New evidence suggests volcanoes caused biggest mass extinction ever

New evidence suggests volcanoes caused biggest mass extinction ever
A volcanic eruption spells doom for a predatory gorgonopsid during the Permian Period. Credit: Margaret Weiner/UC Creative Services

Researchers say mercury buried in ancient rock provides the strongest evidence yet that volcanoes caused the biggest mass extinction in the history of the Earth.

Paleontologists with the University of Cincinnati and the China University of Geosciences said they found a spike in mercury in the geologic record at nearly a dozen sites around the world, which provides persuasive evidence that volcanic eruptions were to blame for this global cataclysm.

The study was published this month in the journal Nature Communications.

The eruptions ignited vast deposits of coal, releasing mercury vapor high into the atmosphere. Eventually, it rained down into the marine sediment around the planet, creating an elemental signature of a catastrophe that would herald the age of dinosaurs.

“Volcanic activities, including emissions of volcanic gases and combustion of organic matter, released abundant mercury to the surface of the Earth,” said lead author Jun Shen, an associate professor at the China University of Geosciences.

The  occurred at what scientists call the Permian-Triassic Boundary. The mass extinction killed off much of the terrestrial and marine life before the rise of dinosaurs. Some were prehistoric monsters in their own right, such as the ferocious gorgonopsids that looked like a cross between a sabre-toothed tiger and a Komodo dragon.

The eruptions occurred in a volcanic system called the Siberian Traps in what is now central Russia. Many of the eruptions occurred not in cone-shaped volcanoes but through gaping fissures in the ground. The eruptions were frequent and long-lasting and their fury spanned a period of hundreds of thousands of years.

“Typically, when you have large, explosive , a lot of mercury is released into the atmosphere,” said Thomas Algeo, a professor of geology in UC’s McMicken College of Arts and Sciences.

“Mercury is a relatively new indicator for researchers. It has become a hot topic for investigating volcanic influences on major events in Earth’s history,” Algeo said.

Researchers use the sharp fossilized teeth of lamprey-like creatures called conodonts to date the rock in which the mercury was deposited. Like most other creatures on the planet, conodonts were decimated by the catastrophe.

The eruptions propelled as much as 3 million cubic kilometers of ash high into the air over this extended period. To put that in perspective, the 1980  of Mount St. Helens in Washington sent just 1 cubic kilometer of ash into the atmosphere, even though ash fell on car windshields as far away as Oklahoma.

In fact, Algeo said, the Siberian Traps eruptions spewed so much material in the air, particularly greenhouse gases, that it warmed the planet by an average of about 10 degrees centigrade.

The warming climate likely would have been one of the biggest culprits in the mass extinction, he said. But  would have spoiled many bodies of water and raised the acidity of the global oceans. And the warmer water would have had more dead zones from a lack of dissolved oxygen.

“We’re often left scratching our heads about what exactly was most harmful. Creatures adapted to colder environments would have been out of luck,” Algeo said. “So my guess is temperature change would be the No. 1 killer. Effects would exacerbated by acidification and other toxins in the environment.”

Stretching over an extended period, eruption after eruption prevented the Earth’s food chain from recovering.

“It’s not necessarily the intensity but the duration that matters,” Algeo said. “The longer this went on, the more pressure was placed on the environment.”

Likewise, the Earth was slow to recover from the disaster because the ongoing disturbances continued to wipe out biodiversity, he said.

Earth has witnessed five known mass extinctions over its 4.5 billion years.

Scientists used another elemental signature—iridium—to pin down the likely cause of the global mass extinction that wiped out the dinosaurs 65 million years ago. They believe an enormous meteor struck what is now Mexico.

The resulting plume of superheated earth blown into the atmosphere rained down material containing iridium that is found in the geologic record around the world.

Shen said the mercury signature provides convincing evidence that the Siberian Traps eruptions were responsible for the catastrophe. Now researchers are trying to pin down the extent of the eruptions and which  in particular were most responsible for the mass die-off, particularly for land animals and plants.

Shen said the Permian extinction could shed light on how global warming today might lead to the next mass extinction. If global warming, indeed, was responsible for the Permian die-off, what does warming portend for humans and wildlife today?

“The release of carbon into the atmosphere by human beings is similar to the situation in the Late Permian, where abundant carbon was released by the Siberian eruptions,” Shen said.

Algeo said it is cause for concern.

“A majority of biologists believe we’re at the cusp of another mass extinction—the sixth big one. I share that view, too,” Algeo said. “What we should learn is this will be serious business that will harm human interests so we should work to minimize the damage.”

People living in marginal environments such as arid deserts will suffer first. This will lead to more climate refugees around the world.

“We’re likely to see more famine and mass migration in the hardest hit places. It’s a global issue and one we should recognize and proactively deal with. It’s much easier to address these problems before they reach a crisis.”

So many animals are going extinct that it could take Earth 10 million years to recover

skulls bones extinction
It took the Earth 10 million years to recover from the mass extinction that killed the dinosaurs.

  • Many scientists argue that the planet seems to be undergoing a sixth mass extinction, with global fauna experiencing a major collapse in numbers.
  • The five previous mass extinctions were caused by catastrophic events like asteroid collisions. This time, human activities are to blame.
  • Deforestation, mining, and carbon dioxide-emissions, which cause the Earth to warm, are driving species around the world to extinction.
  • A new study shows that the last time the planet experienced a mass extinction — which wiped out the dinosaurs — it took Earth’s species 10 million years to recover.

Some 65 million years ago, an asteroid just six miles wide struck the planet. The resulting cloud of dust and debris that funneled into the atmosphere blocked sunlight for several weeks, while earthquakes, landslides, and tsunamis wreaked havoc on what is now the Americas.

When all was said and done, the Tyrannosaurus rex and its Saurichian compatriots had all died out, along with 75% of the planet’s species.

Today, another force is driving Earth towards its next extinction event. Human-driven changes to the planet are hitting global species on multiple fronts, as hotter oceans, deforestation, and climate changedrive floral and faunal populations to extinction in unprecedented numbers. As much as half of the total number of animal individuals that once shared the Earth with humans are already gone, a clear sign that we’re on the brink, if not in the midst of, a sixth mass extinction.

A new study published in the journal Nature Ecology and Evolution reveals that it took the planet around 10 million years to recover from the mass extinction that wiped out the dinosaurs.

That’s bad news if we want to get Earth’s currently dipping biodiversity back on track.

dinosaurs asteroid strike impact extinction event global disaster shutterstock_408550594
The asteroid that killed the dinosaurs left an impact crater 110 miles wide.

“From this study, it’s reasonable to infer that it’s going to take an extremely long time — millions of years — to recovery from the extinction that we’re causing through climate change and other methods,” co-author of the new study Andrew Fraass said in a press release.

“Biodiversity losses won’t be replaced for millions of years, and so when you imagine extinctions in coral reef ecosystems, or rain forest ecosystems, or grasslands, or wherever, those places are going to be less diverse essentially forever, as far as humans are concerned,” Chris Lowery, paleobiologist and co-author of the new study, told Business Insider.

