Humans have pushed atmospheric carbon dioxide to invisible heights in our short existence (geologically). But give us a few more generations, and our geological impact on the planet will be clear.
New discoveries released Wednesday show that, at current emission rates, we only have five generations left to create an unprecedented atmosphere for 56 million years. The last time carbon dioxide levels were as high as we want, helped create one of the biggest murders in the recent history of the Earth.
The Paleocene – Eocene Thermal Maximum (PETM) is a period of global history as disturbing as it may seem. Scientists have been studying it for years, looking for carbon isotopes, fossils and other clues buried in the Earth. Their findings show that carbon dioxide has increased rapidly, causing the Earth to warm up by 5 to 8 degrees Celsius (9 to 14.4 degrees Fahrenheit). The tropical Atlantic was probably 36 degrees Celsius (96.8 degrees Fahrenheit); nearly half of the microscopic foraminifers that inhabit the seas have died, land animals have perished or shrunk, and it took 150,000 years for Earth to recover from the shock. It's not exactly a dream climate, yet it seems to offer the closest equivalent to what humans are doing to the climate these days.
The new research, published in Geophysical Research Letters, shows how far we are on reaching the extremes of PETM and, in a way, how we have already passed it. Building on a series of studies on the beginnings of PETM and the speed with which carbon dioxide has accumulated in the atmosphere, Philip Gingerich, professor emeritus at the Department of Earth Sciences, said: the land of the University of Michigan, used models to project carbon emissions of humans in the future.
Although the PETM impulse of carbon dioxide has been geologically fast, it has nothing to do with what humans inflict on the atmosphere. Modern emission rates are up to 10 times faster than during PETM. However, while PETM emissions likely resulted from a mixture of volcanism, forest fires and methane escaping from permafrost and seabed, the current situation is almost entirely due to emissions. carbon from human activities. And these emissions continue to increase, the world establishing a new high level of carbon pollution last year. Based on this gloomy trend, Gingerich projected emissions into the future and found that in just 140 years, at current rates, we will have created the beginning of PETM atmosphere v2.0. In 259 years, we will reach the peak PETM.
This is a much worse scenario, which suggests that we are unlikely to reach this point. And yet, we have been living this scenario since the beginning of carbon dioxide records in 1959, when Gingerich began calculating future trends.
"[It’s] as if we were deliberately and efficiently producing carbon to be emitted into the atmosphere at a rate that will soon have consequences comparable to those of major events that occurred long ago in the history of the Earth He told Earther.
As the study aptly indicates, Gingerich's grandfather was born 140 years ago, whereas 259 years ago Ben Franklin invented a clock with hour, minute and second hands. While the world has shown little appetite for reducing emissions, there has been a lot of talk about how we should do it, you know, probably sooner than later. The new discoveries are a cruel reminder of what our grandchildren expect, if they are not.