The global population will begin to decline in the next 40 years and when it does, it will be difficult to reverse, according to a leading professor of biochemistry.
On Newstalk Breakfast this morning, UCC Emeritus Professor William Reville said depopulation "may well" be more of a threat to humanity than global warming.
“The conventional wisdom is that we have far too many people and we need to reduce them dramatically,” he said.
“What I am suggesting is that a lot of people, in fact, can be a good thing. This is a very complex matter that we need to think about. The evidence to date is that high populations and high numbers of people cause abundance and human thriving.
“Over the last 50 years and more, many parameters that we had associated with human flourishing and thriving, like access to clean air, access to water, access to food and human resilience in the face of natural disasters have improved to record levels despite burgeoning populations in the 20th Century and industrialisation.”
He said the global population is on course to start falling within 40 years.
“At the moment, the population of the world is 7.8 billion,” he said.
“That is going to increase in 2064, which is only 40 years away, to a peak of 9.7 billion and, at that point, world populations will for the first time in history begin to decline.
“By 2100 we will be down to 8.8 billion and still falling.
“Now the population at that stage will be greatly aged. In other worlds the population of elderly people will be quite high compared to now and compared to the population of younger people and people who will work and pay taxes to take care of the elderly.
“It will probably be very difficult to reverse this decline after 2100 because we have, in the developed world, been unable to reverse the decline in birth-rate.
“Many countries in the west have schemes to boost birth rates but they are not working.”
He said climate change is a dangerous development which “needs to be dealt with” – but said higher populations can bring more good than harm to the planet.
“There is an economic theory that won the Nobel prize, in the 1980s I think, called indigenous growth theory,” he said.
“It says that rapidly growing human populations bring about an awful lot of innovation and ingenuity that bless the world greater than human appetites damage it.
“So, you need certain numbers of people in order for humanity to thrive. I am not saying you let populations numbers go up ten and more billion but once populations start to decline it is very hard to reverse it and we need a certain level of population in order to keep ingenuity alive and to keep living standards alive.
“If we are going to defeat climate change, we need clever ideas. Humans are very clever but we need plenty of them to come up with the ideas so we need to become conscious of human populations and birth rates.”
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