The Impacts and Costs of Climate Change
The Third Assessment Report projects intensified droughts, associated with the likely increase in El
Nifio events in many different regions. The main impacts of drought will be decreased agricultural
and rangeland productivity and decreased hydro-power potential in drought-prone regions.
Decreased agricultural productivity resulting from drought will contribute to the proportion of
undernourished people, particularly in developing countries.
Although climate change scenarios indicate a further increase in the length of the growing season in
Europe, the potential increase in productivity will be limited by drought stress. Drought stress
increases when the water demand of the plants exceeds water availability.
Between 1975 and 2001, 238 flood events were recorded in Europe. Over this period the annual
number of flood events clearly increased. The number of people affected by floods rose significantly,
with adverse physical and psychological human health consequences26. With 2.0-6.40C temperature
increase the damage from riverine floods will be several times higher than in the no climate change
case. With 1.40C temperature increase coastal floods are projected to increase the number of people at
risk by 10 million, 3.20C will bring 80 million at risk.
Impacts from storm damage and extreme weather
Extreme weather events are also likely to increase, with heat waves, drought, floods, storms and
tropical cyclones. Changes in both frequency and severity are possible, though these may not be
linearly dependent on average climate.
In Europe, 64 % of all catastrophic events since 1980 are directly attributable to weather and climate
extremes: floods, storms and droughts / heat waves. 79 % of economic losses caused by catastrophic
events result from these weather and climate related events. Economic losses resulting from weather
and climate related events have increased significantly in the last 20 years, from an annual average of
less than USD 5 billion to about USD 11 billion. This is due to wealth increase and more frequent
events. Four out of the five years with the largest economic losses in this period have occurred since
1997. The average number of annual disastrous weather and climate related events in Europe doubled
over the 1990s compared with the previous decade, while non-climatic events such as earthquakes
remained stable. Climate change projections show an increasing likelihood of extreme weather events.
Thus, an escalation in damage caused is likely27.
Socially contingent effects
There is an emerging consensus that widespread climate change may increase socially contingent
effects28, due to multiple stresses coming together. This is unlikely to affect Europeans directly, but
may well have effects on Europe. The combination of stresses from climate change from the above
effects may converge on a number of vulnerable areas, for example in Africa, leading to potential
regional conflict, poverty or famine, migration, etc.
It is highlighted that the disproportionate impact of climate change occurs on developing countries
because these countries are more vulnerable to climate change than developed countries: their
economies rely more heavily on climate-sensitive activities; they are close to environmental tolerance
limits; and they are poorly prepared to adapt to climate change. In contrast, richer societies tend to be
better able to adapt and their economies are less dependent on climate. With the upper range of IPCC
projections of climate change, the impacts are likely to adversely affect achievement of the
26 Impacts of Europe's changing climate. An indicator-based assessment EEA Report No 2/2004
27 Impacts of Europe's changing climate. An indicator-based assessment EEA Report No 2/2004
28 We use classification of socially contingent damages to describe those large scale dynamics related to human values and
equity that are poorly represented in damage estimates based on cost values, e.g. regional conflict, poverty.
AEA Technology Environment, August 2005
Watkiss, Paul; Downing, Tom; Handley, Claire & Butterfield, Ruth. The Impacts and Costs of Climate Change. Oxford, England. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc29337/. Accessed May 4, 2015.