Climate change impacts on water, agriculture
Globally agriculture sector is assailable to climate change. Pakistan stands amongst the extremely affected countries by the fluctuation of climate. Food security and water availability would be badly affected, because of fickle rainfall patterns, weather trends, and extreme events such as floods. Climate change experts warned Pakistan due to the existence of five major hazards related to climate change. There will be glacial retreats, floods, and an increase in sea level, average temperature and droughts. Due to the severe fluctuations in climate it is estimated that by 2030 crop yield per unit area will decrease to greater extent in many regions of the country. Unfortunately, this phenomenon is yet seen as a global prospect and the government in Pakistan has been unable to root its original context. This shackles policy making on this very issue and worsen the problem.
A noteworthy fact is that current and expected future climatic scenario in Pakistan has many hazards for agriculture sector. The late onset and early ending of winter season seems to have reduced the length of the growing season for Rabi crops like wheat and grams. The rises in winter temperature is causing the forced maturity of grains and reducing economic yield. Monsoon rains will have much higher intensity than normal pattern. Droughts and floods are predicted in Pakistan during the past few years clearly indicate that these are imminent threats for the country. The pattern of rainfall throughout the country has deviated widely, and the duration and intensity of the summer season has increased. Hindu Kush Karakoram-Himalayan glaciers are predominant water sources for Indus River and its tributaries which are seemed to be fade away rapidly due to global warming. These factors suggest that water, food and energy security in Pakistan will face a crucial time.
Global warming is expected to cause continued fall in snowpack and earlier snowmelt which will lead towards the reduction in water supplies. Wheat, staple crop in Pakistan, is grown in the Rabi (winter) season if not properly irrigated; it can result in lesser grain production. By 2040, in Pakistan temperature is anticipated to rise by 3 Celsius. The increase in temperature increase crop evapo-transpiration and loss of soil moisture. Climate change impact studies unwraps that water availability are contrived to decrease by 10-30% over some dry areas of country. The Indus River is extremely susceptible to climate variability due to the high portion of its flow derived from glaciers of the Hindukush and the Karakoram, which supports nearly 90% of our agriculture. With climate heat up, many glaciers will no longer exist to modulate the flow of these rivers. Thus Pakistans agriculture sector, which depends on glacier water, will face more extreme water shortage, variability and a potential reduction in water availability for agriculture.
There would be an increase in the intensity and the incidence of floods by increasing intensity and magnitude of precipitation especially as rainfall patterns have become unpredictable. More and prolonged warmer summer months, a continuation of contemporary retreat will eventuallyexhaust the glacial ice and reduce or eliminate runoff. So a reduction will occur in ability to irrigate crops and summer stream flows required to keep dams and reservoirs replenished.
Pakistans glaciers are expected to melt by 2035 which will have a disastrous effect on freshwater flows. Studies demonstrated that with just a 1oC rise in temperature, wheat yield in Pakistan is estimated to decline by 6-9%. Even smaller increase in temperature can severely affect cash crops like mango and cotton. Crop growth periods relates to temperature. In annual crops like sugarcane, this rise in temperature will reduced time span between sowing and harvesting. The shortening of such a cycle could have an adverse effect on productivity because senescence would occur earlier. Horticultural crops are more vulnerable to changing conditions of climate for agricultural crops. Vegetables will be hit hard by temperature fluctuations. Climate change will increase the attack of crop pests and diseases and imply spatial shifts in potential areas of agricultural sector. Global warming will cause an increase in rainfall in some areas, which will result an increase in humidity combined with higher temperature favors the development of fungal diseases similarly an increased pressure of disease vectors. The climate change also affects grain and forage quality. Under increasing elevated CO 2 level the amylase content (major determinant of cooking quality) of rice grain increased and zinc and iron concentration decrease. Under elevated CO2 level nitrogen uptake will reduce which will lead towards lower nutritional quality of crops.
Rangelands will under stress from prolonged droughts by changing climatic conditions. This will result in the reduction of the cover of shrubs and trees. Pakistan is already having small forest resources. Episodic and scanty rainfalls due to changing in rainfall trend with the current continuity of climatic changes, leads to induce drought conditions. In such a future scenario 20-30% production of live stock will decrease, creating juncture in meat, poultry and milk productivity. Water is not only going to become more expensive but it is also less reliable. Climate change is responsible for this sorry state of affairs. Some of the affects of climate change are evident indifferent sectors of Pakistan. Agriculture, which is considered as a back bone of the country should be severely affected. Time has come for the policymakers to think seriously about this issue by adopting future strategies to save our motherland. There is a dire need to handle this sensitive issue with an iron hand otherwise it may engulf the agricultural system of Pakistan.