8 billion people: Is population growth cause for hope or concern?

“The 360” shows you diverse perspectives on the day’s top stories and debates.

What’s happening

The world’s population reached an estimated 8 billion people on Tuesday, according to estimates from the United Nations.

It took just 12 years for the global population to increase from 7 billion to 8 billion, a period of unprecedented growth made possible by advances in public health, nutrition and economic development that have increased survival rates for children and allowed older generations to live longer than in the past.

“The milestone is an occasion to celebrate diversity and advancements while considering humanity’s shared responsibility for the planet,” U.N. Secretary-General António Guterres said.

The boom wasn’t distributed evenly around the world. Countries across Asia have accounted for the majority of the world’s growth since 2011. India alone added 180 million people and is projected to surpass China as the most populous nation sometime next year. Growth rates in most of Europe and North America have stagnated, with some countries even seeing their populations shrink.

Despite the speed with which the world added another billion people, demographers say the rate of population growth is actually slowing down. The U.N. projects that we’ll reach 9 billion people in 15 years and that the global population will ultimately peak at around 10.4 billion in the 2080s.

Why there’s debate

The question of how many people the Earth can sustain has been a source of heated debate for centuries. But our growing understanding of human-caused climate change has altered the stakes of that discussion in just a few years.

In the eyes of many experts, reaching what the U.N. is calling the “day of 8 billion” should be cause for major concern. They argue that a swiftly expanding population will only make it more difficult to reduce greenhouse gas emissions to the level that is needed to avoid the most catastrophic impacts of climate change. More people will also put extra strain on critical resources like food and water, which are primed to become more scarce amid extreme droughts and severe weather — especially in the parts of the world that are expected to grow most rapidly in the coming years. Some add that the most effective steps for reducing population growth, namely increased economic stability and improved reproductive autonomy for women, are worthy goals in and of themselves.

But others say these concerns are unfounded. They argue that focusing on the size of the population obscures the actual causes, and potential solutions, for climate change. The biggest driver of global emissions, they say, is the rate of consumption in rich countries — not the fact that low-income nations are adding more people. Some demographers also believe that an expanding population should be celebrated because it will help developing nations thrive economically and create more opportunities for innovation, collaboration and prosperity.

Perspectives

Pessimists

There may not be enough resources to sustain so many people

“Rapid population growth also means more people vying for scarce water resources and leaves more families facing hunger as climate change increasingly impacts crop production in many parts of the world.” — Dan Ikpoyi and Chinedu Asadu, Associated Press

Billions of additional people will put an enormous strain on the climate

“The hard fact is that in an age of climate breakdown, human numbers matter. And the ecological impact of another 2-3 billion humans will be immense.” — John Vidal, Guardian

A prosperous future is impossible without a sustainable population

“For if our stated goals of protecting the environment and leaving a better society for our children are truly sincere it is incumbent for us then to summon the courage to, openly and unapologetically, call out the greatest threats to both — human overpopulation and overconsumption.” — Robert P. Johnson, Santa Barbara Independent

We can curb population growth and advance women’s rights at the same time

“What if we could see our population peak earlier than projected and avoid ever having to know whether the planet can provide for 10 billion, 11 billion or 12 billion people? Achieving this wouldn’t necessitate inventing new technology or making massive monetary investments (relatively speaking). It would simply require making modern contraception available to everyone who wants it so that people are able to decide for themselves whether and when to become pregnant and give birth.” — Nicole Martin, San Diego Union-Tribune

The world isn’t doing enough to prepare for all these extra people

“No matter who is winning the debate about growth, we clearly aren’t planning for that growth particularly well.” — Howard V. Hendrix, San Francisco Chronicle

The most vulnerable places are also the least equipped to care for booming populations

“Often, the most vulnerable people in these countries face the greatest harms from climate change without having the resources to protect their health and environment. Population growth can deepen these iniquities.” — Maureen Lichtveld, Conversation MarketWatch

Optimists

Climate change is the result of overconsumption in rich nations, not a growing population

“Consumption of the resources that lead to carbon emissions matters more to climate change than population growth on its own, and those resources are primarily consumed by a relatively small number of wealthy people around the world. Change those consumption patterns — through a mix of better efficiency and new technologies that don’t emit carbon — and there’s room enough to keep growing the population without cooking the planet.” — Bryan Walsh, Vox

We already have the tools we need to sustain billions more people

“Declining biodiversity with increasing human numbers does not have to be a foregone conclusion. There are sustainable solutions out there for energy, agriculture, and how we build things. It’s just a matter of shifting perspectives, attitudes, and policies.” — Lauren Leffer, Gizmodo

The speed of population growth matters as much as the size itself

“When economists think about it, a large population is great for many different outcomes, but do you achieve that large population in 10 years or 100 years or 1,000 years? The longer it takes to get there, you can put in place the right structures in the system that will support that population.” — Alex Ezeh, global health expert, to BBC

More people equals more opportunity

“Every new human being comes to the world not only with an empty stomach, but also a pair of hands, and, more importantly, a brain capable of intelligent thought and new knowledge creation. In the process of economic development, human beings cause a lot of environmental damage, but the new wealth and knowledge that we create during that process also allow us to become better stewards of the planet.” — Marian Tupy, The Hill

Prosperity is always worth celebrating

“No one gets through life without sorrow, struggle, and disappointment, yet it is indisputably true that life on earth keeps getting better and better. In the aggregate, human beings have never been healthier, wealthier, safer, better fed, or better educated than they are right now.” — Jeff Jacoby, Boston Globe

Is there a topic you’d like to see covered in “The 360”? Send your suggestions to the360@yahoonews.com

Photo illustration: Yahoo News; photos: Getty Images