According to IPCC (2007), agricultural land covers 40-50% of the world’s land surface and this sector accounts for 14% of annual global greenhouse gas emission, which makes agriculture is one of the main contributor to climate change. Total global greenhouse gas contribution of agriculture from both direct and indirect sources extended up to 32% and about 74% of total agricultural related greenhouse gas emissions originate in developing countries.
The most prominent sources include:
- land conversion to agriculture,
- Nitrous oxide released from soils,
- Methane from cattle and enteric fermentation,
- Biomass burning,
- Rice production,
- Fertilizer production,
- Farm machinery and
- Pesticide production.
Climate change on agriculture and farming community
The cumulative impact of climate induced from increase of GHG will have wide range of cross-sectorial impacts affecting health, water and energy resources, ecosystems, and land use. This leads to meaningful economic consequences for the wellbeing and sustainable development of rural populations. The impacts of climate change to agriculture over the next 50 to 100 years include:
- Changing spatial and inter-temporal variability in stream flows,
- Onset of rain days, and dry spells,
- More frequent floods and droughts
- Greater erosion rates from more intense rainfall events and flooding,
- Increased crop water requirements from high temperatures, reduced precipitation and increased evaporation,
- Yield changes for crops including maize, wheat, and rice. Resulting in changes in crop and management choices,
- Increased heat and water stress on livestock,
- Management (i.e. stock increases) under increased temperatures with a different mix of more heat resistant.
- Higher temperatures in arid and semi-arid regions will likely depress crop yields and shorten the growing season due to longer periods of excessive heat.
However, climate change will not equally affect all countries and regions, even if Africa represents only 3.6% of total global emissions of GHG, Africa will be one of the continents that will be hard hit by the impact of climate change due to an increased temperature and water scarcity. The report pointed out that there is “very high confidence” that agricultural production and food security in many African countries will be severely affected by climate change and climate variability. This means that countries already struggling with food security are likely to find they struggle still harder in the future. Without compensating by climate smart innovations, climate change will ultimately cause a decrease in annual GDP of 4% in Africa. An increase of global temperatures of just 2-4 degrees Celsius above pre-industrial levels could reduce crop yields by 15-35 percent in Africa , While an increase of two degrees alone could potentially cause the extinction of millions of domestic and wild species.
Adaptation to climate change
The vulnerability of agricultural system depends on its exposure and sensitivity to climate changes, and on its ability to manage these changes (IPCC, 2001). Climate change adaptation enhanced by altering exposure, reducing sensitivity of the system to climate change impacts and increasing the adaptive capacity of the system while explicitly recognizing sector specific consequences. Adaptation programs include provision of crop and livestock insurance, social safety nets, new irrigation schemes and local management strategies, as well as research and development of stress resistant crop. Options for adapting agriculture to climate change have related cost for research, Irrigation efficiency, Irrigation expansion and development of infrastructures.
Improving the use of climate science data for agricultural planning can reduce the uncertainties generated by climate change, improve early warning systems for drought, flood, pest and disease incidence to increase the capacity of farmers and agricultural planners to allocate resources effectively and reduce risks.
Mitigation for climate change
Climate change mitigation constitutes anthropogenic intervention to reduce the sources or enhance the sinks of GHG to reduce the causes of climate change by limiting the amount of heat trapping gases that emitted into the Earth’s atmosphere. Agriculture had immense potential for carbon sinks, as well as reducing emissions per unit of agricultural product for sustainable development co-benefits. Intervention pillars in climate mitigation are reduction of emissions, avoided the emissions and creating sinks that can remove emissions. Lower rates of agricultural expansion in natural habitats, agro-forestry, treating of degraded lands, reduction or using more efficient use of nitrogenous inputs, better management of manure, and use of feed that increases livestock digestive efficiency are some to be mentioned.
soil carbon sequestration could be realized, if carbon markets could introduce to “ provide strong incentives for public and private carbon funds in developed countries to buy agriculture-related emission reductions from developing countries. Moreover using improved nutrient management could increase the plant uptake efficiency of applied nitrogen; reduce N2O emissions, while contributing to soil C sequestration. Agroforestry systems tend to sequester much greater quantities of carbon than agricultural systems without trees. Planting trees in agricultural lands is relatively efficient and cost effective compared to other mitigation strategies, and provides a range of co-benefits important for improved farm family livelihoods and climate change adaptation. Climate change mitigation through improved livestock brought by research on ruminant animals, storage and capture technologies for manure and conversion of emissions into biogas are additional contributions that agriculture can make towards mitigating climate change. The anaerobic digestion of manure stored as a liquid or slurry can lower methane emissions and produce useful energy, while the composting solid manures can lower emissions and produce useful organic amendments for soils.
Climate smart agriculture (CSA) way forward
The future of agricultural production relies on both designing new ways to adapt to the likely consequences of climate change, as well as changing agricultural practices to mitigate the cli-mate damage that current practices cause, all without undermining food security, rural development and livelihoods. Climate-smart agriculture is a practice that sustainably increases productivity, resilience (adaptation), reduces/removes GHGs (mitigation) and enhances achievement of national food security and development goals. Efficiency, resilience, adaptive capacity and mitigation potential of the production systems can be enhanced through improving its various components. To materialize CSA, major transformation of the agriculture sector is necessary and will require institutional and policy support. Better-aligned policy approaches across agricultural, environmental and financial boundaries and innovative institutional arrangements to promote their implementation. Enabling policy environment to promote CSA is greater coherence, coordination and integration between climate change, agricultural development and food security policy processes.