An evolutionary ‘speed limit’

Scientists have long argued that the 10-million-year time frame for global biodiversity to properly rebound is a feature of all five of Earth’s mass extinctions, but for the first time, there’s now fossil evidence of that delay.

In order to determine how quickly Earth’s biodiversity recovered after the mass extinction event 65 million years ago, Lowery and Fraass examined tiny single-celled organisms called planktic foraminifera that are abundant in the fossil record (there are some 4,000 species still alive today, according to the University of California Museum of Paleontology at Berkeley).

A photomicrograph showing 10 species of foraminifera, a type of plankton.
 United States Geological Survey/l Randolph Femmer

In an ecosystem, each animal and plant species occupies a unique niche — the specific part of an ecosystem that an organism inhabits. Following a mass disappearance of species, one might think that these niches would still be available for adaptable extinction survivors to then take over. But according to Lowery, that’s not the case.

“Niches and the organisms that fill them are basically inseparable, so a mass extinction destroys niches as it destroys species,” he said. The new study shows that these complex ecological niches need to be rebuilt before species diversity can fully recover, and that’s the reason behind the delay.

An artist’s interpretation of the sea floor after the mass extinction that wiped out the dinosaurs. The three hair-covered forms (left) represent species of plankton that survived.
 The University of Texas at Austin Jackson School of Geosciences/John Maisano

“What’s interesting is that there seems to basically be a hard speed limit for this process, and it takes about 10 million years to complete,” Lowery added.

The study authors wrote that the generation of new ecological niches following a mass extinction means that the world that re-populated after the asteroid strike was a “wholly new” ecosystem, “rather than a return to a mirror version” of the what the world was like before the extinction.

There’s consensus on one aspect of the extinction trend: it’s all our fault

“It’s astounding to me that humans have the capacity to influence the earth system, in this case the biosphere, on truly geologic timescales,” Lowery said. “I think this really underscores how important conservation is.”

skeleton deer
The disappearance of essential species from local ecosystems will cause cascading effects that ripple through the entire system.
 Michael Kinnaman/Getty

Scientists are still arguing about whether the Earth is truly in the midst of another mass extinction.

“We have to work to save biodiversity before it’s gone. That’s the important takeaway here,” Lowery said.

There is consensus on one aspect of the extinction trend, however: Homo sapiens are to blame. According to a 2014 study, current extinction rates are 1,000 times higher than they would be if humans weren’t around.

“It’s incredible that humans have the capacity to damage the biosphere so severely that it will take millions of years to recover,” Lowery said.

SEE ALSO: Insects are dying off at record rates — an ominous sign we’re in the middle of a 6th mass extinction

The Insect Apocalypse Is Coming: Here Are Five Lessons We Must Learn

In a new report, scientists warn of a precipitous drop in the world’s insect population. We need to pay close attention, as over time, this could be just as catastrophic to humans as it is to insects. Special attention must be paid to the principal drivers of this insect decline, because while climate change is adding to the problem, food production is a much larger contributor.

The report, released by researchers at the Universities of Sydney and Queensland and the China Academy of Agricultural Sciences, concluded that 40 percent of insect species are now threatened with extinction, and the world’s insect biomass is declining at 2.5 percent a year. In 50 years, the current biomass of insects could be cut in half. Such a sharp decline could trigger a “catastrophic collapse of nature’s ecosystems.”

We have, it appears, a lot to learn to avert the looming insect apocalypse. Here are five critical lessons.

1. Small things tend to get overlooked.

While the volume of scientific research on the threat of species extinction is growing rapidly, most of the focus has been on the declining population of fish and large mammals. Compared to larger species, insect species and their populations get very little attention. In making their report, the authors conducted a comprehensive review and found 73 historical studies of insect decline. That’s a tiny fraction of the reports written about the population loss of larger species. Yet arthropods (insects, spiders, crustaceans) account for about half of the world’s animal biomass — 17 times more than humans.

2. Small things matter.

When it comes to endangered species, large mammals get all the headlines, but insects are essential to the underlying web of life on which larger creatures depend. About 60 percent of bird species rely upon insects as a primary food source, and birds consume up to 500 million tons of insects every year. Moreover, it is estimated that 80 to 90 percent of wild plants depend upon insects for pollination. And while some insects feed off domesticated crops, other insects help to keep pest populations under control. A 2006 study estimated that insects in the U.S. provided “ecosystem services” worth $57 billion a year. These include pest control, crop pollination, and serving as a vital food source for fish and small wildlife.

3. Environmental degradation is accelerating.

Climate change, pollution and the ongoing destruction of forests, wetlands, reefs and other vital habitats are taking an ever-increasing toll on nature. And it’s not just insects; environmental degradation is accelerating and rapidly diminishing non-human populations, including birds, fish and large undomesticated mammals. The World Wildlife Fund estimates that wildlife populations, on average, have declined 60 percentsince 1970. The International Union for Conservation of Nature now classifies 26,000 species as threatened with extinction, and leading scientists publicly warn that a “sixth mass extinction” has commenced.

4. It’s not just our greenhouse gas emissions …

No one should underestimate the impact that rising greenhouse gas emissions are having on the web of life, but the authors of the insect report indicate that the three largest drivers of insect depopulation are, in order of importance: 1) habitat loss attributable to agriculture and urbanization; 2) pollution, mainly caused by pesticides and fertilizers and; 3) the introduction of invasive species. Climate change, which many believe is the largest driver of ecological ruin, ranked only fourth as a driver of insect decline.

5. … It’s us.

The principal drivers of insect extinction have a common denominator. Simply put, the insect decline, in one form or another (including climate change), is attributable to humans. Our growing numbers and our appetites are driving insects to extinction. There is no letup in sight. World population, presently 7.6 billion, is expected to reach nearly 10 billion by mid-century, and the world’s middle class is expected to rise at an even faster rate. Our demand for food, and particularly our appetite for meat products, is leaving less room for other creatures, including insects.

Humans already use a land mass about the size of South America to produce crops for consumption and an area nearly the size of Africa to feed our livestock. Add in the pesticides and fertilizers that we depend upon to boost crop yields, and it’s no wonder that insect populations are suffering mightily.

The authors of the report on insect loss warned that, “Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades.” Curbing our reliance on pesticides and fertilizers could reduce the loss of insects, but it’s our ever-growing need for higher crop yields that has given rise to their use in the first place. Given enough time and capital investments, the farmers of the world might be able to adopt sustainable farming practices without reducing crop yields, but we may not have the luxury of time.

To avoid insect apocalypse, we need to reduce the size of our agricultural footprint. That should begin by preventing runaway population growth and the unsustainable food demand that would go with it. We should increase our support for family planning programs that help to prevent unplanned pregnancies at home and abroad. At present, nearly 40 percentof the pregnancies in the world are unintended. We should also commit to reducing our meat consumption, particularly beef. Meat-based dietsrequire the use of far more land and water and result in much bigger environmental impacts — from greenhouse gas emissions to land degradation — than plant-based diets do.

If insects head toward precipitous decline and extinction, humans can’t be far behind. We need to advance our thinking about insects, their importance and what can be done to save them.

This article was produced by Earth | Food | Life, a project of the Independent Media Institute.

