Climate Change 2001:
Synthesis Report
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2.25

There are preliminary indications that some human systems have been affected by recent increases in floods and droughts. The rising socio-economic costs related to weather damage and to regional variations in climate suggest increasing vulnerability to climate change (see Table 2-1).

 
2.26 Extreme weather or climatic events cause substantial, and increasing, damage. Extreme events are currently a major source of climate-related impacts. For example, heavy losses of human life, property damage, and other environmental damages were recorded during the El Niño event of the years 1997-1998. The impacts of climatic extremes and variability are a major concern. Preliminary indications suggest that some social and economic systems have been affected by recent increases in floods and droughts, with increases in economic losses for catastrophic weather events. Because these systems are also affected by changes in socio-economic factors such as demographic shifts and land-use changes, quantifying the relative impacts of climate change (either anthropogenic or natural) and of socio-economic factors is difficult. For example, direct costs of global catastrophic weather-related losses, corrected for inflation, have risen an order of magnitude from the 1950s to the 1990s (see Figure 2-7), and costs for non-catastrophic weather events have grown similarly. The number of weather-related catastrophic events has risen three times faster than the number of non-weather-related events, despite generally enhanced disaster preparedness. Part of this observed upward trend in weather-related losses over the past 50 years is linked to socio-economic factors (e.g., population growth, increased wealth, urbanization in vulnerable areas), and part is linked to regional climatic factors (e.g., changes in precipitation, flooding events).

WGII TAR SPM & WGII TAR Sections 8.2 & 14.3
2.27 The fraction of weather-related losses covered by insurance varies considerably by region, and the uneven impacts of climatic hazards raise issues for development and equity. Insurers pay only 5% of total economic losses today in Asia and South America, 10% in Africa, and about 30% in Australia, Europe, and North and Central America. The fraction covered is typically much higher when just storm losses are considered, but flood-and crop-related losses have much lower coverage. The balance of the losses are absorbed by governments and affected individuals and organizations.

WGII TAR Sections 8.3.3.1 & 8.5.4
2.28 Climate-related health effects are observed. Many vector-, food-, and water-borne infectious diseases are known to be sensitive to changes in climatic conditions. Extensive experience makes clear that any increase in floods will increase the risk of drowning, diarrheal and respiratory diseases, water-contamination diseases, and -- in developing countries -- hunger and malnutrition (high confidence). Heat waves in Europe and North America are associated with a significant increase in urban mortality, but warmer wintertime temperatures also result in reduced wintertime mortality. In some cases health effects are clearly related to recent climate changes, such as in Sweden where tick-borne encephalitis incidence increased after milder winters and moved northward following the increased frequency of milder winters over the years 1980 to 1994.

WGII TAR SPM & WGII TAR Sections 9.5.1, 9.7.8, 10.2.4, & 13.2.5
2.29 The recognition and anticipation of adverse impacts of climate change has led to both public and governmental responses.

 
2.30 As a consequence of observed and anticipated climate change, socio-economic and policy responses have occurred in the last decade. These have included stimulation of the renewable energy market, development of energy-efficiency improvement programs enhanced by climate change concerns, integration of climate policies into broader national policies, carbon taxes in several countries, domestic greenhouse gases trading regimes in some countries, national and international voluntary agreements with industries to increase energy efficiency or otherwise decrease greenhouse gas emissions, creation of carbon exchange markets, public and political pressures for utilities to reduce or offset carbon emissions from new energy projects, industry reconnaissance into approaches to offset carbon emissions, and establishment of programs to assist the developing and least developed countries reduce vulnerabilities and adapt to climate change and engage in mitigation activities.

WGIII TAR Sections 3.2, 3.4-5, 3.8.4, 6.2.2, 6.3.2, & 9.2.1

Figure 2-7: The economic losses from catastrophic weather events have risen globally 10-fold (inflation-adjusted) from the 1950s to the 1990s, much faster than can be accounted for with simple inflation. The insured portion of these losses rose from a negligible level to about 23% in the 1990s. The total losses from small, non-catastrophic weather-related events (not included here) are similar. Part of this observed upward trend in weather-related disaster losses over the past 50 years is linked to socio-economic factors (e.g., population growth, increased wealth, urbanization in vulnerable areas), and part is linked to regional climatic factors (e.g., changes in precipitation, flooding events).

WGII TAR Figure 8-1


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