In today’s world, coal is associated with Earth’s rapid warming – but, millions of years ago, its formation nearly turned our planet into a massive ‘snowball.’
Roughly 300 million years ago, much of the world was covered in the vast forests of the Carboniferous and Permian periods.
And, as these ancient trees died off, the massive amounts of carbon dioxide they’d absorbed during life was buried beneath the surface, creating the coal that’s used today.
Researchers have now discovered that this effect was so dramatic, it caused Earth’s CO2 concentration to plummet, nearly sending the planet into a period of global glaciation.
Roughly 300 million years ago, much of the world was covered in the vast forests of the Carboniferous and Permian periods. And, as these ancient trees died off, carbon dioxide was buried beneath the surface, creating the coal that’s used today. Stock image
As the trees died out, the debris left behind on the forest floor was buried over time, taking the CO2 they’d sequestered beneath the surface.
In the new study, researchers used computer simulations to plot the changes in Earth’s past climate.
Some of these changes could be linked to Earth’s tilt and its movement around the sun – but, the team found CO2 concentrations had a major impact as well.
At some points, the ancient soils and fossil leaves reveal atmospheric CO2 dropped to about 100 parts per million.
Global glaciation, according to the researchers, occurs below 40 parts per million.
‘It is quite an irony that forming the coal that today is a major factor for dangerous global warming once almost led to global glaciation,’ said author Georg Feulner, from the Potsdam Institute for Climate Impact Research.
‘However, this illustrates the enormous dimension of the coal issue.
Researchers have now discovered that this effect was so dramatic, it caused Earth’s CO2 concentration to plummet, nearly sending the planet into a period of global glaciation. Stock image
‘The amount of CO2 stored in Earth’s coal reserves was once big enough to push our climate out of balance.
‘When released by burning the coal, the CO2 is again destabilizing the Earth system.’
Atmospheric carbon dioxide has come a long way in the millennia that have passed.
Now, levels have surpassed 400 parts per million – a milestone said to be a tipping point for climate change.
EARTH’S ‘COAL FORESTS’
The remains of these ancient steamy jungles are now compacted in underground coal seams, after many years of decay and peat accumulation.
During the Carboniferous Period, marine fish began to colonize freshwater swamps by the masses.
Orthacanthus dominated the waters of the ‘Coal Forests,’ illustrated above, roughly 300 million years ago
According to the researchers, the study highlights just how strongly this greenhouse gas can effect the processes on Earth.
‘We should definitely keep CO2 levels in the atmosphere below 450 parts per million to keep our climate stable, and ideally much lower than that,’ said Feulner.
‘Raising the amount of greenhouse gases beyond that limit means pushing ourselves out of the safe operating space of Earth.
‘Earth’s past teaches us that periods of rapid warming were often associated with mass extinction events.
‘This shows that a stable climate is something to appreciate and protect.’