Humans are the villain in Netflix’s new series ‘Our Planet’

The new Netflix series Our Planet begins, of all places, on the moon. Rest assured that the camera soon reveals a view of our tiny, stunning home planet, where it stays grounded for the next eight episodes. It’s an exercise in perspective. As the astronauts on the Apollo mission first found out 50 years ago, that distant view helps you see that our fragile planet has limits. It’s a precious object.

David Attenborough, the 92-year-old naturalist famous for his warm, authoritative half-whisper, immediately clears up any concerns that Our Planet is your typical nature show. As a polar bear and its cub amble across icy terrain, Attenborough explains that wildlife populations have plunged, on average, by 60 percent over the last 50 years. “For the first time in human history,” he says, “the stability of nature can no longer be taken for granted.” (Cue melting ice crashing into the sea.)

Our Planet takes you on a trip to every type of landscape and seascape on Earth. The icy Antarctic, the deep jungle in Borneo, the Arabian desert, the coral reefs of Australia. It has all the familiar scenes of frolicking wildebeest, feasting flamingos, and weird bird mating dances you’re used to seeing from the Planet Earth canon, but unlike its predecessors, it’s punctuated by frequent reminders that global catastrophe is unfolding. Half of the world’s shallow coral reefs have already perished, and the rest could disappear within a few decades. Each year we lose nearly 15 million hectares of tropical forest, an area larger than Illinois. And by 2040, the Arctic Ocean will be mostly ice-free.

“We are entering a new geological era, not as in the past when changes happened over millions of years, not even over thousands of years or centuries, but within decades — within my lifetime,” Attenborough writes in the coffee table book that accompanies the documentary. “These changes are as rapid and as great as when the planet was struck by an asteroid.”

The show is part of an emerging genre of wildlife documentary that tackles conservation and climate change in tandem. The new National Geographic seriesHostile Planet, narrated by Bear Grylls of Man vs. Wild, portrays animals toughing out searing heat, parched landscapes, and fractured ice in the most extreme environments on Earth. Attenborough also narrated a documentary coming out this spring called Climate Change: The Facts on BBC One.

For a show about our shifting environment, it’s curious that Our Planet’s carefully constructed opening — and the entire first episode — fails to mention “climate change” by name. (The later episodes don’t shy away from the phrase.) The opening episode, which explains how far-flung habitats on Earth are all connected, was possibly the hardest one to get right, said Alastair Fothergill, the series producer, in an email.

“We felt it critical for the whole series that the balance between entertainment, education, and environmental messaging was just right,” he said. “We need millions of people worldwide to watch this series, and we need to ensure we do not alienate the audience.”

It’s a tough task, since the episodes are filled with sobering facts. Dismal statistics spell out the fate of the unsuspecting animals living their lives onscreen. As you watch fuzzy orangutans swing between trees in northern Sumatra, for example, Attenborough says you could be looking at the last ones to live in the wild. Deforestation has led to the demise of 100 orangutans a week, he says, by turning their jungle home into expanses of palm trees grown for their oil.

Those responsible for all this forest-clearing, poaching, and destruction spend most of the series offstage. The only time people show up is in the “Coastal Seas” episode, which illustrates overfishing by showing fishermen at work in their boats. Only a few images of human activity made the cut, Fothergill said. But they’re all the more powerful as a result.

Grace Frank / Silverback / Netflix

The episodes come with mini science lessons. You’ll learn how Arctic sea ice acts as a “protective white shield” for the planet, keeping the earth cool by reflecting the sun’s energy back into space, and that Earth is losing that shield, a feedback loop that accelerates warming. You’ll also learn about the science of coral bleaching and the amazing carbon-sucking powers of forests and seagrass.

And, as in any good nature series, you’ll probably find one thing that blows you away. For me, in Blue Planet II, it was the toxic lakes inside the ocean. In Our Planet, it’s that the underside of that pristine-looking Antarctic sea ice is covered in algae, forming the base of an ecosystem that Attenborough describes as “the polar equivalent of the great grasslands.”

It’s not all grim. Siberian tigers are slowly coming back from the brink of extinction; blue whales and humpback whales have made remarkable recoveries thanks to international agreements around saving them. It’s a reminder of what human cooperation is capable of accomplishing when we’re actually able to cooperate … or when we just leave things alone.

The final episode tells the story of Europe’s strangest wildlife recovery. It takes place in the radioactive exclusion zone around Chernobyl, Ukraine. Twenty years after 100,000 people evacuated, the fallout zone held animal populations similar to those in the wilder parts of Europe, Attenborough says; now, wildlife populations there are more profuse than in the surrounding nature preserves or national parks. Bison, elk, and red deer wander among the ruins of buildings as wolves and lynx patrol the forest that’s regrown in the former suburbs.

“They may be radioactive,” the Our Planet book says, “but they are having a ball.”

Many sharks closer to extinction than feared

: Red List

Marlowe Hood

Agence France-Presse
Paris / Mon, March 25, 2019 / 09:00 pm

A picture of mako shark. Seventeen of 58 species evaluated were classified as facing extinction, the Shark Specialist Group of the International Union for the Conservation (IUCN) said late Thursday in an update of the Red List of threatened animals and plants.

Human appetites are pushing makos and other iconic sharks to the brink of extinction, scientists warned in a new assessment of the apex predator’s conservation status.

Seventeen of 58 species evaluated were classified as facing extinction, the Shark Specialist Group of the International Union for the Conservation (IUCN) said late Thursday in an update of the Red List of threatened animals and plants.

“Our results are alarming,” said Nicholas Dulvy, who chairs the grouping of 174 experts from 55 countries.

“The sharks that are especially slow-growing, sought-after and unprotected from overfishing tend to be the most threatened.”

That category includes the shortfin mako, whose cruising speed of 40 km/h (25 mph) — punctuated by bursts of more than 70 km/h — makes it the fastest of all sharks.

Along with its longfin cousin, the two makos are highly prized for their flesh and fins, considered a delicacy in Chinese and other Asian culinary traditions.

“Today, one of the biggest shark fisheries on the high seas is the mako,” Dulvy told AFP. “It is also one of the least protected.”

In May, nations will vote on a proposal by Mexico to list the shortfin mako on Appendix II of CITES, the Convention on International Trade in Endangered Species.

An Appendix II status would not ban fishing or trade, but would regulate it.

Six of the species reviewed were listed as “critically endangered,”
three for the first time: the whitefin swellshark, the Argentine angel shark, and the smoothback angel shark.

Eleven others were classified as either “endangered” or “vulnerable” to extinction.

The IUCN’s shark group is conducting a two-year review of more than 400 species of sharks.

Read also: ‘They’re all dead’: 110 captive sharks in Karimunjawa die mysteriously

For land animals, conservation biologists focus on population size and geographic range in assessing extinction threat.

For sharks and other marine animals they use another approach, looking instead at how quickly populations decline.

‘Way worse than thought’

But that requires a benchmark, especially for pelagic — or open ocean
— species, Dulvy explained.

Only within the last 10 years have scientists been able to establish one, partly with the help of tuna fisheries that began to keep tallies of sharks by-catch.

