Individual species and ecosystems have evolved over millions of years into a complex interdependence. The ecological arguments for conserving biodiversity are therefore based on the premise that we need to preserve biodiversity to maintain our own life support systems. Two linked issues which are currently of great ecological concern include world-wide deforestation and global climate change. Forests not only harbour untold numbers of different species, but also play a critical role in regulating climate. The destruction of forests, particularly by burning, results in great increases in the amount of carbon in the atmosphere for two reasons. Firstly, there is a great reduction in the amount of carbon dioxide taken in by plants for photosynthesis and secondly, burning releases huge quantities of carbon dioxide into the atmosphere. This is significant because carbon dioxide is one of the main greenhouse gases in the current global warming trend. Average global temperatures have been showing a steadily increasing trend. Snow and ice cover have decreased, deep ocean temperatures have increased and global sea levels have risen by 100 - 200 mm over the last century. If current trends continue, scientists predict that the earth could be on average 1 degree Celsius warmer by 2025 and 3 degree Celsius warmer by 2100. These changes, while small, could have drastic effects. As an example, average temperatures in the last Ice Age were only 5 degree Celsius colder than current temperatures. Rising sea levels which could drown many of our major cities, extreme weather conditions resulting in drought, flooding and hurricanes, together with changes in the distribution of disease-bearing organisms are all predicted effects of climate change. Forests also affect rainfall patterns through transpiration losses and protect the watershed of vast areas. Deforestation therefore results in local changes in the amount and distribution of rainfall. It often also results in erosion and loss of soil and often to flooding. Devastating flooding in many regions of China over the past few years has been largely attributed to deforestation.
Zubair Ahmad Ahanger
Depratment of Botany
University of Kashmir

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