It appears that the Romans and China's Han Dynasty were the original greenhouse gas emitters.
Man-made climate change may have been around for a lot longer than previously thought. According to a study by an international team of scientists published in a recent edition of the journal “Nature”, Greenland’s ice has revealed an increasing level of heat-trapping methane about 2,000 years ago, remaining at that higher level for about two hundred years.
Roman climate protection? Image: Duncan Harris |
The culprits appear to have been the Romans and China’s Han dynasty. According to lead author Celia Sapart of Utrecht University in the Netherlands, land clearance for farming and the use of charcoal as fuel, for example to smelt metal to make weapons, probably caused the release of significant volumes of methane.
This discovery challenges a UN panel of climate scientists’ findings that climate change began during the Industrial Revolution with the rapidly increasing use of fossil fuels. The new findings have indicated that 10% of the total rise in levels of methane for the past 2,000 years happened before 1800, with the remaining 90% occuring after that period.
In a redrawing of the historic timeline of the rise in greenhouse gases, the team of scientists from the Netherlands, Switzerland, Denmark, the United States and France have described a second rise in methane in Medieval times as Europe’s economy emerged from the Dark Ages, coinciding with a warm period from 800-1200. This was possibly due to an increase in population in Asia and Europe leading to greater deforestation for farming.
The third rise may well have tracked major historic events such as the Black Death (not usually noted as a positive period of history) which saw a drop in levels. A further rise happened around the beginning of the Little Ice Age in the 1500s, with strong population growth after the plague.
The UN panel of scientists has said that the build-up of greenhouse gases is causing a rise in temperatures which in turn causes droughts, floods and rising sea levels. The biggest culprit today - according to UN statistics - is China, ahead of the US, EU, India and Russia.