“A decade on, we now know that the situation is way worse than we ever thought,” Dulvy said.

Ironically, fisheries management organisations doing a better job policing tuna catches has increased the incentive for fishermen to target sharks for extra income.

“In the Indian Ocean” — along coastlines in the Arabian Sea and the Bay of Bengal — “the tuna fishery is really a shark fishery with tuna by-catch,” Dulvy said.

In light of its new findings, the Shark Specialist Group is calling for “immediate national and international fishing limits, including complete bans on landing those species assessed as ‘endangered’ or ‘critically endangered’,” said Sonja Fordham, deputy chair of the group and an officer at The Ocean Foundation.

Sharks have lorded over the world’s oceans for some 400 million years, playing a critical role in global food chains.

But the top-level predators have proven especially vulnerable to human
predation: they grow slowly, become sexually mature relatively late in life, and produce few offspring.

The greeneye spurdog — newly classified as endangered — has a gestation period of nearly three years, the longest in the animal kingdom.

A 2013 peer-review study estimated that upward of 100 million sharks are fished every year to satisfy a market for their fins, meat, and liver oil.

More than half of shark species and their relatives are categorised as threatened or near-threatened with extinction.

War, famine and drought: More women say they won’t have children because of climate change

Laura Formisano says she has never felt a huge desire to have children, but she always presumed that would change.

Now, married for seven months, she feels climate change could make the planet so uninhabitable, she’s not sure she can bring herself to become a parent.

“It almost feels like a con, to bring a child into the world when it’s probably not going to be a place we’re really going to want to live,” says Formisano, 30, who manages a co-working space in Los Angeles.

Is the future simply too horrific to bring children into? Some couples, frightened by the prospect of droughts, wars, famines and extinctions brought on by climate change, are making that decision.

A Facebook group for women to discuss the idea launched this month, and it’s already winning over supporters in Europe and the United States. Conceivable Future, a U.S.-based group, has held more than 50 house parties in 16 states in recent years where women worried about global warming discuss  forgoing motherhood.

“There are around 70 new signups in the last seven days,” says Blythe Pepino, who helped create the #BirthStrike Facebook page.

The reasons women come to this decision are many and varied, but they tend to focus on what the women call a clear-eyed view of the changes a warming planet are likely to bring.

For some, the consequences are all too easy to imagine.

Eight years ago, a massive tornado devastated Christy LeMaster’s hometown of Joplin, Missouri. The monster storm was 22 miles long and at times a mile wide. It killed 158 people, injured 1,150 others and destroyed almost 7,000 homes. LeMaster’s family was OK, but she knows many people who weren’t.

“The reality is, they’re still rebuilding. Tornadoes on that scale are only supposed to happen every 50 or 60 years. When catastrophes on this scale start happening more often, what does life look like?” says the 38-year-old, who now lives in Chicago and curates public programs at the Museum of Contemporary Art Chicago.

While LeMaster says she’s not someone who has “a deep drive for child-bearing,” she’d long thought she would have children in her life. But with climate change  stoking the prospect of serious economic dislocation and fights over resources, “I feel even more scared now,” she says.

“If I’m honest with myself, I don’t know what water will look like in 10 years. What temperatures will look like in 15, or even food distribution,” she says.

A congresswoman asks: Is it OK to have kids?

New York’s popular Democratic Rep. Alexandria Ocasio-Cortez, 29, who is pushing for a Green New Deal to help fight climate change, broached the topic last month on Instagram.

“There’s scientific consensus that the lives of children are going to be very difficult, and it does lead, I think, young people to have a legitimate question — is it OK to still have children?” she said during a video streaming live from her kitchen.

Newlywed Luci Kade, of Atlanta, says her friends don’t talk about climate change much, which she attributes to the shift “happening on a larger and slower scale than we can comprehend.” But the trends are clear to her, and she doesn’t feel she can ignore them.

“It’s really important to respond to the climate change crisis by actually treating it like a crisis. One way you do that is you don’t go on with business as usual,” says Kade, 28.

The forest fires, hurricanes and other drastic weather events in recent years give her pause about what kind of world humanity will be living in 30 or 40 years from now.

Because of that, she and her wife have decided to adopt. Kade works in the foster care system, so she knows how many children there already are who need families.

“It just feels morally and ethically irresponsible to have my own children,” she says.

Climate change poses a real danger

There’s growing concern over the dangers climate change poses, with people in 13 of 26 countries polled by the Pew Research Center last month saying it is the top international threat.

And women more than men are worried about it. In the United States, 66 percent of women cited global climate change as a major threat to the nation, while only 51 percent of men did.

Such fears are based on solid science. Last October, the United Nations’ Intergovernmental Panel on Climate Change warned that mankind has 12 years to act to avoid “rapid, far-reaching and unprecedented changes in all aspects of society.” Even in the best scenarios, it said, the world will  face more extreme weather events — more wildfires, more droughts, more floods, rising sea levels and the loss of almost all coral reefs.

Whether that’s affecting women’s family planning isn’t known. The U.S. birthrate has been falling for years, and in 2017 was just 60.3 births per 1,000 women — the lowest fertility rate since the Centers for Disease Control and Prevention began keeping records in 1909. Causes such as women marrying later, worries about the economy and the difficulty of finding affordable child care have all been suggested.

No one has yet polled American women to ask if climate change is a part of this. But in Australia, a survey of 6,500 women released last month found that 22 percent of  respondents in their 30s said they were considering having no more children, or not to have children at all, because of climate change.

“It would break my heart having this child that you love, that you nurture and raise, and then you’re leaving them behind with a ‘Well, good luck! Things aren’t going to get better, you’re on your own,’ ” says Formisano, of Los Angeles.

Her husband agrees, she says. “He always says, ‘We’re too many. We don’t need to have this many people on Earth.’ “

Feeling like ‘part of the solution’

Forgoing children is a stance many women, and some men, in the climate movement have long thought about, but the first organized discussions appear to have happened in 2014. That was when Meghan Kallman and Josephine Ferorelli met at a concert in New Hampshire.

Both 30 at the time, they began talking about climate change and “within five minutes” came to the topic of not having children because of their worries about just how bad things seemed likely to get, they say.

Despite this being a top-of-mind concern for both of them, they’d never found a place to share their fear before. After talking most of the night, they decided that they couldn’t be the only ones wrestling with these concerns. They launched house parties where people could talk about the ethics of family planning and climate change.

Kallman, a professor of international development at the University of Massachusetts, Boston, and Ferorelli, a climate activist in Chicago, acknowledge that whatever happens in the future, as two white women in the United States, it won’t be as difficult for them as it will for women elsewhere in the world. Even so, they’re consumed by “the knowledge that what we’re facing is so much worse than we imagine,” says Kallman.

Ryanne Hoogeboom, now 38, attended one of the early events. She lives in Albuquerque with her 4-year-old daughter, Kit. While she loves her daughter dearly, she and her partner have decided not to have any more children. “He’s in the same camp I am,” she says.

