According to the authors of a report that estimates human numbers will peak lower and sooner than originally predicted, the long-feared population bomb may not go off.
The study, commissioned by the Club of Rome, predicts that by the end of the century the world population will reach a high of 8.8 billion before the middle of the century, and then decline rapidly. The peak could come earlier if governments take progressive steps to raise average incomes and education levels.
Pressure on nature and the climate should start to relax once the demographic bulge is overcome, along with associated social and political tensions.
The authors caution that falling birthrates alone will not solve the planet's environmental problems, which are already serious at the 7.8 billion level and are primarily caused by excess consumption of a wealthy minority.
As countries like Japan and South Korea are finding that declining populations can cause new problems, such as a shrinking workforce and greater stress on healthcare associated with an ageing society.
The findings were cause for optimism but there was a catch, according to one of the authors of the report, Ben Callegari. This gives us evidence to believe that the population bomb won't go off, but we still have significant challenges from an environmental perspective. There needs to be a lot of work to address the current development paradigm of overconsumption and overproduction, which are bigger problems than population. Previous studies have painted a grimmer picture. Last year, the UN estimated that the world population would hit 9.7 billion by the end of the century and continue to rise for several decades after that.
The new projection, released on Monday, was carried out by the Earth 4 All collective of leading environmental science and economic institutions, including the Potsdam Institute for Climate Impact Research, Stockholm Resilience Centre and the BI Norwegian Business School. They were asked by the Club of Rome to follow its seminal Limits to Growth study more than 50 years ago.
It is based on a new methodology that incorporates social and economic factors that have a proven impact on the birthrate, such as raising education levels, particularly for women, and improving income. It sketches out two scenarios depending on the extent to which such policies are pursued.
In the business-as- usual case, it believes existing policies will be enough to limit global population growth to below 9 billion in 2046 and then fall to 7.3 billion in 2100. They warn that this is too late: although the scenario doesn't result in an overt ecological or total climate collapse, the likelihood of regional societal collapses rises throughout the decades to 2050, as a result of deepening social divisions both internal and between societies. The risk is particularly acute in the most vulnerable, badly governed and ecologically vulnerable economies. In the second, more optimistic scenario, with governments across the world raising taxes on wealthy to invest in education, social services and improved equality, it estimates human numbers could reach a high of 8.5 billion as early as 2040 and then fall by more than a third to about 6 billion in 2100. They think there will be a lot of gains for human society and the natural environment by the mid-century.
By 2050 greenhouse gas emissions are about 90% less than they were in 2020 and are still falling, according to the report. Carbon capture and storage of greenhouse gases is a way that the remaining atmospheric emissions of greenhouse gases are being removed from industrial processes. As the century progresses, more carbon is captured and stored, keeping the global temperature below 2 C above pre-industrial levels. The wildlife is starting to thrive again in many places.