Global warming is the continuing rise in the average temperature of the earth. Scientist agree that the main cause of the current global warming trend is the human use of fossil fuels. Which, releases Carbon Dioxide, Methane and other gases that contribute to the Green House Effect; warming that results when heat is trapped within the atmosphere instead of escaping into space.
This warming contributes to climate change; which is defined as a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years.
There is evidence that the world’s climate is changing and threatening the world’s environmental, social and economic development including the agricultural sector. This change in weather patterns has come with challenges such as tropical storms, wildfire, soil erosion, pests and diseases which are causing devastating losses to farmer’s yields.
A report “Global Warming and Agriculture” stated that by the 2080s, average temperatures would have risen by 3 degree Celsius. Resulting in a 16% decrease in agricultural production across the world. However, the impact will be felt more acutely by developing countries especially those close to the equator.
Another report by a group of researchers, who assess and summarise the scientific literature on climate change; state that, the major food crops such as wheat, corn and rice, yields are likely to start decreasing by 2030 and decline up to 2% a decade. Increased concentrations of carbon dioxide, changes in temperature and precipitation, the increased frequency of hot days and changing patterns of rainfall, crop disease all play a role.
Major climatic changes directly affecting agriculture include;
- Rising sea levels decreasing coastal lands.
- Shifting rainfall patterns will change the growing locations of various crops.
- Shifting temperature ranges will affect changes in the length of growing season.
The relationship between climate change and agriculture is a two-way street. Agriculture contributes to climate change through increased methane production from livestock. Whilst climate change in general adversely affects agriculture.
It is thus clear that agriculture needs to undergo a radical overhaul to become more sustainable. This is not just because it is important to take care of our environment, but also because sustainability is absolutely necessary for the continuing productivity of the agro system.
The IAASTD report (2008) makes this clear by saying that greater emphasis is needed on safeguarding natural resources and agro ecological practices as well as on tapping the wide range of traditional knowledge held by local communities and farmers, which can work in partnership with formal science and technology. It stresses that sustainable agriculture that is biodiversity based including agro ecology is resilient, productive, beneficial to poor farmers and allows adaptation to climate change.
Sustainable agriculture should;
- Make best use of nature’s goods and services by integrating natural, regenerative processes e.g nutrients recycling, nitrogen fixation, soil regeneration and natural enemies of pests.
- Rely on the knowledge and skills of farmers, improving their self-reliance.
- Promote and protect social capital; peoples capacities to work together to solve problems.
- Depend on locally adapted practices to innovate in the face of uncertainty.
- Minimise non-renewable inputs (pesticides and fertilisers) that damage the environment.
- Be multifunctional and contribute to public goods such as clean water, wildfire, and carbon sequestration in soils, flood protection and landscape quality.
Sustainable agriculture practices include;
- Crop rotations that mitigate weed disease and insect problems.
- Increase available soil nitrogen and reduce the need for synthetic fertilisers.
- Reduction in soil erosion.
- Soil conserving tillage.
- Improve water conservation and water harvesting practices.
- Implementation of good farming practices.
- Educating the farmers on adaptive measures to be taken.
Therefore, global warming and by extension, climate change is no longer a matter for individual countries. It is now a global issue and a serious one at that.
In conclusion, we would all feel better if global warming could be attributed to the dying sun. But the overwhelming evidence points fingers to our own actions as being the accelerating force, towards our imminent destruction of the planet. We all need to be more educated on climate change and its consequences.
Environmental science and technology (Policy Analysis) 40(4) :1114-1119
IAASTD. 2008. International Assessment of Agriculture Knowledge, Science and Technology for Development.
Third World Networking. Briefing paper 5, June 2003.
William R. Cline. IMF 2008. Global Warming and Agriculture