Hoogeboom says she made many changes in her life, including traveling less and moving into a smaller home, as she  realized she “was part of the problem.” She’s now gone back to college to get her bachelor’s degree, while she works as a file clerk and tries to raise her daughter “so she’ll be part of the solution.”

When Hoogeboom explains to relatives why Kit doesn’t have any siblings, she gets confused looks if she mentions climate change.

“People don’t really understand what I’m so freaked out about. ‘It’s going to get figured out,’ is their attitude,” she says.

Hanna Scott, 23, is one of the people who say it won’t get figured out. “We’re on a trajectory towards a real hellscape,” she says.

A resident of Bicester, England, she heard about the #BirthStrike Facebook group in early March, finally finding common ground on a topic that had been gnawing at her.

At 23, she sees things getting dicey in her own lifetime, much less  a child’s. Even the idea of a quiet retirement is inconceivable to her.

“The climate will have changed, sea level will be rising, people will be migrating, it will cause huge geopolitical issues,” she says.

Although she’s not seeing anyone now, she’s clear this would be something she’d bring up if she started a serious relationship.

“I fully respect that my partner might have a different perspective. If my partner really, really wanted a child, then I guess adoption is potentially in the cards. But more likely I don’t think the relationship would continue,” she says.


On Facebook, #BirthStrike is a closed group. To join, women must agree to a declaration that says they won’t bear children “due to the severity of the ecological crisis.” Participants also must state they are in compassionate solidarity with all parents, celebrating their choices and not judging those who do bear children. So far, 225 women have signed up.

Pepino, one of the founders, says she wishes her vision of the future wasn’t so full of famine, violence and global wars over resources. “I’m 32 and I absolutely love my partner and I want his kid so badly. But I just can’t figure out how I would do that,” she says.

For some, that vision of the future comes just as their biological clocks are ticking the loudest.

“Up until about two years ago I said I didn’t want children anyway. Then I started to be drawn to the idea of motherhood at the same time I was becoming really aware of what was going on in the world,” says Jen Witts, 38, in Bristol, England.

“I thought, ‘How could I bring a child into the world knowing what we face and how bad it’s going to get?’ ”

The discussion didn’t go well with her family. “My mother is absolutely devastated, she says it’s the worst thing I’ve ever done because she simply can’t understand it,” Witts says.

Not all mothers are distressed. Lori Day, 55, in Newberry Port, Massachusetts, has come to terms with her 27-year-old daughter not having kids, even though she had been “so looking forward to having grandchildren.”

Mostly her daughter just “doesn’t have that biological clock ticking, but she also doesn’t believe it’s going to be a world to bring a child into,” Day says. 

Day sees her daughter’s point. “I have solar panels on my house, I drive a hybrid car. But deep down, I think it’s too late. I don’t know what the speed is at which things are going to unravel — but I believe it will affect the end of my life and it will affect her when she’s my age,” she says. 

Not population control

To be sure, the decision to not have children isn’t a full-on movement; it’s more a discussion that’s beginning to bubble up in people’s consciousness. And organizers are clear that this is not about population control.

“It’s not like my choosing to have a kid or not is going to solve the climate crisis,” Kallman says.

The goal isn’t to get women and men to pledge not to have children, but instead to provide a place to talk about a topic that most people don’t want to discuss even as humanity barrels into what they believe will be a dark and dystopian future.

“It’s not anybody’s answer to this question that matters, it’s the fact that people are even having to ask this question. That’s what’s messed up,” Ferorelli says.

12 signs we’re in the middle of a 6th mass extinction

dead fish
A skeleton of a fish lies forgotten on the dry bed of Lake Peñuelas outside Santiago, Chile.
 Eliseo Fernandez/Reuters
  • The planet is undergoing a sixth mass extinction, the sixth time in the history of life on Earth that global fauna has experienced a major collapse in numbers.
  • Historically, mass extinctions have been caused by catastrophic events like asteroid collisions. This time, human activities are to blame.
  • The primary culprits are deforestation, mining, and carbon-dioxide emissions, which cause the planet to heat up.
  • As a result, insects are dying off at record rates, animal species are experiencing “ biological annihilation,” and invasive aliens are driving native species to extinction.

The phrase “mass extinction” typically conjures images of the asteroid crash that led to the twilight of the dinosaurs.

Upon impact, that 6-mile-wide space rock caused a tsunami in the Atlantic Ocean, along with earthquakes and landslides up and down what is now the Americas. A heat pulse baked the Earth, and theTyrannosaurus rex and its compatriots died out, along with 75% of the planet’s species.

Although it may not be obvious, another devastating mass extinction event is taking place today — the sixth of its kind in Earth’s history. The trend is hitting global fauna on multiple fronts, as hotter oceans, deforestation, and climate change drive animal populations to extinction in unprecedented numbers.

Read more: Insects are dying off at record rates — an ominous sign we’re in the middle of a 6th mass extinction

2017 study found that animal species around the world are experiencing a “biological annihilation” and that our current “mass extinction episode has proceeded further than most assume.”

Here are 12 signs that the planet is in the midst of the sixth mass extinction, and why human activity is primarily to blame.

Insects are dying off at record rates. Roughly 40% of the world’s insect species are in decline.

Insects are dying off at record rates. Roughly 40% of the world's insect species are in decline.
Insects are going extinct eight times as fast as mammals, birds, and reptiles.
Hillary Kladke/Getty Images

A 2019 study found that the total mass of all insects on the planets is decreasing by 2.5% per year.

If that trend continues unabated, the Earth may not have any insects at all by 2119.

“In 10 years you will have a quarter less, in 50 years only half left, and in 100 years you will have none,” Francisco Sánchez-Bayo, a coauthor of the study, told The Guardian.

That’s a major problem, because insects like bees, butterflies, and other pollinators perform a crucial role in fruit, vegetable, and nut production. Plus, bugs are food sources for many bird, fish, and mammal species — some of which humans rely on for food.

Earth appears to be undergoing a process of “biological annihilation.” As much as half of the total number of animal individuals that once shared the Earth with humans are already gone.

Earth appears to be undergoing a process of
The disappearance of essential species from local ecosystems will cause cascading effects.
 Michael Kinnaman/Getty Images

2017 study looked at all animal populations across the planet (not just insects) by examining 27,600 vertebrate species — about half of the overall total that we know exist. They found that more than 30% of them are in decline.

Some species are facing total collapse, while certain local populations of others are going extinct in specific areas. That’s still cause for alarm, since the study authors said these localized population extinctions are a “prelude to species extinctions.”

So even declines in animal populations that aren’t yet categorized as endangered is a worrisome sign.

More than 26,500 of the world’s species are threatened with extinction, and that number is expected to keep going up.

More than 26,500 of the world's species are threatened with extinction, and that number is expected to keep going up.
The Amur leopard is critically endangered.
 DigitalART/Wikimedia Commons

According to the International Union for Conservation of Nature Red List, more than 27% of all assessed species on the planet are threatened with extinction. Currently, 40% of the planet’s amphibians, 25% of its mammals, and 33% of its coral reefs are threatened.

The IUCN predicts that 99.9% of critically endangered species and 67% of endangered species will be lost within the next 100 years.

