Climate change is the variability in temperature, rain fall, and snow and wind pattern of a specific location for a period of time. Climate change is a real and urgent challenge that is affecting people and the environment worldwide. Significant changes are occurring on Earth, including increasing air and ocean temperatures, widespread melting of snow and ice, and rising sea levels. As the climate continues to warm, more changes are expected to occur and many effects will become more pronounced over time.
Human activities are increasing the amount of greenhouse gases in the atmosphere. Some amount of greenhouse gases is necessary for life to exist on Earth; they trap heat in the atmosphere, keeping the planet warm and in a state of equilibrium. But above the optimum level, greenhouse effect is being strengthened as human activities add more of these gases to the atmosphere, resulting in a shift in the Earths equilibrium. Human activities like burning of fossil fuels, cutting down forests, and developing land for farms, cities, and roads. These activities all release greenhouse gases into the atmosphere. These greenhouse gases include carbon dioxide (CO2), methane (CH4) and nitrogen dioxide (N2O), and these gases are trapped in earths atmosphere and caused a rise in the amount of heat from the sun withheld in the Earths atmosphere, heat that would normally be radiated back into space. This increase in heat has led to the greenhouse effect, resulting in climate change.
The main characteristics of climate change are:
Average temperature both in summer and winter has increased.
The increases in temperature will cause increasing glacier out-falls and the ongoing process of land degradation by increase of salt affected areas.
Due to melting of glaciers and heavier rainfall more water will be available in a river which causes floods.
Increase of ocean temperature and melting of glaciers will cause to increase sea level around the world.
Increase of winter temperature is more intensive than summer temperature during the last decade. So duration of seasons has changed, winter has shortened while summer has prolonged.
Due to shortening of winter season productivity of rabi crops like wheat is affected. It is estimated that for every 1 0C increase of temperature wheat production is reduced by 7%.
Rainfall received in various regions has declined significantly and became more erratic.
Monsoon rains occur late and are heavier in certain areas especially in Sindh and KP Provinces. Winter rains, on the other has declined.
Elevation of CO2 in atmosphere cause acidification of the oceans due to absorption of CO2 in ocean.
During 20th century, the increase in the global temperature was recorded as 0.76°C but in the first decade of this century 0.6°C rise has been noticed. Pakistan having warm climate is particularly vulnerable to climate change regardless of that it makes a tiny contribution to total greenhouse gases emission which is less than 1%. It lies in a region where expected rise of temperature is higher as compare to other regions. The temperature data of 24 districts of Punjab Province shows that average maximum and minimum temperature increased 0.96 0C and 0.93 0C respectively from 1960-1988. While during 1988-2014 Maximum and minimum temperature increased 1.21 0C and 1.03 0C. In some districts like Faisalabad, Murree and Sialkot average maximum temperature increased 2.23 0C, 2.38 0C, 3.09 0C respectively (Pakistan Meteorological Department). In 2008 Pakistans total GHG emissions were 310 million tons of CO2 equivalents. These comprised: CO2 54%; Methane (CH4) 36%; Nitrous Oxide (N2O) 9%; Carbon Monoxide (CO) 0.7%; and Non-Methane Volatile Organic Compounds 0.3%. (Source: National GHG inventory 2008). The energy sector is the single largest source of GHG emission in Pakistan; it accounts for nearly 51% of these emissions and is followed by the agriculture sector (39%), industrial processes (6%), land use, land use change and forestry (3%) emissions and waste (1%) (National GHG inventory 2008). So there is need to take some precautionary steps to prepare for and diminish disasters of climate change.
Following steps must be taken in consideration to prepare for such kind of calamities:
Construction of Dams: By construction of dams and improvement of water management and storage system. By doing so water for crops will be available as well as disaster of flood can be mitigated.
Improving Crop Varieties: By improving and introducing heat/ drought and salt tolerant varieties of crops which are affected least by environmental condition changes.
Emergency System: Development of flood control and drought monitoring system and early warning system can help people prepare for that condition and reduce the disaster of flood and drought.
Soil Reclamation: By reclamation of salt affected and water logged soils cultivated area is increased and increase crop production which will balance the reduction of crop productivity due to climate change.
Soil Fertility Maintenance: Erosion control and soil fertility maintenance can help improvement of crop production.
Carbon Sequestration: Control of deforestation and Carbon sequestration by reforestation, green manuring, no-till farming etc. can reduce the increasing temperature.
Awareness: Public awareness to check GHGs emissions can help reducing the greenhouse effect and decreasing temperature.
Training for adoption: Capacity building and training to adapt people according to climate change.
Govt. Policies: Govt. must develop such policies which help conservation of resources and controlling GHGs emission.
Pakistan is vulnerable to threat of climate change, which have adverse effect on agriculture and environment. In agriculture food production is reduced and some disasters like floods and drought are great threat for the humans. There are different measures to prepare and diminish such calamities. Govt. agencies and people are aware of the threats of climate change. There is also adoption of techniques and methods of overcoming problems of climate change but more research and work is needed to overcome all the problems.