A series of research papers published in Nature Climate Change last week found that the human population could decline to less than half of its pre-industrial level of 9.4 billion people by 2100, according to a global projection.
“It’s really going to be really hard to keep on doing what we’re doing now,” says John R. Lott, a climate scientist at the University of Alabama in Huntsville.
“If you don’t get the population down to half of what it is today, you won’t have a chance.”
Lott and his colleagues estimate that a human population of 8.8 billion could live in the North Atlantic region of the United States in 2100.
If the current population growth rate holds for the rest of this century, the number of humans could fall to fewer than 3.5 billion, according the team.
“We have been thinking for quite some time that we might not be able to sustainably sustainably have human population growth in the future,” says Lott.
“But what we are seeing is that we can.”
LOTT AND THE BERMUDA DEVELOPMENT Team: Lott was a graduate student at the Scripps Institution of Oceanography at UC Berkeley in California in the 1970s and 1980s.
He is now a researcher at UC Santa Barbara.
Team: The researchers used data from the National Oceanic and Atmospheric Administration’s Landsat-2 satellite, which tracks the Earth’s surface and measures changes in vegetation.
LOTTO-2’s data record changes in land use patterns and vegetation cover.
They then used this information to calculate how many people could live and reproduce in a given area.
The team then compared the projected population growth for 2100 with this data and projected future populations to ensure that the population density in a particular area would not drop significantly.
In the end, they found that a population of around 3.3 billion people would be possible if all the world’s countries agreed to the international target of reducing the population by 1 billion to 2.5 million people by 2060.
But as of 2060, the projections show that this scenario is likely to be impossible.
“I think the world is going to need a very significant expansion of population,” Lott says.
“In a world with so much poverty and so much conflict and so many people living in the same place, I think we are not going to have that.”
LOTTI-2 data show that the planet is warming faster than at any time since 1900.
The researchers found that there was no correlation between the rate of warming and the number or the size of people living there.
“The only thing that can slow it down is population growth,” says study co-author Mark B. Smith, a geophysicist at Stanford University in California.
LOTT HAS BEEN PREDICTING THE RISE OF THE PLANET for over 30 years, and has published papers on climate change and human population dynamics.
But in 2005, he co-authored a paper predicting that the global population would increase by 1.3 to 2 billion between 2050 and 2100, based on a scenario in which population growth slows to less of a 2% rate.
The authors also assumed that the rate at which humans consume resources would continue to rise.
“This is a prediction that is still very much in the making,” says co-lead author Andrew J. Dessler, a physicist at Stanford.
“And it is an extremely hard prediction to make.”
But if human population is growing faster than anticipated, Lott predicts that we will face more global environmental and societal problems.
“At some point, we will have to look at whether the current trend of increasing population and increasing wealth is sustainable,” Lett says.
He says that in the long term, population growth will cause some people to die out while others will continue to live longer and prosper.
The paper, “How many people are going to survive the ice age?” appeared in the February 2017 issue of Nature Climate Chaos.
It was co-written by researchers from the University.