A person usually has an average of 2700 calories. 84% of these calories are from plants, 54% being from cereals, which include wheat and rice, and 16% from rice. Out of 40% of the world’s food, 20% are from irrigated farms.
Ninety-five percent of the food insecurities are found in the tropics and subtropics. People in these regions are malnourished due to lack of enough calories to sustain a healthy lifestyle. The main diet for these people includes rice (26%), wheat (17%), sugar cane (8%), maize (6%), nuts (5%), cassava (4%), and others (34%). It is apparent that they heavily depend on agriculture for both food and income. Despite the lack of food, the population in these regions increases at an alarming rate.
CO2 and Temperature change
The amount of carbon dioxide in the atmosphere is expected to increase. This will mostly depend on the population and economic growth, future choice for energy, and government policies on development versus global governance. Assuming that the global population increases from 7.5 billion to 9 billion, the poor people develop and used more energy and the current CO2 emissions remain constant till 2100, the levels of CO2 will increase from 400ppm to 570ppm (400ppm+2ppm/yr x 85yrs).
An increase in CO2 levels leads to an increase in temperatures, which results in global warming. These high temperatures will lead to robust drying of the subtropics with temperatures of 20-350 because of CO2 suppressing precipitation in the long run.
Projected changes in central Asia show that there will be adverse drying, with temperatures rising from 20-400. In a period of four years (1998-2001), there was a 30% deficit in the annual precipitation in Central Asia. This led to four years of drought in the area, which led to the loss of livestock and food crops on farms. Current climate projections imply that there will be a similar water stress in the agricultural sector within the tropics and subtropics due to the climatic changes caused by CO2 in the near future.
In the year of 2003, Europe was adversely affected by extreme heat, with temperatures rising 3.60 above normal. This resulted in 30000-50000 people dying from the heat, as well as a high percentage drop in the yields of wheat and maize. There was also a tremendous drop in the fruit harvest. If current projections are accurate, similar conditions will be experienced in 2100.
Climatic changes have a great impact on food security. Higher temperatures will cause a subsequent decrease in yield. Higher mean temperatures raise the yield variance in mid-Latitudes. In addition to this, higher temperatures increase the rate of transmission of diseases. The increase of CO2 on a short-term basis increases the humidity of the atmosphere; thus, leading to an increase in yield. Further increase of CO2, in the long run, causes dryness; hence, the decrease in yield, and an increase in water stress.
Changes in climate also cause an increase in CO2, which boosts the growth of plants. This is seen in the C3 plants, whose growth rate is enhanced by an increase in CO2 in the atmosphere. However, an increase in carbon dioxide also affects the BGC and the soil pathology where the crops become more susceptible to diseases. In conclusion, the society should be prepared to adapt to changes in the environment because of the adverse effects of climate change.