The world's climatic condition is changing very rapidly and differently. Climate change affects every country and every continent (according to UN) thereby disrupting national economies, people's lives, communities, food, and resources. Climate change has risen to be one of the biggest and urgent issues of the present world and a great scientific consensus is concerned with climate change.
What is climate change?
Climate change occurs when changes in the Earth's climate system result in new weather patterns that last for at least a few decades, and maybe for millions of years. This usually is referred to as the greenhouse effect in which sunlight enters the atmosphere and heats the earth. The heat is radiated back to space, but some certain gasses like CO2 in the atmosphere traps the heat and prevent it from escaping. Thereafter remitting it back to the earth in all direction and forcing a climate change. There are basically two major causes responsible for the emission of greenhouse gasses; natural causes and human activities. On the other hand, Agriculture involves the whole process of farming, including cultivation of soil for growing of crops and the rearing of animals to produce food and other products.
Agriculture and climate change are inextricably linked such that agriculture is not only affected by climate, but it also contributes to climate change itself. As a matter of fact, Agriculture contributes to about 24% of the greenhouse gas emission, an example of which is seen in the process of rice farming and in the belching of ruminant animals which results in methane emission- a stronger heat trapper than carbon-dioxide. Nevertheless, considering the importance of agriculture to human lives, climate change causes uncertainty such that farmers are not assured of a bountiful or profitable harvest, In this way, food security is threatened and it is advised that actions be taken against climate change.
Change in climate affects a wide range of areas in agriculture ranging from crop production, livestock, and fisheries.
IMPACT ON CROPS
For any particular crop, the effect of increased temperature depends on the crops optimal temperature for growth and reproduction. For instance, if the temperature exceeds a crop's optimum temperature, yields will decline. However, in some areas, warming may benefit some types of crops typically planted there, or allow farmers to shift to crops that are suitable to grow under warm conditions.
Extreme events, especially floods and droughts can also harm crops and reduce yield, for example, in October 2018, flooding hit about 10,000 farmers in Nigeria resulting in a shortage of rice, the country's most staple food. Also, many weeds, pests, and fungi thrive under places with warmer temperatures, wetter climates, and increased CO2 levels. Currently, Nigerian farmers spend more than $400 million yearly fighting pests and weeds which compete with crops for light, water, and nutrients. The survival and distribution of pests and weeds are likely to increase with climate change and this can cause new problems crops were previously unexposed to.
IMPACT ON LIVESTOCK
The negative effects of increased temperature on feed intake, reproduction, and performance on various livestock species is something that is reasonably well understood. For example, for most livestock species, such as cattle, sheep, goats, pig and chickens, temperatures between 10 and 30°C is when they perform the best. But for each 1°C increase above that, all species reduce their feed intake by 3-5 percent. Without a doubt, this will have far-reaching effects on the quality and quantity of livestock species.
Some areas could also experience longer and more intense droughts resulting from higher temperatures and reduced precipitation which in-turn spells widespread negative impacts on forage quality and as a consequence, livestock productivity. Climate change may also increase the dominance of disease-causing parasites and pests that affect livestock. For example, the early onset of spring and winter may encourage the growth and easy survival of pathogenic organisms.
IMPACT ON FISHERIES
Climate change has a significant impact on freshwater and marine aquatic systems and hence, on the fisheries and aquaculture. Fisheries and aquaculture are highly vulnerable to changes in weather pattern and the impacts could be negative or positive and vary from one region to the other. Increased water temperatures affect fish physiological processes, thereby affecting spawning, survival of the juveniles, population size, production, and yield. The impact of increased flooding of the freshwater bodies could be negative through erosion of watershed, destruction of fish feed and breeding habitats, decrease in primary productivity and alteration of the normal resilience of the aquatic systems, or positive through expansion of aquatic habitats for primary fish production, especially during dry season. Drought aggravates the drawdown of lakes and reservoirs and causes the insufficient flow of water in the river basins used for spawning and primary fish production thereby affecting general fish production.
Also, the rise in the water level of the Atlantic ocean leads to an intrusion of more salty water into the river delta areas, thus affecting the distribution of both the freshwater and marine fishes as a result of the changes to the physical and chemical properties of the waters. The impact ultimately affects fish population, production, and supply as well as food security, thereby affecting the livelihood of over 35 million people employed into the fisheries industry worldwide.
Strategies and policy measures need to be evolved to combat the observable and projected impact of climate change on fisheries and aquaculture in order to protect the livelihood of the fishing communities and improve food security.
HOW CAN AGRICULTURE ADAPT?
Adaptation strategies are short and long-term changes to human activities that respond to the effects of climate change. In agriculture, adaptation will require cost-effective investment in water infrastructure, emergency preparation for and response to extreme weather events, development of resilient crop varieties that tolerate temperature and precipitation stresses, and new or improved land use and management practices.
Tools for Adaptation