| Popis: |
The Intergovernmental Panel on Climate Change (IPCC) released the Assessment Report number 4 which crystallised scientific evidence documenting unequivocal climate change. Global average air temperatures are rising and this rise has of late become so alarming that the last 11 (1995-2006) years show the highest increase since 1906 when instrumental records begun. Evidence for rising sea levels shows that since 1961, the global sea level rise has averaged at a rate of 1.8 mm, whereas since 1993- 2006, this value has increased at a much higher value of 3.1 mm, higher than the normal global rate observed over the geological history. The Sahara (Sahel region), the Mediterranean, Southern Africa and parts of southern Asia have all recorded decreases in the volume of precipitation. These changes in precipitation have led to the occurrence of extreme events in Southern Africa, such as floods and drought in a much more frequent manner. However the frequency of these events is yet to be properly understood. Soil samples reveal extreme event frequency and groundwater perturbations. Bee colonies are sensitive to small changes in environment. Surface and ground water samples help compare the changes obtained from honey samples with past events in the last 100 to 200 years. Identification of colony collapse disorder (CCD) could entail a complex of environmental and/or anthropogenic factors including climate change. All these facts have been used to gauge small scale changes in climate. The results are being slowly accumulated and will help us predict the rate of cultivated crop stability in the future, and hence address issues of food security and water scarcity, so as to enhance traditional methods of adaptation. |
