Earth's Climate After 2030: Conditions Could Resemble Era 3 Million Years Ago, Scientists Predict
By Tim Radford
Humankind, in two centuries, has transformed the climate. It has reversed a 50-million-year cooling trend.
Scientists conclude that the profligate combustion of fossil fuels could within three decades take planet Earth back to conditions that existed in the Pliocene three million years ago, an era almost ice-free and at least 1.8°C and possibly 3.6°C warmer than today.
But there is a much earlier warming precedent. The Eocene planet at its warmest 50 million years ago was perhaps 13°C warmer than it has been for almost all human history.
Its continents were differently configured, the Arctic was characterized by swampy forests that might have looked a little like the Louisiana bayous of the U.S., and the first mammals had begun to colonize the globe.
And then, steadily but unevenly, the globe began to cool towards a level comfortable for human evolution, and then much later to a level that permitted the birth of agriculture and the foundation of a civilization that fostered writing, music, poetry, scholarship and scientific skills capable of tracing the detailed history of the last 50 million years and at the same time projecting a changing future.
"We can use the past as a yardstick to understand the future, which is so different from anything we have experienced in our lifetime," said John Williams, a palaeo-ecologist at the University of Wisconsin-Madison.
"People have a hard time projecting what the world will be like in five or 10 years from now. This is a tool for predicting that—how we head down those paths, and using deep geologic analogues to think about changes in time."
Dr. Williams and his colleagues report in the Proceedings of the National Academy of Sciences that they compared the climate computer forecasts for the mean summer and winter world temperatures from 2020 to 2280, with historic and prehistoric warm periods over the last 50 million years.
And they identified a hotspot in the mid-Pliocene more than 3 million years ago as the best match for global climates after 2030.
They reason that if nations fulfill the promise made in Paris in 2015 to reduce greenhouse gas emissions and keep average global warming to no more than 1.5°C above the levels for most of human history, then that is what global conditions will be like.
If, on the other hand, nations go on burning fossil fuels under the business-as-usual scenario, then by 2150 the world will be very like the early Eocene, 50 million years ago.
And if that is the case, at least 9 percent of the globe—including northern Australia, east and south-east Asia, and the coastal Americas—will experience what the scientists call "geologically novel climates": that is, conditions for which the past can offer no match at all.
It is a tenet of geology that the present is key to the past. If so, the past can also illuminate the future: what has happened before can happen again.
In the course of decades of careful study, climate scientists have identified examples of mass extinction and catastrophic climate change from the Cretaceous and the Permian and even the late Carboniferous, when so much carbon dioxide was taken from the atmosphere and buried as fossil plant material that the planet almost became a snowball.
Human Flourishing Ended
So cogent have been the warnings from the distant past that researchers argue that the epoch in which modern humans flourished—geologists call it the Holocene—effectively came to an end midway through the 20th century.
What initially provided a safe operating space for emerging humanity will, they think, become known as the Anthropocene, because human activity has now so dramatically changed the climate, the landscape and the conditions under which other lifeforms flourish.
"The further we move from the Holocene, the greater we move out of safe operating space," professor Williams said.
"In the roughly 20 to 25 years I have been working in the field, we have gone from expecting climate change to happen, to detecting its effects, and now we are seeing it is causing harm.
Reposted with permission from our media associate Climate News Network.
Britain's Prince William interviewed famed broadcaster David Attenborough on Tuesday at the World Economic Forum's annual meeting in Switzerland.
During the sit-down, the 92-year-old naturalist advised the world leaders and business elite gathered in Davos this week that we must respect and protect the natural world, adding that the future of its survival—as well as humanity's survival—is in our hands.
What's more, the accounting firm predicts that another 21 million electric cars will be on the road globally over the next decade due to growing market demand for clean transportation, government subsidies, as well as bans on fossil fuel cars.
By Matthew Savoca
Plastic pollution in the world's oceans has become a global environmental crisis. Many people have seen images that seem to capture it, such as beaches carpeted with plastic trash or a seahorse gripping a cotton swab with its tail.
Greenland is melting about four times faster than it was in 2003, a new study published Monday in the Proceedings of the National Academy of Sciences found, a discovery with frightening implications for the pace and extent of future sea level rise.
"We're going to see faster and faster sea level rise for the foreseeable future," study lead author and Ohio State University geodynamics professor Dr. Michael Bevis said in a press release. "Once you hit that tipping point, the only question is: How severe does it get?"
Finally, some good news about the otherwise terrible partial government shutdown. A federal judge ruled that the Trump administration cannot issue permits to conduct seismic testing during the government impasse.
The Justice Department sought to delay—or stay—a motion filed by a range of coastal cities, businesses and conservation organizations that are suing the Trump administration over offshore oil drilling, Reuters reported. The department argued that it did not have the resources it needed to work on the case due to the shutdown.
Most people have heard of the Amazon, South America's famed rainforest and hub of biological diversity. Less well known, though no less critical, is the Pantanal, the world's largest tropical wetland.
Like the Amazon, the Pantanal is ecologically important and imperiled. Located primarily in Brazil, it also stretches into neighboring Bolivia and Paraguay. Covering an area larger than England at more than 70,000 square miles, the massive wetland provides irreplaceable ecosystem services that include the regulation of floodwaters, nutrient renewal, river flow for navigability, groundwater recharge and carbon sequestration. The wetland also supports the economies of the four South American states it covers.
By Andrea Germanos
Organizers said 35,000 people marched through the streets of the German capital on Saturday to say they're "fed up" with industrial agriculture and call for a transformation to a system that instead supports the welfare of the environment, animals and rural farmers.
By Patrick Rogers
If you have ever considered making the switch to an environmentally friendly electric vehicle, don't drag your feet. Though EV prices are falling, and states are unveiling more and more public charging stations and plug-in-ready parking spots, the federal government is doing everything it can to slam the brakes on our progress away from gas-burning internal combustion engines. President Trump, likely pressured by his allies in the fossil fuel industry, has threatened to end the federal tax credits that have already helped put hundreds of thousands of EVs on the road—a move bound to harm not only our environment but our economy, too. After all, the manufacturing and sale of EVs, hybrids, and plug-in hybrids supported 197,000 jobs in 2017, according to the most recent U.S. Energy and Employment Report.