The evolution, survival and advance of any species are dependent on the available resources. Left to nature, the population of each species will settle at a sustainable level. This may fluctuate according to unusual events like abundant years or disease, but will essentially remain stable. When circumstances change permanently a species will either adapt and flourish or fade away and become extinct.
The one species that has managed to bend this rule to its own advantage is the most advanced animal of all – Homo sapiens. In the beginning, around 60,000 years ago, it is estimated that there were no more than a million humans on earth. This population remained stable for millennia, limited by the restricted food supply available to primitive hunter-gatherers. But once man learned how to farm the land, rapid population growth followed.
Human intelligence and drive harnessed agriculture and technology to exploit nature’s bounty to such good effect that by the 14th century world population had reached 450 million. There were setbacks plague pandemics and natural disasters – but these proved to be no more than blips on the soaring population graph. By 1750 the figure was 791 million. In 1850 it had leapt to 1.26 billion, and by 1950 it had reached 2.52 billion. In 2050 Planet Earth will be inhabited by an estimated 9.75 billion people!
But is this huge population sustainable? Can all those mouths be fed, even using modern techniques like genetically modified crops? Will the continuing plunder of dwindling natural resources lead to catastrophic consequences for the environment that all living creatures depend on? These are questions that will perforce remain speculative until it becomes apparent whether or not human ingenuity can continue to support limitless population expansion. Common sense suggests the answer must be ‘no’, but the doom watch scenario indicates that this may not become apparent until Planet Earth has become irreparably damaged.
When: From the 1750s onwards
Toll: A large percentage of the world’s population already lives on or below the poverty line, with famine a regular occurrence, so the consequences of an additional three billion people arriving within the next 40 years are potentially catastrophic.
You should know: it is currently estimated that the world’s population increases by around 225,000 people every day. Ironically, developed nations, such as Japan and many European countries, are expected to suffer negative population growth as birth rates decline and longevity increases, meaning that smaller and smaller working populations have to support more and more elderly folk.