Half of Earth's species could go extinct by 2050 unless humanity addresses man-made climate change, according to biologists.

There have been five mass extinctions in the history of planet Earth. The most recent occurred 65 million years ago, when the dinosaurs famously bit the dust. Now, studies suggest human beings are currently causing a sixth.

In June 2015, the journal, Science Advances, examined the rate at which species were going extinct. It found that the rate of mammal and vertebrate species loss was up to 100 times higher than past rates, indicating that a sixth mass extinction is already underway.

Science Advances is far from the only study that presents evidence humans are the reason behind the next mass extinction.

A group of scientists specializing in trying to prevent that from happening are gathering in the Vatican this week at the behest of Pope Francis for the conference entitled, “How to Save the Natural World on Which We Depend.”

The conference will include a workshop on biological extinction, featuring speakers like Nobel laureate and President of the Pontifical Academy of Science, Werner Arber; Cambridge professors Sir Partha Dasgupta and Lord Martin Rees; and University of Chicago professor Neil Shubin, to name a few.

The conference aims to highlight biological extinction in a global context and to identify root causes, including hunting, clearing land for agriculture and urban dvelopment, the introduction of alien spieces like weeds and pests and pathogens, and climate change.  

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Pope Francis’ previous efforts to promote sustainability and combat climate change include publishing a letter in June 2015 which called for sweeping changes in consumerism and for supporting the world’s poorest people, who are most affected by climate change. He has also urged the United Nations to “take a very strong stand” against climate change at the Paris Climate Accords. Parties committed to the international agreement aim to limit global warming to 1.5 degrees Celsius during the next century. 

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At the same time the journal was published, Paul Ehrlich, Professor of Population Studies and Biology at Stanford University, published a video with a similar warning.

“We are now moving into another one of these [extinction] events that could easily ruin the lives of everybody on the planet because we’re utterly dependent on other organisms for our food, for our climate, for all sorts of things,” said Ehrlich. “When you look at a conservative estimate of how fast mammals are going extinct today, it runs somewhere between fifteen and a hundred times as fast.”

Ehrlich will be speaking at the Vatican Conference.

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Even if species do not completely die out, changes in global climate can have devastating effects on ecosystems. For example, climate is changing at a faster rate than species are able to adapt, according to evolutionary biologist, John Wiens.

“In almost half the species looked at, there have been local extinctions already,” Wiens said in a study last December. “Species cannot change fast enough to keep up with a small change in climate. That’s the big implication – even a small change in temperature and they cannot handle it.”

The study demonstrates the fragility of ecosystems and how even extremely minor increases in global temperatures can cause irreparable damage to life on Earth.  

Ehrlich provides another example as to the ripple effect from losing even a portion of a species’ population: “We are not likely to lose the honeybee as a species but we’re already losing it in lots of places where it’s very important, say for pollinating your almond orchards.”

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Bees pollinate roughly a third of the food humans eat as well as fruits, vegetables, and plants that countless other mammals rely on for food. They are absolutely vital in maintaining ecosystems. Even if bees survive as a species, dwindling numbers could lead to a disastrous domino effect – and that’s just one example. Scientists estimate there could be as many as one trillion species on Earth, all of which exist interdependently in a delicate balance.   

Ninety-nine percent of species that have ever lived on planet Earth have gone extinct. There is hope, however. According to Science Advances, it’s not too late to curb mass extinctions, and reestablish an ecological balance. But we have to act now.

“Averting a dramatic decay of biodiversity and the subsequent loss of ecosystem services is still possible through intensified conservation efforts,” the report says, “but that window of opportunity is rapidly closing.”


Defend the Planet

Half of the Species on Earth Could Go Extinct by 2050: Scientists

By James O'Hare