October 18, 2012. Netherlands. New research suggests that the current model for measuring and predicting greenhouse gasses may be off a bit. It’s widely believed that humans had no impact until the industrial revolution in the 1800’s, and any change in greenhouse gas levels was the result of nature – volcanoes, forest fires, etc. Now, a study shows that those gasses were the result of humans, not nature. And that man has much more impact on global warming that currently believed.
Greenhouse gasses like methane by year.
Activity on Earth creates the green house gas methane, which has more than 20-times the warming power as fellow greenhouse gas carbon dioxide. Together, those gases create a bubble around the globe. That invisible bubble creates a greenhouse. Anyone who’s ever been in a greenhouse knows how hot they are inside compared to immediately outside. That, in its basic form, is the formula of global warming.
The current model plots out the greenhouse gas levels going back to ancient times. Any spikes or dips are attributed to natural occurrences such as warmer temperatures and higher rains, which increases the area of wetlands and their release of methane. Extra-normal volcanic activity is also attributed to some of the historic spikes in greenhouse gasses.
But a new model just released in the Netherlands suggests that way of thinking is wrong. It presents findings which show a direct connection between past methane spikes and documented human activity. What that means is the science community has drastically under-estimated mankind’s power when it comes to creating greenhouse gasses. Another way of putting it is, if iron-age man could cause the needle to move so much more than we thought, then modern man is making the needle move much more than we currently think we are.
"It was believed that emissions started in 1850,” study co-author Célia Sapart of Utretcht University said, “We showed that humans already started to impact greenhouse effects much before.” To capture samples of air from ancient times through today, the team drilled out huge cores of ice in Greenland and analyzed the tiny air bubbles captured in each previous age.
As detailed in the journal Nature and Yahoo News, researchers show that a spike in methane around 100 BC matched-up with the birth of the Roman Empire and its rapid expansion onto the world scene. Sapart suggests the spike was caused by massive land-clearings to make way for much needed farms and living space. At the same time, China’s Han Dynasty was burning thousands of acres of wood in their forges to make swords.
Romans, she explains, burned entire forests to clear land. Burning wood is one of the largest causes of methane release into the atmosphere. She also points out the timeframe of 200 AD, when the rapid Roman expansion came to a halt and the Han Dynasty collapsed, along with their wood-burning forges. At the same time, methane levels dropped as well.
The researchers also point to the year 1400, also known as the ‘mini ice age’. Methane levels spiked during that time frame and the scientists think they know why. Because when global temperatures dropped, humans were forced to burn wood on a widespread scale to keep warm. That massive increase in wood-burning for heat was enough to make methane levels and global warming spike on the charts.
Cow flatulence (cow farts and burps)
On the opposite side of the thermometer, the researchers point out various times in history when temperatures warmed up and the methane level spiked again. They suggest things such as cow flatulence is to blame. With warmer temperatures, populations exploded. With more mouths to feed, man relied on the widespread domestication of cows and other grazing animals.
As detailed by How Stuff Works, cow flatulence really does release methane gas, which in turn is one of the more devastating greenhouse gasses. Some researchers believe one cow releases as much greenhouse gas as one automobile. In fact, the site reveals that agriculture, including cows, is responsible for 14% of all greenhouse gas emissions.
In the Netherlands, the study’s co-author Célia Sapart reminds us why this discovery is so important, “The big goal of all this is to try to predict how greenhouse gas concentrations in the atmosphere are going to evolve in the future. Already at this period humans were emitting greenhouse gases, especially methane, so we need to reconsider what are natural conditions.”