Human impacts on the environment are putting our future at risk, they say.
A large crowd of people at a concert in Paris. Image: James Cridland/Flickr
More than 15,000 scientists from 184 countries warn the evidence is clear: Current and future human health and wellbeing are at serious risk from climate change, deforestation, loss of access to freshwater, species extinctions, and human population growth.
Eminent scientists Jane Goodall, E.O. Wilson, and James Hansen are among those who have cosigned the warning, published Monday in the journal BioScience. The article, titled “World Scientists' Warning to Humanity: A Second Notice,” has 15,372 signatories in total, from a range of scientific disciplines. It is thought to be the largest-ever formal support by scientists for a journal article.
The “Second Notice” article updates the original “World Scientists' Warning to Humanity” document released in 1992, 25 years ago this month. Signed by 1700 scientists, including most of the living Nobel Prize science winners, it warned that human impacts on the environment were putting “at serious risk the future that we wish for human society” and detailed several worrisome trends.
“We did the update because we wanted to let the public know where we stand today,” said William Ripple, an ecologist at Oregon State University and co-author the “Second Notice” article. With few exceptions, those trends have gotten far worse over the past 25 years.
“Since 1992, CO2 [carbon dioxide] emissions have jumped 62 percent and the global temperature is up 29 percent, while the abundance of vertebrate wildlife has plunged 29 percent,” Ripple told Motherboard.
The data compiled by the researchers revealed that in the past 25 years, there has been:
- A 26 percent reduction in the amount of freshwater available per capita
- A 75 percent increase in the number of ocean dead zones
- A loss of nearly 300 million acres of forestland
“These are alarming trends. We need the services provided by nature for our own survival,” he said.
The plant, animal, insect, fish, and other species in nature perform a variety of tasks, like producing oxygen, cleaning water, and pollination. Altogether the goods and services nature provides is estimated to be worth between $125-145 trillion USD per year. And with addition of two billion people since 1992—a 35 percent increase in global population—those vital services are under increasing stress, the article said.
One positive trend is the healing of the ozone layer, which protects all living things from harmful ultraviolet radiation. In 1987, countries came together under the UN’s Montreal Protocol to ban ozone-damaging chemicals. The growing use of renewable energy is another positive trend, said Ripple.
There was little focus on climate change in the original warning, but it did urge humanity to move away from using fossil fuels. At the UN climate conference in Bonn, Germany on Monday, another group of scientists warned that global CO2 emissions are likely to rise after being stable for the past three years.
“Climate change is here. It is dangerous. And it is about to get much worse,” said Johan Rockström, executive director of the Stockholm Resilience Centre, an international centre for sustainability science, in a statement.
US CO2 emissions are expected to rise 2.2 percent in 2018 mostly because of a cold winter forecast. Emissions from China and India are also still growing, albeit at a slower pace than a few years ago.
“The news that emissions are rising after the three-year hiatus is a giant leap backwards for humankind,” said Amy Luers, executive director of Future Earth, an international sustainability science research organization.
“Emissions need to peak soon and approach zero by 2050,” Luers said in a release.
Ripple agrees that there is an urgent need to reduce CO2 emissions, and said their “Second Notice” article lists a number of ways to halt the environmental trend declines, including creating more parks and nature reserves, curbing wildlife trade, shifting to plant-based diets, expanding family planning and educational programs for women, and massively adopting renewable energy and other "green" technologies.
“Working together... we can make great progress for the sake of humanity and the planet on which we depend,” the article concludes optimistically.
“We are hoping that our paper will ignite a widespread public debate about the global environment and climate,” said Ripple.
However, the media ignored the original 1992 Scientists’ Warning to Humanity, with The New York Times and Washington Post saying it wasn’t newsworthy.
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