscience Reference
In-Depth Information
Additionally, if someone is not in perfect health, they are counted
as having a disability and this enters into the DALY calculation. For
example, if someone goes blind from river blindness (onchocerciasis to
doctors), this syndrome would be equivalent to 62 percent of a death.
Deafness is counted as one-third of a death. The methods are highly
controversial even though the general idea of trying to avoid death and
illness is sound.
The techniques used to estimate the impact of climate change on
human health are challenging and not without criticism. Therefore I pro-
vide a detailed look at the estimates, particularly for diarrheal diseases.
This section is more technical than most others and can be skipped by
the reader who wishes to get the broad picture, but it will provide back-
ground on the analytical diffi culties for those interested in the details.
There are currently no global studies of the impact of climate change
on diarrheal diseases, so the team had to put together its own methods.
The study assumed that there were no adverse impacts on countries
with per capita incomes more than $6,000 per year. It then assumed
that the incidence of diarrheal diseases in low-income countries would
increase either 10 percent per °C increase for the high estimate or 0 per-
cent response as the low estimate. These estimates were based on lim-
ited studies in Peru and Fiji, but more general studies were not available.
Moreover, the studies assumed that, under this threshold, improve-
ments in income and health technologies did not lower the vulnerability
of people to these diseases.
Table 3 shows a simplifi ed set of results for the health losses from
climate change in the mid-twenty-fi rst century using relative risk esti-
mates of the WHO team. They estimated the loss in DALYs (disability-
adjusted life years) from climate change, here shown for two different
regions. Note that this estimate is the upper-bound of health impacts.
For this table, we have shown only two regions, Africa and high-income
countries. I show these two regions because these are at the extreme
ends of the estimated impacts and allow an assessment of the overall
impacts and trends.
7
The top part of Table 3 shows the estimated DALYs lost due to each
of the three most important diseases. The fi rst row refers to Africa. For
