Population, pollution, food production: Can we find balance?
“The power of population is indefinitely greater than the power in the earth to produce subsistence for man”- Reverend Thomas Robert Malthus (1766–1834), British Scholar asserting that a finite earth would be unable to produce enough food to feed its ever-increasing population.
The population of the world currently is estimated to be 7.8 billion, an increase of about 5.3 billion people from a 1950 population of 2.5 billion.
The human population is predicted to reach 9.5 billion by 2050, which means that the increase in the number of people in the next 30 years would be approximately equal to the number of people living on earth in 1950.
This population explosion, coupled with the rapidly changing climate, post-harvest losses, the unequal availability of food resources around the world, environmental pollution and the huge reliance on chemicals for agriculture make the Reverend’s assertion a probable reality that may face the planet if necessary action is not taken soon.
The projections are that feeding a world population of about 9.5 billion people in 2050 will require raising overall food production by some 70 per cent between now and 2050. It translates to mean that food production in developing countries will need to almost double. This implies significant increases in the production of several key commodities.
For instance, we have to increase annual cereal production by almost one billion tonnes, meat production from 270 million tonnes to over 470 million tonnes; and overall, increase meat production in developing countries by up to 72 per cent.
In recent decades, growth in food production has been impressive; this is attributed to the development of disease-resistant varieties of staple crops; the increased use of chemical fertilisers and pesticides; continuous innovativeness in food production, including the use of plant growth-promoting bacteria and genetic engineering; and the expansion of irrigated agriculture.
Nevertheless, per capita food production actually declined in 51 developing countries, while rising in only 43 developing countries between 1979 to 1981 and 1996 to 1997.
Despite the successes, there is a huge ground for concern about the future. How much longer can food production keep pace with the population?
Population growth is concentrated in developing countries, with more than 90 per cent of births registered worldwide. Over the next 10 years, the population of the industrialised world will increase by only 56 million, while that of the developing countries will increase by more than 900 million.
The larger the population, the greater its impact on the environment and, therefore, on food production and environmental pollution.
Along with the growth of the human population, resources have been degraded on a large scale. At a time when we need to produce more food, the deterioration of the land through illegal mining and the misuse of chemicals are causing a sharp decline in agricultural production and sharply increasing pollution to an extent that the earth’s atmospheric, terrestrial and aquatic systems are no longer able to breakdown and tolerate the ever-increasing amounts of waste that human society produces, resulting in about 40 per cent of worldwide human deaths.
By far, agricultural activities and recently in Ghana, mining, have been the major contributors to environmental pollution. Apart from the noticeably direct effects of uncontrolled mining to the destruction of the forest and river bodies, such as, the drying up and changing of colour of rivers, the loss of fish and other living species in our river bodies and the destruction of land and forest cover; we must not lose sight of the very harmful effects of the heavy metals, mainly mercury, on our health and well-being.
Heavy metal contamination is usually described as Chemical Time Bomb because it is usually colourless and odourless and so happens unnoticed until it exceeds its environmental tolerance levels and results in serious ecological and health damage.
The effects of heavy metal pollution in general and specifically, mercury, on the health of humans are varied and often lethal. It causes birth defects resulting in irreversible developmental and neurological disabilities, a lower IQ, a shorter life expectancy and lowers the immune functions of the body. In adults, mercury ingestion causes various cancers, heart and lung diseases, skin diseases and affects the economic and social growth of communities and individuals.
So you live in the city or a community where illegal mining is not taking place so you are not bothered! Sorry, mercury emissions know no national or continental, talk of city boundaries. When emitted into the air, it travels thousands of miles in the atmosphere before eventually being deposited back to the earth in rainfall or dry gaseous form.
Once deposited, certain microorganisms can change it into methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish. More than one in seven deaths in the world is pollution-related. From contaminated sites alone, toxic pollution affects the health of more than 200 million people worldwide.
Overall, pollution kills three times more people than HIV, malaria and tuberculosis combined.
Saving earth, producing enough
So we need to increase food production on this finite earth while reducing and restoring contaminated environments – two activities that seem to be inversely related.
However, a modern scientific agricultural practice makes this possible by using certain bacteria generally referred to as Plant Growth Promoting Bacteria (PGPB) to simultaneously achieve these two objectives.
The use of the beneficial association between plants and bacteria to, one, help plants to grow well in the presence of deleterious soil factors because plant growth regulators produced by some bacteria are signal molecules that act as chemical messengers for growth and development regulators in the plant such that the widespread use of chemical fertilisers (which tend to increase environmental pollution) is reduced; two, so that higher biomass of plants could help accumulate and remove more heavy metals and three, for the bacteria themselves to act as biosorption of the contaminants and to change them into less toxic forms.
Could this approach help in remediating some of the heavy metal polluted sites in Ghana?
The writer is Soil and Water Management Expert. E-mail: