Climate change is a phenomenon due to emissions of green house gases from fuel combustion deforestation, urbanization and industrialization resulting variations in solar energy, temperature and precipitation. It is a real threat to the lives in the world that largely affects water resources, agriculture, coastal regions, freshwater habitats, vegetation and forest, snow cover and melting and geological processes such as landslide, desertification and floods and has long term affects on food security as well as in human health. In Nepal average temperature increase was recorded as 0.060 C per year and that in Terai and Himalaya was 0.040 and 0.080 C per year respectively. It may be due to solar radiation absorbed by glacial lakes as well as radiation absorbed by land because of snow melting in the Himalayan region. Likewise, Rainfall was recorded minimum in the year 1972, 1977, 1992 and 2005 and maximum in the year 1975, 1985 and 1998. Erratic rainfall events (i.e. higher intensity of rains but less number of rainy days and unusual rain) with no decrease in total amount of annual precipitation have been experienced. Such events increase possibility of climate extremes like irregular monsoon pattern, drought and floods. For eg. there were rain deficit in eastern terai and western terai regions, normal rain in far western region and heavy rain in the mid western region creating flood, landslide and inundation.

Impact of climate change in Agriculture

Every crop has a temperature range for their vegetative and reproductive growth. When temperature falls below the range or exceeded the upper limit then crop production faces constraints.  A study found that 10 C increase in maximum temperature at vegetative, reproductive and ripening stages there was a decrease in Aman rice production by 2.94, 53.06 and 17.28 tons respectively (Islam, 2008). With the change in temperature (by 20C and 40C the prospects of growing wheat and potato would be severely impaired. Production loss may exceed 60% of the achievable yields.

Impacts on Nepalese Agriculture

 Agriculture is the most important livelihood sector and provides a substantial proportion of rural incomes and employment opportunities. Rapid agricultural development along with improvement of the environment conservation is a pre requisite to alleviate rural poverty, the development of agriculture will to a large extent determine alleviation or aggravation of poverty in the Hindu-Kush region. The country is susceptible to disasters, including flash flood, slow melting, ice avalanche in mountains and droughts and floods in the terai. The raising temperature and emission of CO2 to some extent is helpful in production by enhancing photosynthetic processes, water use efficiency, shortening physiological period. The impacts on agriculture are decrease of productive land in some region and increase in some other region. So it is a complex problem to the world. Rising CO2 promotes plant growth and if the CO2 gas doubles, yields will increase by 40%.

Evidences of Climate change in Nepal and Nepalese agriculture. New records for Warmest year in the history. Late or pre-monsoon, unusual precipitation, decreased rainy days and intense rainfall events caused more run off and low ground water recharge. Extreme fog conditions have recently been observed in the terai regions. Traditional rainfalls of Jestha and Asar have been shifted in Shrawan and Bhadra in Kathmandu. Glaciers in mountains shrinking at alarming rate. Kathmandu valley frost day decreasing winter cold shifted to a month later than regular and snowfall in KTM after 60 years in 2007. Similarly, Darchula district of the country faced unusual snow fall in 2008 affecting collection of precious meditional herbs. Mosquito from terai and mid hills being able to survive in high hills (Illam, Mustang, Helambu). Eastern terai faced rain deficit in the year 2005/2006 by early monsoon and crop production reduced by 12.5% on national basis. Nearly 10% agricultural land were left fallow due to rain deficit but mid western terai faced heavy rain with floods which reduced production by 30% in the year. Early maturity of the crops due to increase in temperature may help to have more crops in the same crop cycle (NARC annual report). Increase in temperature cause more damage in terai region and will be more favorable to agriculture in the hills and mountains For eg; Maize, chilly, tomato and cucumber are now being adapted in Mustang district of the country. Similarly, vector born disease of human and livestock can be expected to shift in higher eco zones too.

Research Potential of Nepalese Agriculture to adapt Climate Change

Ø  Improvement of heat, drought and pest resistant crops

Ø  Improvements in resources for irrigation efficiencies: drip and sprinkle irrigation.

Ø  Research in water and nutrient management in various agro-ecologies to meet the climate change.

Ø  Research in green manuring crops, cover crops to preserve soil moisture, soil organic matter and micro nutrients

Ø  Research on climate prediction related models and their application

Ø  Research on land use planning, watershed management, vulnerability assessment and resource management.