The greenhouse effect, climate change and sea-level rise : tropical perspective

Abstract

The prospect of global warming as a result of the increase in greenhouse gases in the Earth's atmosphere has become in recent years a topic of major concern in the scientific and the wider community. In this paper we review in broad terms the present state of research throughout the world on the greenhouse effect, climate change, sea-level rise, and the impacts these changes may have on the environment, agriculture and society generally. We discuss in particular the results for tropical regions. General circulation modelling results to date indicate that the tropics are likely to warm by 2-4°C for an effective doubling of atmospheric CO2. The possible impact on the frequency and intensity of tropical cyclones, the monsoons, and El Nino-Southern Oscillation (ENSO) are discussed.

The existence of certain gases in the atmosphere which trap long-wave radiation emitted by the earth's surface keeps global surface temperature around 33° warmer than it would otherwise be (Mitchell, 1989). This phenomenon is known as the greenhouse effect. The main greenhouse gas is water vapour, but a significant contribution is made by various other gases, most of which are known to be increasing in the Earth's atmosphere due to emissions directly associated with industry and other human activity. There is little doubt that this increase will enhance the greenhouse effect and raise global surface temperature, although there is uncertainty over the expected rate of warming, the response of other climate factors (rainfall, wind, etc.) and expected climate change at a regional level.