Human Evolution is Reaching the Limit of Growth that Earth Can Support

Since the Second World war there has been a dramatic and positive change in the human condition. Stephen Pinker’s book Enlightenment Now shows how world poverty is falling, life expectancy has increased and violence has declined. It’s been a golden age, most of us now live longer and have much more interesting and rewarding lives than our forebears. However, this success has resulted in an explosion of the number of people on Earth. The population of all successful animal species expands until it reaches its environmental limits, then declines. So far technological developments have allowed humans to overcome natural boundaries and become the most populous mammal species on Earth. World population has tripled since the end of the second world war, to 7.5 billion. It will reach 11 billion by the end of this century. There has also been an increase of at least 10-fold in economic output and a consequently dramatic  increase in the  use of Earth’s resources.

In historical times these effects of technological and population change were only apparent in specific locations and took centuries to emerge. Memetic evolution has accelerated so much that its effects are now seen within a decade and are felt everywhere across the globe. This is destabilising for society. How it will play out we are yet to see. New communities will form and new winners will emerge. However, there are three effects that are now inevitable in the next few decades as the consequence of actions already made: world population will increase, the environment will degrade and society will become more unequal.

Population growth is at its largest in the Southern hemisphere. The population balance of the globe is changing rapidly. By 2100, 6 of the largest countries in the world will be in Southern Africa.  Including such places as Nigeria, Ethiopia, Uganda and the Democratic republic of Congo. These are not rich places and this has many implications for the environment, stable government and emigration.

In the Northern hemisphere we face a different problem, an aging demographic. Put simply we are living longer. Whereas just 5-10 % of the population was over 65 in the 1950s, 25- 30% will be over 65 in the 21st century. This has enormous implications for the age of retirement, the working environment and health care costs. No government has yet resolved how this is to be addressed.

As to the environment, we are already seeing the effects of climate change, environmental degradation and a huge loss of biodiversity as we convert nature to arable land and pollute the environment. We have changed the Earth’s biosphere to suit our need.  97% of the biomass of all mammals on the Earth now consists of humans and their domesticated animals. Or to put it another way only 3 % of mammals are wild. Only 30% of birds are wild. The rest are chickens or other edible fowls.

Geologists have deemed that since the 1950s humans have so altered the planet that  we have entered a new geological epoch, the Anthropocene. Epochs usually last millions of years. If the climate scientists are right the Anthropocene will herald an era where environmental degradation will increasingly impinge on our lives.

After the Second World War, wealth disparities in the West declined. New technologies dramatically changed lifestyles, class barriers were broken down, women began to play a more directly important role in society and the advent of the welfare state improved the life of the less well off. Since about 1990, with the advent of globalisation, society has become more unequal again. Some democratic control over the negative aspects of capitalism has been lost. Executive salaries are sky- rocketing. The gig economy has created a new underclass of poorly rewarded labour. Multi-nationals are avoiding tax in tax havens. Wealth is becoming increasingly concentrated in the hands of a limited number of families. Just eight couples now own as much wealth as half the world’s population. Avoiding death duties in tax havens, a new breed of wealthy aristocracy is emerging.  Disparities in wealth last seen before the first world war are being recreated with a new class of globally mobile super-rich people. This is not just a moral issue.  In the Spirit Level Richard Wilkinson and Kate Picket express the view that unequal societies have higher levels of violence and crime, lower life expectancy and declining levels of mental health.

So far evolutionary forces have benefited mankind. But evolution is blind it does not always lead to improvement.  It appears that the easy years of thriving are now behind us; for every advance there is a setback. Recent forest fires, cyclones, floods, financial disasters, pandemics and revolutions have all taken their toll. We have reached a pivotal point in human history; it is now apparent that limits to the improvement in the human condition are being reached. It is no longer possible to pretend that it will be all right on the night. we are being bowled along by evolutionary forces to create a divided society that is destroying the planet.