Based upon the levels of CO2 in the atmosphere, which could continue to be released, the Earth may be heading toward conditions like those of the Paleocene-Eocene event. If this is the case, species might not be able to adapt to the extreme rate of current rise in greenhouse gases and temperatures.
The incredible rate at which the Arctic Sea ice is disappearing, the melting of Greenland and west Antarctic ice sheets, and heat waves, increased flooding, forest fires, and other extreme weather events may signify a major and irreversible shift in the state of the climate.
Mass extinctions have been happening since at least 580 million years ago, mainly due to escalating CO2 levels. Based on current levels, there is no precedence for the rapid escalation. All evidence points to another wave of extinctions in the relatively near future.
Science Express has determined that land and marine species disappear from the fossil record within 20,000 to 30,000 years from the time evidence for the eruption of large magma flows appears, approximately 201 million years ago. These volcanic eruptions increased atmospheric CO2 and increased ocean acidity.
Toward the end of the Triassic Period, large increases of CO2 from volcanoes caused a major climate shift, leading to mass extinction of approximately 34% of species. These extinctions gave birth to a climate that allowed the rise of dinosaurs during the Triassic Period, approximately 250-200 million years ago.
CO2 levels had risen to near 396.80ppm at Mauna Loa Atmospheric Observatory by February 2013. In February 2012, levels were 393.54ppm. The 3.26ppm per year rise is the highest increase known.
The Arctic atmosphere has a recorded measurement of 440ppm. This means that the upper limit for the Antarctic ice sheet, between 500 to 600 ppm, would be reached by late 2013.
Global carbon reserves contain more than 10,000 billion tonnes of carbon. If high rates of carbon are released into the atmosphere, this can raise CO2 levels to higher than 1000ppm, which would cause a rise in atmospheric radiative forcing similar to the Paleocene-Eocene boundary thermal maximum (PETM), which happened about 55 million years-ago. However the earth’s current rise surpasses that thermal maximum by about ten times.