According to a decade long study by the scientists, every year human activities, including the burning of fossil fuels and deforestation, release 40 to 100 times more planet-warming CO2 than all the volcanoes on Earth, AFP reported Tuesday.
Deep Carbon Observatory (DCO) is a global team of around 500 scientists, and these findings are part of a 10-year study. The team produced a series of papers on an in-depth account of the Earth’s carbon, released in the journal Elements on Tuesday detailing on how carbon gets stored, emitted and reabsorbed by natural as well as human-made processes.
DCO said, compared to volcanoes and other natural processes that release 0.28 to 0.36 gigatonnes of carbon dioxide per year, human activity released more than 37 gigatonnes in 2018 alone, according to AFP. As DCO explained in a press release, annual human emissions are 40 to 100 times more than those of volcanoes in total.
“Climate sceptics really jump on volcanoes as a possible contender for top CO2 emissions but it’s simply not the case,” Professor of Volcanology and Petrology and Ron Oxburgh Fellow in Earth Sciences at Queens’ College, Cambridge Marie Edmonds told AFP.
“In the past we see that these big carbon inputs to the atmosphere cause warming, cause huge changes in both the composition of the ocean and the availability of oxygen,” Marie said.
“The amount of CO2 pumped into the atmosphere by anthropogenic (manmade) activity in the last 10-12 years (is equivalent) to the catastrophic change during these events we’ve seen in Earth’s past,” Edmonds told AFP.
Anthropogenic carbon releases were not the only parameters that the study focused on. However, they provided a general account of where carbon of the entire Earth gets stored and about its movement through the environment, as BBC News explained. The majority of Earth’s 1.85 billion gigatonnes of carbon is below the ground, with two thirds in the core and just 43,500 billion tonnes (approximately 47,951 U.S. tons) are above the ground in the oceans, land, and atmosphere representing just two-tenths of 1% of total carbon of Earth.
One gigatonne is equivalent to around 3 million Boeing 747s.
To understand the movement of carbon through the Earth’s systems over time, the researchers also investigated geological history in order. The findings are that over the past 500 million years, the planet has been maintaining balance by drawing down the same amount of carbon into the ground as it has released. However, as per the explanation of EOS, a few notable exceptions were there which are as follows:
“In the past 500 million years, four volcanic eruptions created large igneous provinces (LIPs) that each released massive quantities of CO2 over tens of thousands of years. These LIPs caused the above-ground quantity of CO2 to spike to about 170% of its steady state value, which led to warmer surface conditions, more acidic oceans, and mass extinctions.
“Likewise, large impact events, including the Chicxulub impact 65 million years ago, released large quantities of carbon from the subsurface into the atmosphere”.
The Chicxulub impact was the event that occurred 65 million years ago, and that most likely drove the dinosaurs to extinction, killing off three-quarters of all life on Earth, and releasing between 425 and 1,400 gigatonnes of CO2, the team estimated. It’s worrying that human activity is releasing carbon dioxide at a slightly higher rate today, EOS reported.
“It’s really revealing that the amount of carbon dioxide we’re emitting in a short time period is very close to the magnitude of those previous catastrophic carbon events,” Dr. Celina Suarez from the University of Arkansas told BBC News. “A lot of those ended in mass extinctions, so there are good reasons why there is discussion now that we might be in a sixth mass extinction.”
The Earth’s systems eventually rebalanced following past catastrophic carbon releases; however, it took much time.
“Climate deniers always say that Earth always rebalances itself,” Suarez told AFP. “Well, yes it has. It will rebalance itself, but not on a timescale that is of significance to humans.”
Apart from reminding of the severity of the climate crisis, the research also uncovers some potentially life-saving information such as before the eruption volcanoes often discharge certain gasses.
“A shift in the composition of volcanic gases from smelly (akin to burnt matches) sulfur dioxide (SO2) to a gas richer in odorless, colorless CO2 can be sniffed out by monitoring stations or drones to forewarn of an eruption—sometimes hours, sometimes months in advance,” DCO explained. “Eruption early warning systems with real-time monitoring are moving ahead to exploit the CO2 to SO2 ratio discovery, first recognized with certainty in 2014.”