GIS, Environmental Modeling and Engineering by ALLAN BRIMICOMBE (original) (raw)

The ecological and economic consequences of Global Climate Change

Our planet has always experienced climate changes during its geological history, but because of the massive emission of greenhouse gasses, climate is now expected to change at unprecedented rate. Quite likely, neither ecological nor anthropological systems will have the time to straightforwardly adapt to the new conditions. What should we expect for the following years? Which will be the cost of the do-nothing alternative? Which will be the benefits and the costs of effectively implementing the Kyoto Protocol? In this paper we intend to briefly review the potential impacts of global climate change. Before actually addressing the issue of perspective impacts, the first section of this work is devoted to briefly addressing the two following questions: a) do we already have evidence of climate change with respect to only half a century ago? If so, are these changes to some extent induced by anthropogenic activities, specifically by Greenhouse Gasses (GHG) emissions by humans?; b) which are the predictions concerning future climate change? And which are the perspective consequences of these changes on physical and ecological systems? In the second part of this paper, we briefly review the economic consequences of climate changes deriving them under different assumptions and scenarios. Specifically, after a brief description of the economic methods commonly used to value the impacts of GHGs we present a cost-benefit analysis of the Kyoto Protocol. We then conclude by briefly reviewing other economic studies related to the reduction of GHGs emissions and the opportunities and the costs of carbon sequestration.

Confronting climate change: Avoiding the unmanageable and managing the unavoidable

Global climate change, driven largely by the combustion of fossil fuels and by deforestation, is a growing threat to human well-being in developing and industrialized nations alike. Significant harm from climate change is already occurring, and further damages are a certainty. The challenge now is to keep climate change from becoming a catastrophe. There is still a good chance of succeeding in this, and of doing so by means that create economic opportunities that are greater than the costs and that advance rather than impede other societal goals. But seizing this chance requires an immediate and major acceleration of efforts on two fronts: mitigation measures (such as reductions in emissions of greenhouse gases and black soot) to prevent the degree of climate change from becoming unmanageable; and adaptation measures (such as building dikes and adjusting agricultural practices) to reduce the harm from climate change that proves unavoidable. Avoiding the Unmanageable Human activities have changed the climate of the Earth, with significant impacts on ecosystems and human society, and the pace of change is increasing. The global-average surface temperature is now about 0.8°C above its level in 750, with most of the increase having occurred in the 20th century and the most rapid rise occurring since 970. Temperature changes over the continents have been greater than the global average and the changes over the continents at high latitudes have been greater still. The pattern of the observed changes matches closely what climate science predicts from the buildup in the atmospheric concentrations of carbon dioxide (CO 2), methane (CH 4), and other greenhouse gases (GHGs), taking into account other known influences on the temperature. The largest of all of the human and natural influences on climate over the past 250 years has been the increase in the atmospheric CO 2 concentration resulting from deforestation and fossil-fuel burning. The CO 2 emissions in recent decades (Figure ES.), which have been responsible for the largest part of this buildup, have come 75% to 85% from fossil fuels (largely in the industrialized countries) and 5% to 25% from deforestation and other land-cover change (largely from developing countries in the tropics). A given temperature change in degrees Celsius (ºC) can be converted into a change in degrees Fahrenheit (ºF) by multiplying by .8. Thus, a change of 0.8ºC corresponds to a change of 0.8 x .8 = .44ºF.