Our earth is located in what scientists term the “Goldilocks Zone” because it is “just right.” If we were not located exactly where we are in the solar system and in the galaxy and in the universe, we probably would not exist. Extremophiles probably live in hostile environments throughout the universe, but mesophiles, like our species, need a stable and moderate habitat or they cannot survive.
There have been mass extinctions throughout the life of our planet with the Permian extinction having the distinction of killing off the most – about 90% of the species on earth at that time. Some scientists are concerned that we may be on the brink of a sixth major extinction since plants and animals are dying off anywhere from 100 to 1,000 times faster than they did before humans came on the scene.
Scientists at Duke University completed a study, published May 29, 2014, in the journal Science, that measured the rate at which species are disappearing from earth. In 1995, the researchers found that the pre-human rate of extinctions was roughly 1. Now, that rate is about 100 to 1,000.
Stuart Pimm, the study’s lead author, said habitat loss is mostly to blame for the increasing death rates. As humans continue to alter and destroy more land, animals and plants are increasingly being displaced from their natural habitats. Climate change is also a factor, he added.
So, with the balancing point of nature being “just right” on our planet, it probably does not take much to tip the balancing scales to one side or the other, which will have devastating effects to those species which cannot adapt in time.
There are many potential tipping points on our planet: (1) climate change, (2) ocean currents, (3) frozen methane, (4) buried black carbon, (5) permafrost and glacier melt, (6) hydrological cycle, (7) reduced sea ice, (8) draught, (9) bacteria resistant to penicillin, (10) proximity of sun, (11) proximity of moon, (12) volcanic activity, (13) pestilence, (14) movement of asteroid belt, and (15) other things that we may not even see coming, such as black energy and black holes.
Although global warming focuses on greenhouse gas as the culprit, there are other more significant sources of carbon that would be more dangerous tipping points that would contribute to major climate change that might lead to mass extinctions. These sources of carbon are black carbon buried in soil, methane frozen in water, and volcanic eruptions. In fact, the Permian extinction may have been caused by all three of these releases of carbon.
The most devastating of the three releases may be methane, which has an exponential impact. As the climate warms, more methane is released. As more methane is released, it causes our temperatures to go up higher than they would with releases of carbon dioxide. This melts more methane, causing even higher temperatures with a tipping point being reached with runaway releases like in the Permian period.
Researchers at the University of Wisconsin–Madison, have found that there is black carbon only about six and a half meters below the surface in Kansas, Nebraska, and other parts of the Great Plains where ancient soils are filled with black carbon and plants that have not yet fully decomposed. These carbon stores could be released into the environment via erosion, road construction, mining, or deforestation.
Erika Marín-Spiotta, a professor at UW-Madison and a coauthor of the study, which was published earlier this week in the journal Nature Geoscience, stated, “It was assumed that there was little carbon in deeper soil.” Since most soil studies do not penetrate deeper than 30 centimeters, scientists had dramatically underestimated underground carbon reserves that could be released into the air.
Erika explained that carbon reservoirs in buried soils can lurk in a range of environments—under dust accumulation, in floodplains, in valleys, at the foot of slopes of hills and mountains and under lava flows. She said they are likely to occur in many other parts of the world.
Marín-Spiotta said as much as 5.95 trillion pounds of carbon could be lurking in the depths of the Great Plains area her team looked at. That’s assuming the ancient soil forms a continuous layer across the region; the researchers were only able to collect measurements from specific points and don’t really know what portion of the region contains the carbon-rich soil.
This giant carbon bomb could be released over the next few decades as we clear cut more forests and see more erosion in draught-prone areas. We have already seen recent exposure to the atmosphere. But for the subterranean reserves, Marín-Spiotta believes a number of factors are at work, including how much carbon there really is, how much has persisted since it was buried, and what kind of carbon is down there.
Though Marín-Spiotta says the buried reserves carbon don’t pose an immediate risk to rising carbon dioxide levels in the atmosphere, but land managers need to take precautions, since the researchers found that the ancient soils are more reactive than was previously understood.
As with all tipping points, there can be multiple contributors to the final point of no return. And these contributors can have exponential effects on each other. We probably will not know when we have reached the tipping point, but our ancestors will not only know when that tipping point had been reached, but will also suffer the consequences.