A 2015 study that examined bird, reptile, amphibian, and mammal species concluded that the average rate of extinction over the last century is up to 100 times as high as normal.

A 2015 study that examined bird, reptile, amphibian, and mammal species concluded that the average rate of extinction over the last century is up to 100 times as high as normal.
The monarch butterfly population, like that of other insects, fluctuates widely. But scientists say the recoveries after each big dip tend to be smaller, suggesting an overall declining trend.
 Marco Ugarte/Associated Press

Elizabeth Kolbert, author of the book “The Sixth Extinction,” told National Geographic that the outlook from that study is dire; it means 75% of animal species could be extinct within a few human lifetimes.

In roughly 50 years, 1,700 species of amphibians, birds, and mammals will face a higher risk of extinction because their natural habitats are shrinking.

In roughly 50 years, 1,700 species of amphibians, birds, and mammals will face a higher risk of extinction because their natural habitats are shrinking.
Human activities like agriculture, settlements, and infrastructure development result in the loss of black rhino habitats. Black rhinos are critically endangered.
 Phil Noble/Reuters

By 2070, 1,700 species will lose 30% to 50% of their present habitat ranges thanks to human land use, a 2019 study found. Specifically, 886 species of amphibians, 436 species of birds, and 376 species of mammals will be affected and consequently will be at more risk of extinction.

Logging and deforestation of the Amazon rainforest is of particular concern.

Logging and deforestation of the Amazon rainforest is of particular concern.
An aerial view of a tract of Amazon jungle recently cleared by loggers and farmers near the city of Novo Progresso, Brazil.
 Nacho Doce/Reuters

Roughly 17% of the Amazon has been destroyed in the past five decades, mostly because humans have cut down vegetation to open land for cattle ranching, according to the World Wildlife Fund. Some 80% of the world’s species can be found in tropical rainforests like the Amazon, including the critically endangered Amur leopard. Even deforestation in a small area can cause an animal to go extinct, since some species live only in small, isolated areas.

Every year, more than 18 million acres of forest disappear worldwide. That’s about 27 soccer fields’ worth every minute.

In addition to putting animals at risk, deforestation eliminates tree cover that helps absorb atmospheric carbon dioxide. Trees trap that gas, which contributes to global warming, so fewer trees means more CO2 in the atmosphere, which leads the planet to heat up.

In the next 50 years, humans will drive so many mammal species to extinction that Earth’s evolutionary diversity won’t recover for some 3 million years, one study said.

In the next 50 years, humans will drive so many mammal species to extinction that Earth's evolutionary diversity won't recover for some 3 million years, one study said.
African elephants like this one are frequent victims of poaching and are vulnerable to extinction.
 Kenny Katombe/Reuters

The scientists behind that study, which was published in 2018, concluded that after that loss, our planet will need between 3 million and 5 million years in a best-case scenario to get back to the level of biodiversity we have on Earth today.

Returning the planet’s biodiversity to the state it was in before modern humans evolved would take even longer — up to 7 million years.

Alien species are a major driver of species extinction.

Alien species are a major driver of species extinction.
Zebra mussel shells pile up on a beach in Sleeping Bear Dunes National Lakeshore, Michigan. The zebra mussel is an invasive alien species in the Great Lakes.
Corfoto/Getty Images

study published earlier this month found that alien species are a primary driver of recent animal and plant extinctions. An alien species is the term for any kind of animal, plant, fungus, or bacteria that isn’t native to an ecosystem. Some can be invasive, meaning they cause harm to the environment to which they’re introduced.

Many invasive alien species have been unintentionally spread by humans. People can carry alien species with them from one continent, country, or region to another when they travel. Shipments of goods and cargo between places can also contribute to a species’ spread.

Zebra mussels and brown marmorated stink bugs are two examples of invasive species in the US.

The recent study showed that since the year 1500, there have been 953 global extinctions. Roughly one-third of those were at least partially because of the introduction of alien species.

Oceans are absorbing a lot of the excess heat trapped on Earth because of greenhouse gases in the atmosphere. That kills marine species and coral reefs.

Oceans are absorbing a lot of the excess heat trapped on Earth because of greenhouse gases in the atmosphere. That kills marine species and coral reefs.
A bleached coral reef near Guam in the Pacific Ocean. A 2018 study found that severe bleaching outbreaks now hit reefs four times more often they did a few decades ago.
David Burdick/NOAA/AP

The planet’s oceans absorb a whopping 93% of the extra heat that greenhouse gases trap in Earth’s atmosphere. Last year was the oceans’ warmest year on record, and scientists recently realized that oceans are heating up 40% faster than they’d previously thought.

Higher ocean temperatures and acidification of the water cause corals to expel the algae living in their tissues and turn white, a process known as coral bleaching.

As a consequence, coral reefs — and the marine ecosystems they support — are dying. Around the world, about 50% of the world’s reefs have died over the past 30 years.

Species that live in fresh water are impacted by a warming planet, too.

Species that live in fresh water are impacted by a warming planet, too.
The Goose Lake redband trout is endemic to tributaries in northeastern California and southeastern Oregon.
 Steve Howard/Getty Images

A 2013 study showed that 82% of native freshwater fish species in California were vulnerable to extinction because of climate change.

Most native fish populations are expected decline, and some will likely be driven to extinction, the study authors said. Fish species that need water colder than 70 degrees Fahrenheit to thrive are especially at risk.

Warming oceans also lead to sea-level rise. Rising waters are already impacting vulnerable species’ habitats.

Warming oceans also lead to sea-level rise. Rising waters are already impacting vulnerable species' habitats.
The Bramble Cay melomys is the first species to go extinct because of human-driven climate change.
 nmulconray/Getty Images

Water, like most things, expands when it heats up — so warmer water takes up more space. Already, the present-day global sea level is 5 to 8 inches higher on average than it was in 1900, according to Smithsonian.

In February, Australia’s environment minister officially declared a rodent called the Bramble Cay melomys to be the first species to go extinct because of human-driven climate change — specifically, sea-level rise.

The tiny rat relative was native to an island in the Queensland province, but its low-lying territory sat just 10 feet above sea level. The island was increasingly inundated by ocean water during high tides and storms, and those salt-water floods took a toll on the island’s plant life.

That flora provided the melomys with food and shelter, so the decrease in plants likely led to the animal’s demise.

Warming oceans are also leading to unprecedented Arctic and Antarctic ice melt, which further contributes to sea-level rise. In the US, 17% of all threatened and endangered species are at risk because of rising seas.

Warming oceans are also leading to unprecedented Arctic and Antarctic ice melt, which further contributes to sea-level rise. In the US, 17% of all threatened and endangered species are at risk because of rising seas.
Two Adélie penguins standing atop a block of melting ice in east Antarctica.
Pauline Askin/Reuters

Melting ice sheets could raise sea levels significantly. The Antarctic ice sheet is melting nearly six times as fast as it did in the 1980s. Greenland’s ice is melting four times faster now than it was 16 years ago. It lost more than 400 billion tons of ice in 2012 alone.

In a worst-case scenario, called a “pulse,” warmer waters could cause the glaciers that hold back Antarctica’s and Greenland’s ice sheets to collapse. That would send massive quantities of ice into the oceans, potentially leading to rapid sea-level rise around the world.

