Fluctuation in the average weather pattern of a specific region experienced for a longer period of time is termed as climate change.
Different indicators of climate change are change in wind pattern, temperature and precipitation. Increased concentration of greenhouse gases is a principle cause of climate change. There happens to be an annual increase of 0.6 °C in average earth’s temperature in previous century and it is estimated to be increase up to 1.4 to 5.8 ºC till the end of this century.
Anthropogenic activities i.e. depletion of forests, burning of fuels and conversion of forest into agricultural land are responsible for this rapid global warming. Agriculture productivity is mainly governed by genotype, environment and management practices. In the form of environment climate change is of immense importance.
Agricultural Productivity is threatened by changing climate. A number of variables (mainly temperature, water, air currents, rainfall pattern, land suitability, sowing and harvesting dates) are responsible for climate change.
Majority of people (almost 75%) in Pakistan are directly or indirectly dependent on agriculture for their livelihood and it shares about 21% of the national GDP. Pakistan was ranked 28th among countries that are most vulnerable to climate change. Later on, Pakistan was present in the report of World Bank related to most threatened (12) countries because of climate change.
Geographical position of Pakistan is responsible for exponential increase in temperature compared to global average. Pakistan has been facing the effects of climate change without being aware of it. Some negative impacts of climate change includes drought spells, dry winters, intense rains, late monsoon, long dry spells, rising temperature, and reduced productivity in agriculture sector may result due to climate change in Pakistan.
Scientist fear that climate change may alter or take away monsoon from Indo-Pak continent. Floods that struck the country during last year’s are supposed to be the outcome of these changes.
Almost 90-95 percent of the freshwater resources are used by the agricultural sector. Out of 22.05 million hectares of cultivated area, 19.02 million hectares is under irrigation. Both rain fed and irrigated agriculture is vulnerable to climate changes. According to World Bank 30 percent of the water reservoirs of country are expected to deplete in the next 20 years.
Climate changes have adversely affected the rain patterns and ultimately water supplies to crops. Acute weather conditions damaged the crops during the year 2012-13. Area under rice and cotton crops was declined as a result of late wheat harvesting and water shortage. Later in September 2012, localized flooding and heavy rains adversely affected the rice and cotton crops in southern Punjab and nearby areas in Baluchistan.
Potential Threats of Climate Change
Glacier outfalls and landslides may increase. Rivers of Pakistan are mainly fed by Himalayan Hindu Kush-Karakoram glaciers, which are receding rapidly as a result of global warming. Sideways the demand of the water is increasing as a result of high evapotranspiration at eminent temperatures. Drastic changes in species patterns i.e. it is expected that fast growing species will take over and will have serious effects on native biodiversity.
Moreover shift in special boundaries may also occur (conifers and alpine species are shifting towards higher altitudes). Rain-fed agriculture is particularly affected due to uncertain and erratic rainfall patterns. In summers, flooding occurs as a result of intensive rains and increase loads of sedimentation from upstream. Salinization and water logging are also among the potent climatic threats.
After floods and heavy rains there is increased incidence of pests, insects and diseases because of more humid and warmer climate. However in winters, acute water shortage may occur due to increase water requirements of crops. Water level of reservoirs has decreased to threating levels as a result of late winter rains or dry spells.
There is a spatiotemporal shift in agro-ecological boundaries and cropping zones i.e. seasonal length of rice and wheat has shortened, expecting a loss of production of about 2-4% for rice and 1.5-2.5% for wheat till 2020. Decrease in production of many cereal crops like, wheat, rice and other cash crops is expected in all regions except Northern areas where raised temperatures may favor wheat production.
Livestock sector is equally vulnerable to climate change as high temperature leads to physiological stress, decreased milk and meat production, epidemics and changed animal habits. Indirectly it affects animal health by reduced fodder production decreased palatability and nutritional quality of forage owing to increased concentration of CO2.
A Way Forward
This alarming situation demands immediate attention and serious efforts. Different management practices can be employed in this regard. High efficiency irrigation systems and short duration varieties for rice, wheat and other crops should be encouraged. Moreover conservation agriculture practices along with climate resilient varieties (drought and heat resistant varieties of wheat, maize, rice and cotton) would help to combat the climate change.
Direction and shifts of special boundaries should also be mapped and modeled for cropping zones particularly and agro-ecological regions in general. Agro-biodiversity and genetic variability should also be conserved via gene banks. There should be capacity building of farming community about the potent threats of climate change.
The government should put heavy investment on raising awareness about climate change and its mitigation. Different research groups should reevaluate cropping patterns consistent with new world of climate changes. Extension workers can play a significant role in the dissemination of scientific information about climate change and its tentative effects on the crops, to end-users.
Comparative advantages in agro-based industries and agriculture should be established considering the changing climate situation at regional, national and global level. A national climate change policy needs to be devised for defining role of federation, provinces private and public sector.
This article is collectively authored by Rahil Shahzad1 Iqra Ghafor2, – 1 Agricultural Biotechnology Research Institute, Ayub Agricultural Research Institute Faisalabad, 2 Wheat Research Institute, Ayub Agricultural Research Institute Faisalabad.