World population can be defined as the total number of living humans on earth. The population has increased from 350 million in 1350 to 7.0 billion in 2010 (Wikipedia). The tremendous increase in world population has risen from 1960 to onwards mainly due to the provision of sanitation/medical facilities (Briben, 1980). Although studies by various agencies/departments quote different figures but it is mostly believed that the world population would be around about 17 billion people at the end of the 20th century. At present, on global basis, the birth rate is 142 million people against the death rate of less than 60 million on annual basis (Wikipedia).
From the findings of a study conducted in 2012, it is estimated that presently sex ratio is 1.01 male to 1 female on average basis across the globe, and on average basis, females have about 69 years and males 65 years age life span. The birth rate is 2.52 children per woman presently and about 1.29 billion people (18.06 per cent of world population) are earning even less than US $ 1.25 per day, so categorized as extremely poor (The Columbian Exchange report, 2012).
In Pakistan, population is around 185 million people presently, which accounts for 2.6 per cent of world population and ranked on number 6th globally on population basis. It is expected that population of Pakistan would be above 300 million in 21th century. Presently male to female ratio is 1.07 to 1, which is much high figure in comparison with overall world. The present birth rate is 3.8 children per woman and 23.76 infants are born against the death rate of 6.8 people per 1000 people. Average life expectancy is about 66.4 years per individual and the alarming situation is that around 60 per cent of population is categorized as poor, having only per capita income less than US $ 2.0 (BTI, 2014).
Food security can simply be defined as people having access to sufficient, safe and nutritious food. Arguments differ among the scientists about the global food security: some argue that enough food is present to feed every individual on earth, the only problem is distribution, and it is a possibility that this issue would be solved in future by improvement in transportation facilities and globalization. However, the opponents of above statement claim that it is impossible to feed over 17 billion people in 21th centaury with the current level of production as our resources are becoming limited. But apart from the above arguments, it is extremely difficult to predict about food security in 21th century as a lot of questions related to this issue are unsolved (WHO, 2014).
Apart from food security, some other most important challenges that could be in the 21th century are climate change, energy security, water scarcity, competition for land and many more. Clearing of forest/grass land has been started from the 13th century because of our demand for food/shelter. However, challenges in future are much more and scientists around the world are working to deal with upcoming issues. The result of most obvious effort was around 1975 in the world, when the Green Revolution in agriculture sector was occurred, per acre yield and crop quality were increased, artificial fertilizer use became most common and other factors also became vital (Evan, 2009).
Currently Pakistan is producing enough food for population, but wheat, pulses and edible oils are among the most vital agriculture imports. Despite of the availability of food, malnutrition is a major issue and around 1/3rd of population are malnourished. Natural energy resources are extremely limited and in future, these resources are expected to be completely exhausted. There would be huge burden on country economy to import a large number of commodities. Presently about 68 per cent people are living in rural areas, depend on agriculture and currently hold very small pieces of land. From the agriculture point of view, scarcity of water is a major issue and in future is going to be exacerbated. Among the suggested solutions to cope the challenges of food security, it is also recommended that population rate should be kept with the existing food resources and literacy rate should also be enhanced on emergency basis (Ahmad and Farooq, 2010).