Sea-level rise because of climate change threatens 233 federally protected animal and plant species in 23 coastal states across the US, according to a report from the Center for Biological Diversity.

The report noted that 17% of all the US’s threatened and endangered species are vulnerable to rising sea levels and storm surges, including the Hawaiian monk seal and the loggerhead sea turtle.

If “business as usual” continues regarding climate change, one in six species is on track to go extinct.

Bornean orangutans are one of the world’s top 10 endangered species.
Tim Chong/Reuters

An analysis published in 2015 looked at over 130 studies about declining animal populations and found that one in six species could disappear as the planet continues warming.

Flora and fauna from South America and Oceania are expected top be the hardest hit by climate change, while North American species would have the lowest risk.

Previous mass extinctions came with warning signs. Those indicators were very similar to what we’re seeing now.

Previous mass extinctions came with warning signs. Those indicators were very similar to what we're seeing now.
If global warming continues, subtropical stratocumulus clouds could disappear, which would raise planet-wide temperatures by 8 degrees Celsius.
Aleksandar Georgiev/Getty Images

The most devastating mass extinction in planetary history is called the Permian-Triassic extinction, or the “Great Dying.” It happened 252 million years ago, prior to the dawn of the dinosaurs.

During the Great Dying, roughly 90% of the Earth’s species were wiped out; less than 5% of marine species survived, and only a third of land animal species made it, according to National Geographic. The event far eclipsed the cataclysm that killed the last of the dinosaurs some 187 million years later.

But the Great Dying didn’t come out of left field.

Scientists think the mass extinction was caused by a l arge-scale and rapid release of greenhouse gases into the atmosphere by Siberian volcanoes, which quickly warmed the planet — so there were warning signs. In fact, a 2018 study noted that those early signs appeared as much as 700,000 years ahead of the extinction.

“There is much evidence of severe global warming, ocean acidification, and a lack of oxygen,” the study’s lead author, Wolfgang Kießling, said in a release.

Today’s changes are similar but less severe — so far.

There’s still some debate about whether we’re truly in the middle of a sixth extinction. But there is agreement that the extinctions we’re seeing now are our fault.

There's still some debate about whether we're truly in the middle of a sixth extinction. But there is agreement that the extinctions we're seeing now are our fault.
Agent Alex Lacerda of Brazil’s Institute of Environment and Renewable Natural Resources carries a sample of wood that was confiscated at an illegal sawmill.
Ricardo Moraes/Reuters

Scientists are still arguing about whether the Earth is truly in the midst of another mass extinction. Smithsonian paleontologist Doug Erwin, an expert on the Great Dying, says we’re not there yet, according to The Atlantic.

But that debate may be missing the “forest for the trees.” As Kolbert told National Geographic, “by the time we have definitive answers to that question, it’s possible three-quarters of all species on Earth could be gone.”

Already, there is consensus on one aspect of the extinction trend: Homo sapiens are to blame.

According to a 2014 study, current extinction rates are 1,000 times higher than they would be if humans weren’t around.

“There are very few, if any, extinctions that we know about in the last 100 years that would have taken place without human activity,” Kolbert said.

Our Planet Is So Fucked That Some Women Are Choosing to Not Have Kids

“It sounds dramatic, but I’m just being realistic. The way we live currently simply cannot sustain more people.”

Image by Callie Beusman

Climate change is realanthropogenic, and only getting worse. In September, atmospheric carbon levels reached an irreversible tipping point, one that scientists have been warning us about for years.

Despite this extremely worrying fact, president-elect Donald Trump—who once tweeted, “the concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive”—recently announced that he had picked Myron Ebell, an active climate change denier, to lead the transition of the Environmental Protection Agency.

Read moreReuse, Reduce, Reproductive Rights: How Abortion Can Help Save the Planet

This bodes poorly for us, and even worse for our potential offspring: Research shows that future generations will be the ones to suffer the worst consequences of climate change, not us. In light of this fact, some women are starting to rethink the idea of having children.

Harriet Spark, a social media coordinator and dive instructor living in Sydney, Australia, is one of them. “I work in environmental advocacy, so every day I’m reading and learning about the myriad of issues our world faces,” Spark toldBroadly. While at work, Spark encounters head-on the disastrous and already-evident consequences of climate change, such as the mass coral bleaching of the Great Barrier Reef.

Spark’s reasoning for abstaining from having children is two-fold: She does not want to contribute to pre-existing resource depletion by adding another human to this planet, and she does not want to bring a child into a world she sees as doomed. “It sounds dramatic, but I’m just being realistic,” said Spark. “The way we live currently simply cannot sustain more people.”

Stefanie Weiss, a writer in her mid-40s based in New York City, also decided to be child-free out of concern for the environment.”Years ago, there was a study I learned about,” Weiss told Broadly, referencing a 2008 study from a pair of researchers at Oregon State University. “There’s this number, 9,441. That’s the amount of additional metric tons of carbon you add to the atmosphere for every child you have. You can never take it back. That stopped me in my tracks.”


There’s this number, 9,441. That’s the amount of additional metric tons of carbon you add to the atmosphere for every child you have.

That same study put those 9,441 metric tons of carbon dioxide into perspective: If a typical American decided to recycle newspapers, magazines, glass, plastic, aluminum, and steel cans over the course of her entire life, she would save the environment from just 17 metric tons of carbon emissions.

While the concept of holding off on childbirth because of the dismal state of the world certainly isn’t new, groups like Conceivable Future are. The nonprofit seeks to bring “awareness to the threat climate change poses to reproductive justice.” “Our integrating question is, how does climate change affect people’s reproductive choices?” said Conceivable Future co-founder Meghan Kallman. “This is a question that has resonated with huge numbers of people.”

Through local groups and nationwide advocacy, the organization hopes to open up the discussion for women everywhere. “We give everyone space to explore this really personal and also deeply political decision as it relates to their own lives,” said Kallman.

Conceivable Future’s community-led events have been hosted at old mills and movie theaters but are more likely to be in someone’s living room, Kallman said. The women’s perspectives are often just as diverse as the venues. “We have some people who are really convinced they are not having children, some who have made a commitment to have children, and then we have people who are undecided,” said Kallman. “Sometimes there are even a lot of kids [brought by moms] at the meeting.”


Young women are way more likely to take this seriously and to see the message as empowering.

Their advocacy does not stop solely at the question of what climate change means to women’s reproductive futures. “The people that we organize with go on to do all kinds of things, things that change [political] systems,” said Kallman.

The organization currently touts 68 “testimonies,” documents in writing or video that give human voice to grappling with reproduction in light of climate change. “The idea of testimony is that your truth and these lived experiences have more ability to move political structures than all the charts and numbers in the world,” said Kallman.

Deciding whether to have children is not an easy process for women, Kallman and others say. Still, they may be more receptive to the argument that abstaining from reproduction is the best choice from the environment. “I have seen a very gendered response,” said Travis Rieder, a research scholar at the Johns Hopkins Berman Institute of Bioethics and author of Toward a Small Family Ethic: How Overpopulation and Climate Change Are Affecting the Morality of Procreation.

