Climate change - impacts on human and ecological health in Germany

of life-supporting processes. Climate and weather have always had a powerful impact on human

health and well-being. But like other large natural systems, the global climate system is coming un-

der pressure from human activities. Global climate change is, therefore, a newer challenge to ongo-

ing efforts to protect human health.

This essay examines the mentioned connectedness of human behaviour and the natural

world. More specifically, it deals with the global issue of human induced climate change

and its impacts on ecological health (? 3) and human health (? 4), focusing on Germany.

Following on from this, global and German mitigation policies are introduced and the

health benefits are outlined (? 5). The starting point marks a brief discussion of the link

between greenhouse gases and climate change (? 2).

In connection with the issues of the 'greenhouse effect' and 'climate change', stratospheric

ozone depletion is often also discussed. Undoubtedly, stratospheric ozone depletion has

impacts on ecological and human health, however it is left out of consideration in this es-

say due to the word limit, and to the complexity of its relationship to the greenhouse effect

and climate change.

2 The Greenhouse effect and climate change

On earth, human life would be not possible without a natural greenhouse effect. Green-

house gases let unhindered pass the entering short-wave sun radiation. At the same time

however, they prevent part of the long-wave radiation getting back into the universe

through absorption. Due to this, on earth is at an average temperature of 15°C, otherwise

it would be an inhospitable minus 18°C.

The climate change is, above all, a consequence of the growing greenhouse effect. The aca-

demic community assumes that the increasing emission of greenhouse gases by humans re-

sults in an increase of the average world temperature from 1990 to 2100 of 1.4 to 5.8 °C. 2

The main 'natural' greenhouse gases are CO2, H2O,, CH4, N 20, and O 3 . Since 1940, humans

have produced industrial greenhouse gases like CFC's, HCFs, HCFC's, PCFs, and SF 6 .

The impact of each single gas on the greenhouse effect is different. CO2 contributes the

most to the anthropogenic greenhouse effect. Humans burden the environment with CO2

through heating, electricity, and mobility. However, some emit more than others. Each

German emits annually 10 tons of CO2, a citizen of the US double that amount and an In-

dian just a tenth. 3

2 Treber et al. 2001, p.5/8.

3 IEA 2002, p.50f.

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The amount of greenhouse gases is just circa one per cent of the total atmosphere, how- ever its influence on temperature is decisive. An increase of its concentration in the at- mosphere changes the global climate.

3 Climate change impacts on ecological health

3.1 Impacts on ecosystems

3.1.1 Temperature, precipitation, and carbon dioxide

Temperature The prognosticated warming of the earth's atmosphere varies between 1.5 to 5 degrees. 4 This jump in temperature is comparable with the temperature difference between the Ice Age 18000 years ago and the current warm period. The serious difference is that the anthropogenically induced change in climate will occur much faster. 5 Due to the fast changes, all parts of nature's household will be affected, particularly aquatic and ter- restric ecosystems. The latter displays a complicated interacting system between abiotic (climate and soil) and biotic components (plants, animals, micro organisms). The climate represents the most important abiotic component. Temperature, that counts for the most important of climatic ele- ments, determines a multitude of life processes for animals and plants (metabolism, reproduction, mobility, behaviour, vernalisation, flowering time, ripeness of fruit and seed, …). Moreover, raised temperatures lead to an increase in soil activity and mineralization. The resulting release of nutrients makes an increase in biomass production possible. 6 The statements about the future distribution of precipitation in Europe are made with great uncertainty. On average, for Middle Europe warmer, dryer summers, and milder, wetter winters are expected. 7 Precipitation Already little changes in amount, setting in, and intensity of precipitation can disturb a regional water regime. For lots of plant species, precipitation and humidity of the soil are more im- portant than temperature. With the exception of the timberline that has temperature as a limited factor, precipitation plays often the crucial role in the distribution of plant species. Still, temperature and precipitation can combine as stress factors.

4 IPCC 2001b, p.13.

5 Deutscher Bundestag 1994.

6 Chapin et al. 1993, Kesel 2000.

7 Barrow 1993.

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Climate change affects the water household in ecosystems directly through changes in pre- cipitation, flowing off, soil humidity, snow coverage, snow melting, and evaporation; and indirectly through changes in the water level of inland waters by which the ground water level is affected. 8 Carbon dioxide Since the beginning of industrialisation, the global CO2 concentration has increased from 280 ppm to over 350 ppm and increases annually about 1,5 ppm (0,4%). 9 Increasing concentrations can have an indirect effect on ecosystems in terms of structure, population dynamics, competition relation- ships as well as forming of humus and nutrition turnover rates. 10 In terms of direct effects, there is a rise in photosynthesis rate and biomass production, an acceleration of growing, development, and aging, as well as a reduction in the opening of the stomata leading to a reduction in the transpira- tion rate. 11

3.1.2 Shift of the vegetation zones

Due to the shift of climatic zones, there will be also a shift in vegetation zones. Such a development places high demands on the adaptation abilities of animals and plants. Depending on the adaptation ability of the single species and the option of migration as a reaction to changing environmental cir- cumstances, the spatial distribution and composition of the living communities alter. It is assumed that for a multitude of ecosystems and their living communities an adaptation to the fast changing climatic conditions (that dragged on over millennia in the past) will not be possible. It is supposed that an increase in temperature of 1 degree will lead to a shift of the vegetation zones, in the direc- tion of the poles, of about 200-300 km. 12 Because single plant species have different paces in migra- tion, a splitting up of present species communities will occur. Less 'mobile' animal and plant species will be particularly affected.

3.1.3 Composition of species and biodiversity

Species with little ability to adapt (German: stenök) are particularly sensitive to the climatically caused new living and competition conditions. Hence, mountain, alpine, polar, as well as island and coastal communities, are especially in danger. 13 For Germany, this means the (at least local) loss of Nordic species as well as glacial relicts. On the other hand, there will be a spread of animal and plant species that are sensitive to frost or prefer warmth respectively. This might be in expansion in

8 Deutscher Bundestag 1994.

9 Enquete-Kommission 1992.

10 O´Neill 1994.

11 Bazzaz & Fajer 1992.

12 Enquete-Kommission 1992.

13 Tegart et al. 1990.

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