Climate change is the greatest threat to modern times and is greatly affecting socio-economic sectors like health, food production, energy consumption and security and natural resource management.
The most recent scientific assessment by the Intergovernmental Panel on Climate Change (IPCC) estimates that the global averaged surface temperature on earth will increase by 1 to 3.5øC (about 2 to 6øF) by the year 2100, with an associated rise in sea level of 15 to 95 cm (about 6 to 37 inches).
Effects of global warming can be witnessed in Pakistan as well. Few years ago, December was considered the coolest month of the year. But this year, though there is a bit chill at night but days are hot. Sometimes the days are so much hot that people have no choice but to put off their warmer clothes. Talking to APP, Chief Meteorologist Ghulam Rasool said, “As compared to previous years, November was much dry this year and December will also remain dry and no major weather system is expected in coming days.” The harmful impacts of this global warming are already manifesting themselves around the world in the form of extreme weather events like storms, tornadoes, floods and droughts, all of which have been mounting in frequency and intensity.
As a result, the world today suffers around 400-500 natural disasters on average in a year, up from 125 in the 1980s.
According to the Fourth IPCC Assessment Report, the evidence of predicted impacts of climate change is slowly unfolding. Crop yield growth rates are declining in most parts of the world, partially as a consequence of rising temperatures, while increases in prevalence of climate-induced diseases have also been recorded.
There is also evidence of accelerating recession of most glaciers on Earth, rainfall variability and changes in marine ecosystems.
Another serious threat arising from climate change is to freshwater availability which is projected to decline especially in large river basins and adversely affect more than a billion people by the 2050s.
Climate change is also likely to have wide-ranging and mostly adverse impacts on human health. The projected increase in the duration and frequency of heat waves is expected to increase mortality rates as a result of heat stress, especially in areas where people are not equipped to deal with warmer temperatures. To a lesser extent, increases in winter temperatures in high latitudes could lead to decreases in mortality rates. Climate change is also expected to lead to increases in the potential transmission of vector borne diseases, including malaria, dengue, and yellow fever, extending the range of organisms such as insects that carry these diseases into the temperate zone, including parts of the United States, Europe, and Asia.
