A recent study has shown that humans were big emitters of greenhouse gasses long before the Industrial Revolution took place, a finding that changes the benchmark that measures global warming.
The study, which was published on Wednesday, has found that emissions of methane in the 1,800 years before the industrial revolution rose in line with expanding populations, human conquest, and new agricultural techniques, reports The Associated Free Press.
The leader of the study is Celia Sapart of Utrecht University in the Netherlands. She, along with her colleagues, studied 56 ice core samples that were drilled in north and central Greenland for levels of carbon 13 (a telltale methane isope).
They took the data and overlaid it against other tables, including deforestation and charcoal found in sediment (indicators of human activity and wildfires). The analysis uncovered that between 100 BC and 1600 AD, 28 extra billion tonnes of methane were added to the atmosphere each year, meaning that the ancient Romans and Chinese are at least partially responsible for our global warming problem now.
While the amount pales in comparison with our methane production today (we produce about 28 billion tonnes per year just in landfills — about six percent of our total).
The major contributors to methane production in ancient times would likely have been deforestation, biomass burning, and rice paddies.
The Los Angeles Times notes that the total amount of methane production today is 70 times greater than it was 2,000 years ago, but the findings still suggest that man’s footprint on climate change is larger than they previously suspected. Celia Sapart stated:
“The quantities are much smaller, because there were fewer people on Earth. But the amount of methane emitted per person was significant.”
The core samples showed that the first period of methane production found in the ice cores was during the tail ends of both the Roman Empire and the Han Dynasty, when they preferred using charcoal as fuel. The next period was during the Medieval Climate Anomaly, which is roughly between 800 and 1200. The third period was between 1300 and 1600 during what scientists call the Little Ice Age. The authors stated:
“The results show that between 100 BC and AD 1600, human activity may have been responsible for roughly 20-30% of the total pyrogenic methane emissions.”
Ed Dlugokencky, a methane expert at the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory in Boulder, Colorado, who was not involved in the study, believes:
“The study gives further evidence for a contribution to the global methane burden from anthropogenic sources.”
While the study has helped to answer long-held questions about the ancient world and methane emissions, there is still a lot to be done about the future. This year the arctic ice cap saw the most drastic loss it has experienced in years. Sapart stated:
“To date, we do not know how natural methane sources will evolve together with human-induced climate change, but it is likely those natural sources will increase.”
Knowing that, according to this study, the ancient Romans and Chinese helped to contribute to global warming without the use of coal plants and other emissions sources we have now, do you think there is any hope for halting harmful emissions that cause global warming?