“Young women are way more likely to take this seriously and to see the message as empowering,” he continued. “I’ve taught at Georgetown and I teach at Hopkins, and these are very ambitious young folks, and I imagine that a lot of these women already saw family planning as a challenge to their careers.”


For More Stories Like This, Sign Up for Our Newsletter

Young men, he added, are far less likely to consider abstaining from having children. “In all my years of teaching this, the number of men who have been quickly converted I could count on one hand,” said Rieder. “They are very vocal opponents.” To Rieder, it makes sense that men would be less likely to carefully consider the impact of their reproductive choices: “I imagine that a lot of men have either consciously or unconsciously assumed that they were always going to be able to have their family because someone else was doing so much of the labor,” he explained.

That male arrogance rings true with Weiss, the New York City-based writer in her mid-40s. “It was mostly men, in my personal life and online, that told me I was selfish for making this decision,” she said. “I was in a serious relationship with a boyfriend at the time when I made the decision [not to have children]. We weren’t even at the stage where we were thinking about having kids, but he still argued with me about it. He thought that ethically I was wrong, that I was selfish.”

Weiss sees herself as someone making a pragmatic, moral decision—the world cannot support more life, so she will not bring more life into the world. The irony of her ex-boyfriend calling her “selfish” is not lost on her. “It’s because men don’t even have to contemplate the decisions that women have to make, about their careers, about their bodies,” she said.

Humans cause climate change. Do we just need fewer humans?

Grist / GoodLifeStudio / Getty Images

Q. How come the huge impact of our population growth on climate change doesn’t get more attention when we talk about how to take action against warming?

— Too Many Humans, Too Little Time


There’s long been a contingent of environmentalists who love to point to the world’s population as a major factor in humans’ self-destruction. The logic seems basic: Climate change is caused by humans, so fewer humans should limit the harm of climate change.

The “optimal” global population to sustain ecosystems is considered to be between 1 and 2 billion. The actual population at present is a bit more than 7.5 billion.

The issue of how you arrive at fewer humans is decidedly less basic. Some entity has to dictate which humans get to produce more humans — or in an even more macabre scenario, which humans stay and which humans go. The way that societies have made that decision, historically, is by ranking the worth of different groups — usually by ethnicity, often by sexuality, frequently by mental and physical ability — and sterilizing those deemed to be of lower value. In the U.S. alone, LatinosNative AmericansAfrican-Americans, and the mentally ill and disabled have all been victims of this dehumanizing practice, shockingly all as recently as the 1970s.

“A main argument for why those coerced sterilizations were done was to alleviate the pressure that population growth was putting on state resources, because these groups were disproportionately receiving welfare,” Jade Sasser, a professor of feminist political ecology at the University of California, Riverside, and author of On Infertile Ground: Population Control and Women’s Rights in the Era of Climate Change, told me.

That argument goes directly back to the English economist Thomas Malthus, who wrote in the late-18th century that unchecked population growth would bring with it food shortages, illness, and conflict, she explained. “And it actually exacerbates inequality because it suggests that the poor and people of color are responsible for the inequalities that actually constrain their lives and their choices.”

The man who many count as responsible for bringing Malthusian logic into mainstream environmental theory is Stanford University conservation biologist Paul Ehrlich, co-author of the controversial book “The Population Bomb.” (His wife, Anne, is his frequent collaborator and an uncredited co-author on that seminal work.) I called him to try to answer how much we can blame overpopulation for climate change.

Fifty years after his book’s release, Ehrlich still believes that population is an under-recognized threat in environmental degradation because it naturally drives up consumption. In collaboration with John Holdren, who went on to serve as President Barack Obama’s senior science and technology advisor, Ehrlich developed the “IPAT equation” in the 1970s:

Environmental impact (I) = population (P) x affluence or, essentially, propensity to consume (A) x technology (T).

Looking at the equation, it stands to reason that if we are able to greatly reduce consumption and greatly improve the efficiency of our technology, wouldn’t that allow us to potentially forgo population control?

“It certainly would carry less weight,” Ehrlich said. “But the problem is that the three together now are on a doomsday path. I don’t see the slightest chance of us changing to avoid what’s coming. The idea that you can just ignore how many people there are and get a technological fix to worry about food or climate or war or so on — it’s as illogical as religion.”

It likely comes as no surprise that in the half-century since IPAT’s development a new generation of academics has made modifications to it. I found one in a lecture from an industrial ecology course taught at Dartmouth College.

This alternate version replaces affluence with per capita Gross Domestic Product, the value of all goods and services in a particular economy divided by its total population. The equation reads:

Environmental impact = GDP per capita x population x technology.

Population cancels out, of course, and you end up with:

Environmental impact = GDP x technology.

This modified IPAT can be used to show how different countries contribute to climate change through their energy use — there are wealthy countries with relatively clean technology (like Denmark, where wind energy is dominant), middle-income countries with high-polluting technology (like coal-dependent India), and low-income countries who consume very little but also have regressive technology (like Somalia, which relies heavily on diesel generators).

In our conversation, Ehrlich suggests we should aspire to have a system where everyone consumes the same amount. At the same time, he says, we should work toward making that consumption as sustainable as possible. But, he adds, “I see no way you can solve problems of equity without the rich giving up a lot of what they do to make room for the poor to do better.”

Without rapid development of clean-powered circular economies and a massive transfer of wealth, we end up back with population being an active factor in climate change.

OK, so how do you choose which people have to go? Imagine the United States Congress — largely white people, many of whom enjoy great wealth, but generally all of whom consume plenty (in some cases thanks to their support of dirty technologies). If those people are making the rules on population control in the U.S., do you think they’re going to advocate for the rights of communities that aren’t like most of its members?

In fact, the one point that both the reproductive justice community and neo-Malthusians can agree on is that the provision of voluntary, universal access to birth control is a bare-minimum human right. In the United States, one of the highest-emitting countries in the world, it’s misleading to discuss population-based policies — such as China’s one-child policy — as a reasonable solution to climate change when access to reproductive healthcare and any number of should-be basic resources here is so uneven.

“There are those environmentalists who are saying it’s not about voluntary access to birth control, it’s about creating demand and convincing people to have fewer children,” said Sasser, the UC Riverside professor. “I find that argument frustrating because the poor tend to use far fewer polluting resources than the wealthy, and until we really get to a place in which those kinds of social inequalities are eliminated, I don’t think we should be targeting the poor for lowering their resource consumption. It’s based on a blindness to inequalities that exist throughout the world.”

So my answer to your question, TMHTLT, is this: Talking about population as the primary cause of climate change is like talking about food as the primary cause of obesity. You can’t have obesity without food. (I mean, you can’t survive long enough to be obese without food.) But it’s not always the primary cause of obesity. There’s also systemic lack of access to healthy food, poor quality healthcare, genetic illness, and even environmental factors.

Simply limiting food without addressing any of the other factors doesn’t guarantee an improvement in the overall health of the person who is obese. Similarly, narrowly focusing on population without making incredible efforts to reduce our consumption and improve our technology is irresponsible.