Earth's ecosystems nearing catastrophic 'tipping point,' warn scientists

Our planet is heading toward a sudden breakdown, a group of international scientists warn, unless humans adopt more sustainable practices. 

NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring
This composite image uses a number of swaths of the Earth's surface taken in January 2012.

Earth is rapidly headed toward a catastrophic breakdown if humans don't get their act together, according to an international group of scientists.

Writing Wednesday (June 6) in the journal Nature, the researchers warn that the world is headed toward a tipping point marked by extinctions and unpredictable changes on a scale not seen since the glaciers retreated 12,000 years ago.

"There is a very high possibility that by the end of the century, the Earth is going to be a very different place," study researcher Anthony Barnosky told LiveScience. Barnosky, a professor of integrative biology from the University of California, Berkeley, joined a group of 17 other scientists to warn that this new planet might not be a pleasant place to live.

"You can envision these state changes as a fast period of adjustment where we get pushed through the eye of the needle," Barnosky said. "As we're going through the eye of the needle, that's when we see political strife, economic strife, war and famine." [Top 10 Ways to Destroy Earth]

The danger of tipping

Barnosky and his colleagues reviewed research on climate change, ecology and Earth's tipping points that break the camel's back, so to speak. At certain thresholds, putting more pressure on the environment leads to a point of no return, Barnosky said. Suddenly, the planet responds in unpredictable ways, triggering major global transitions.

The most recent example of one of these transitions is the end of the last glacial period. Within not much more than 3,000 years, the Earth went from being 30 percent covered in ice to its present, nearly ice-free condition. Most extinctions and ecological changes (goodbye, woolly mammoths) occurred in just 1,600 years. Earth's biodiversity still has not recovered to what it was.

Today, Barnosky said, humans are causing changes even faster than the natural ones that pushed back the glaciers — and the changes are bigger. Driven by a 35 percent increase in atmospheric carbon dioxide since the start of the Industrial Revolution, global temperatures are rising faster than they did back then, Barnosky said. Likewise, humans have completely transformed 43 percent of Earth's land surface for cities and agriculture, compared with the 30 percent land surface transition that occurred at the end of the last glacial period. Meanwhile, the human population has exploded, putting ever more pressure on existing resources. [7 Billion Population Milestones]

"Every change we look at that we have accomplished in the past couple of centuries is actually more than what preceded one of these major state changes in the past," Barnosky said.

Backing away from the ledge

The results are difficult to predict, because tipping points, by their definition, take the planet into uncharted territory. Based on past transitions, Barnosky and his colleagues predict a major loss of species (during the end of the last glacial period, half of the large-bodied mammal species in the world disappeared), as well as changes in the makeup of species in various communities on the local level. Meanwhile, humans may well be knotting our own noose as we burn through Earth's resources.

"These ecological systems actually give us our life support, our crops, our fisheries, clean water," Barnosky said. As resources shift from one nation to another, political instability can easily follow.

Pulling back from the ledge will require international cooperation, Barnosky said. Under business-as-usual conditions, humankind will be using 50 percent of the land surface on the planet by 2025. It seems unavoidable that the human population will reach 9 billion by 2050, so we'll have to become more efficient to sustain ourselves, he said. That means more efficient energy use and energy production, a greater focus on renewable resources, and a need to save species and habitat today for future generations.

"My bottom line is that I want the world in 50 to 100 years to be at least as good as it is now for my children and their children, and I think most people would say the same," Barnosky said. "We're at a crossroads where if we choose to do nothing we really do face these tipping points and a less-good future for our immediate descendents."

Follow Stephanie Pappas on Twitter @sipappas or LiveScience @livescience. We're also on Facebook Google+

Copyright 2012 LiveScience, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Earth's ecosystems nearing catastrophic 'tipping point,' warn scientists
Read this article in
https://www.csmonitor.com/Science/2012/0607/Earth-s-ecosystems-nearing-catastrophic-tipping-point-warn-scientists
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe