A new report by 22 international scientists published in Thursday's edition of the journal Nature is stating we are nearing an age where we will have reached the "tipping point" on Earth that, once passed, will have "destructive consequences."
Anthony Barnosky, professor of integrative biology at the University of California, Berkeley, and lead author for the study explained in a university press release that the research presents a combination of factors that lead to this tipping point. They include population growth, destruction of ecosystems and climate change as the factors.
“It really will be a new world, biologically, at that point,” Barnosky said in a statement. “The data suggests that there will be a reduction in biodiversity and severe impacts on much of what we depend on to sustain our quality of life, including, for example, fisheries, agriculture, forest products and clean water. This could happen within just a few generations.”
The report comes just before United Nations Rio+20 Earth Summit in Rio de Janeiro later this month.
Researchers from a variety of disciplins -- biologists, ecologists, complex-systems theoreticians, geologists and paleontologists -- contributed to the report called "Approaching a State Shift in Earth's Biosphere."
Here Barnosky discusses the "tipping point" scientists believe they've seen in the past and the plans they suggest for avoiding the point of no return:
Berkley also notes co-author Elizabeth Hadly from Stanford University saying this "tipping point" is getting close in some parts of the world. It is hypothesized in the paper that once the 50 to 90 percent of the area has been changed, the effects will be irreversible:
Currently, to support a population of 7 billion people, about 43 percent of Earth’s land surface has been converted to agricultural or urban use, with roads cutting through much of the remainder. The population is expected to rise to 9 billion by 2045; at that rate, current trends suggest that half Earth’s land surface will be disturbed by 2025. To Barnosky, this is disturbingly close to a global tipping point.
“Can it really happen? Looking into the past tells us unequivocally that, yes, it can really happen. It has happened. The last glacial/interglacial transition 11,700 years ago was an example of that,” he said, noting that animal diversity still has not recovered from extinctions during that time. “I think that if we want to avoid the most unpleasant surprises, we want to stay away from that 50 percent mark.”
The San Francisco Gate pulls out more specifics on the factors contributing to the "tipping point" cited in the report:
- The rapid growth in the world's human population - to 9 billion or more by 2050 and possibly 27 billion by the end of the century - is quickly consuming available resources.
- Fossil fuels are being burned at a rapidly increasing rate, increasing concentrations of carbon dioxide in the atmosphere by 35 percent since the industrial revolution began. At the same time, ocean acidity has risen by 5 percent in the past 20 years.
- Ocean productivity is being diminished by vast "dead zones" where no fish swim, while 40 percent of Earth's land mass that was once "biodiverse" now contains far fewer species of crop plants and domestic animals.
- More animal species than ever are becoming extinct, and many plant and animal species are being forced by global warming to seek new ranges that could place them at risk of extinction, as well.
- Within the next 60 years, the average global temperature "will be higher than it has been since the human species evolved."
The Gate also states though that MIT researcher Richard Lindzen, who was not involved in the study, saying the likelihood of these events happening are "highly implausible." On the flip side, the Chronicle for Higher Education reports Paul Ehrlich, a professor of population studies at Stanford, saying the predictions made in the study don't go far enough -- they're "a little too optimistic."
The paper emphasizes the need for improved models to better predict how the planet will react to quickly changing conditions. In this video, Branosky discusses the Berkeley Initiative for Global Change Biology, which working on models to reach these predictions: