The Intergovernmental Panel on Climate Change (IPCC) issued its “Fourth Assessment of Working Group II,” which updates past studies and sets forth the “current scientific understanding of impacts of climate change on natural, managed and human systems, the capacity of these systems to adapt and their vulnerability,” the IPCC said in a summary of its findings. “It builds upon past IPCC assessments and incorporates new knowledge gained since the Third Assessment.”
That report is ancient history. It was issued in 2001, when there were still many in the scientific community who still questioned the existence of a global warming trend and the seriousness of the impacts it might have. Six years later that’s no longer the case. No serious scientist today disputes the existence of global warming, even though its potential impact remains the subject of continued analysis.
The IPCC was unequivocal. It stated: “Observational evidence from all continents and most oceans shows that many natural systems are being affected by regional climate changes, particularly temperature increases.” The report cites the following examples – all of which are well documented with scientific studies:
— Changes in snow, ice and frozen ground (including permafrost);
— increased run-off and earlier spring peak discharge in many glacier- and snow-fed rivers;
— warming of lakes and rivers in many regions, with effects on thermal structure and water quality;
— earlier timing of spring events, such as leaf-unfolding, bird migration and egg-laying;
— poleward and upward shifts in ranges in plant and animal species;
— shifts in ranges and changes in algal, plankton and fish abundance in high-latitude oceans;
— increases in algal and zooplankton abundance in high-latitude and high-altitude lakes;
— range changes and earlier migrations of fish in rivers.
Under the category of “Other effects of regional climate changes on natural and human environments,” which are harder to gauge, a partial list of the IPCC’s report includes an analysis of the following:
— Effects on agricultural and forestry management at Northern Hemisphere higher latitudes, such as earlier spring planting of crops, and alterations in disturbance regimes of forests due to fires and pests;
— some aspects of human health, such as heat-related mortality in Europe, infectious disease vectors in some areas, and allergenic pollen in Northern Hemisphere high and mid-latitudes;
— some human activities in the Arctic (e.g., hunting and travel over snow and ice) and in lower elevation alpine areas (such as mountain sports);
— settlements in mountain regions are at enhanced risk to glacier lake outburst floods caused by melting glaciers. Governmental institutions in some places have begun to respond by building dams and drainage works;
— in the Sahelian region of Africa, warmer and drier conditions have led to a reduced length of growing season with detrimental effects on crops. In southern Africa, longer dry seasons and more uncertain rainfall are prompting adaptation measures;
— sea-level rise and human development are together contributing to losses of coastal wetlands and mangroves and increasing damage from coastal flooding in many areas.
The last observation should be of particular concern to the insurance industry, as it is in the front line as far as underwriting the ever increasing risks inherent in rising seal levels and coastal development. For a thoroug analysis of the impact climate change potentially has on the industry consult Lloyds ”360 Report,” which is detailed in the following article.
The IPCC also warns of the impact of a flood/drought scenario. “By mid-century, annual average river runoff and water availability are projected to increase by 10 to 40 percent at high latitudes and in some wet tropical areas.” But they are also expected to “decrease by 10 to 30 percent over some dry regions at mid-latitudes and in the dry tropics, some of which are presently ‘water stressed’ areas.” In sum: “Drought-affected areas will likely increase in extent. Heavy precipitation events, which are very likely to increase in frequency, will augment flood risk.”
The IPCC also documents the deleterious effects of carbon dioxide emissions. It warns that “over the course of this century net carbon uptake by terrestrial ecosystems is likely to peak before mid-century and then weaken or even reverse, thus amplifying climate change.” As a result “approximately 20 to30 percent of plant and animal species assessed so far are likely to be at increased risk of extinction if increases in global average temperature exceed 1.5°-2.5°C [2.7° to 4.5°F]. The changes will effect “ecosystem structure and function, species’ ecological interactions, and species’ geographic ranges, with predominantly negative consequences for biodiversity, and ecosystem goods and services e.g., water and food supply.”
The list goes on, and it’s not good news. For instance the IPCC predicts a growth in cases of malaria, the second biggest killer of young children after malnutrition/starvation, as the mosquitoes that carry the disease extend their range.
Africa is in fact the area in the world most vulnerable to climate change. Not only will the effects be more pronounced on the Continent, but it is also the least economically developed and consequently in the worst position to take remunerative measures.
In its analysis of the potential impact on North America the IPPC notes: “Moderate climate change in the early decades of the century is projected to increase aggregate yields of rainfed agriculture by 5 to 20 percent, but with important variability among regions.
“Major challenges are projected for crops that are near the warm end of their suitable range or depend on highly utilized water resources. Warming in western mountains is projected to cause decreased snow pack, more winter flooding, and reduced summer flows, exacerbating competition for over-allocated water resources.
“Disturbances from pests, diseases, and fire are projected to have increasing impacts on forests, with an extended period of high fire risk and large increases in area burned.
“Cities that currently experience heat waves are expected to be further challenged by an increased number, intensity and duration of heat waves during the course of the century, with potential for adverse health impacts. The growing number of the elderly population is most at risk.
“Coastal communities and habitats will be increasingly stressed by climate change impacts interacting with development and pollution. Population growth and the rising value of infrastructure in coastal areas increase vulnerability to climate variability and future climate change, with losses projected to increase if the intensity of tropical storms increases. Current adaptation is uneven and readiness for increased exposure is low.”
Although there will be some benefits accruing from the rise in global temperature – Europe had its mildest winter in recent memory – the overall effect of climate change is exactly what it says – Change is coming for all of us. If you want to understand it a bit more log on to the IPCC web site at: www.ipcc.ch. If you want to access the summary of the report go to: http://www.ipcc.ch/SPM6avr07.pdf.
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