Bill Ripple, a distinguished professor of ecology at Oregon State University, has spent a large part of his career studying the interplay between predators, prey and plant life in and around Yellowstone National Park.
While his work has earned him a solid reputation in academic circles, he was hardly a household name.
But that changed in December, when he took the lead role in authoring a paper titled “World Scientists’ Warning to Humanity: A Second Notice,” which was published in the journal BioScience.
Written with seven co-authors, the paper was an update of a headline-grabbing document published 25 years earlier by the Union of Concerned Scientists. When it came out in 1992, the original “Warning” was signed by more than 1,700 scientists and created a stir with its dire predictions of environmental disaster for the planet.
Ripple’s paper was signed by more than 15,000 scientists from 184 countries prior to publication and has since been signed by about 5,000 more, calling renewed attention to the environmental emergency confronting the world and casting him in the unfamiliar role of public figure.
“I normally don’t write letters to humanity,” Ripple told an audience of more than 100 people at Tuesday’s meeting of the City Club of Corvallis. “I work as an ecologist.”
Last year, as he was becoming increasingly concerned about the accelerating pace of climate change and increases in extreme weather events, he came across a copy of the earlier paper. Reading it, he realized things had generally gotten worse since the “World Scientists’ Warning to Humanity” and decided it was time for an update.
“That’s when the light bulb went off in my head,” he said.
Ripple and his co-authors looked at a number of measures of global environmental health to see how it had changed since 1992. While the ozone layer has bounced back nicely following sharp reductions in chlorofluorocarbons, other metrics have gotten far worse: per capita water resources are down 26 percent, forest cover is down 2.8 percent, vertebrate wildlife abundance is down 29 percent, ocean dead zones are up 75 percent and carbon dioxide emissions are up 62 percent, leading to a corresponding increase in average temperatures.
What’s driving these problems? Perhaps the biggest factor, Ripple suggested, is human population growth, which is up by 35 percent — roughly 2 billion souls — in the last 25 years.
“A Second Notice” clearly struck a chord with both the scientific community and the public.
According to Ripple, the paper has been covered by more than 300 news outlets, including CNN, The Washington Post and The Boston Globe. It’s been tweeted more than 8,000 times and has generated a Twitter following of 14 million users. Altmetric, a service that rates scientific papers by the number of mentions they get in mass media and digital platforms, currently ranks it No. 6 out of more than 8.9 million publications.
Ripple and his co-authors have formed an organization called the Alliance of World Scientists to do follow-up work on issues raised by the paper, which has attracted more than 12,000 members.
Despite all that attention, however, Ripple worries that people — and especially national governments — still aren’t taking the global environmental crisis seriously enough.
At Tuesday’s presentation, he played two video clips to illustrate the problem.
The first was a 1992 talk by Severn Suzuki, the daughter of Canadian environmentalist David Suzuki. At the age of 12, she addressed the United Nations Earth Summit in Rio de Janeiro, urging the delegates to protect the world from environmental harm for the sake of future generations.
The second clip showed Sophie Kivlehan, the 18-year-old granddaughter of NASA climate scientist James Hansen, speaking on the sidelines of last year’s U.N. climate talks. Referencing Suziki’s speech from 25 years earlier, Kivlehan charged that little had changed since then.
“I am afraid and I am angry at the problems that greedy and selfish adults have caused,” she said. “Adults, you say you love us, but I challenge you to make your actions reflect your words.”
If the governments of the world don’t take concerted action to halt climate change, overconsumption of natural resources and other global threats soon, Ripple concluded, it could be too late.
“Now,” he said, “I ask: Are we going to be changing in time?”