Increasing temperatures in the United Kingdom are resulting in the soil releasing high amount of carbon dioxide, and thus contributing to global warming, scientists said after analyzing soil samples from all over the country.
“Our findings suggest the soil part of the equation is scarier than we had thought. The consequence is that there is more urgency about doing something - global warming will accelerate,” said Guy Kirk, the lead author of the study from Cranfield University.
Soils contain large amounts of carbon, almost twice that in vegetation or the atmosphere and these amounts remain constant due to carbon from decayed leaves and wood entering the soil. But the study found that this balance has been disturbed.
“It had been reckoned that the CO2 fertilization effect was somehow offsetting about 25 per cent of the direct human induced carbon dioxide emissions. It was reckoned that the soil temperature emission effect would catch up in maybe 10 to 50 years' time. We are showing that it seems to be happening rather faster than that,” Kirk said.
Researchers said the soil in UK has been losing carbon at the rate of 4 million ton a year for the past two and a half decades. This means that all the cuts that were made in UK’s industrial carbon emissions, under the Kyoto Protocol, between 1990 and 2002 stand mitigated.
“These losses completely offset the past technological achievements in reducing carbon dioxide emissions, putting the UK's success in reducing greenhouse gas emissions in a different light,” said Detlef Schulze and Annette Freibauer of the Max Planck Institute, who reviewed the study.
Kirk, along with his team, sampled the top 15 cm of soil at 6,000 points of England and Wales between 1978 and 2003. Around 40 per cent of these sites were sampled more than once at different times. The team found that the soils at these places had lost 0.6 per cent of their carbon content per year. They also said that the temperature in the UK had gone up by 0.5 degrees centigrade in the last 25 years.
The authors attributed the changes to global warming, as they were unable to pinpoint any other factor that might facilitate changes like these in non-agricultural soil.
Schulze and Freibauer said the new findings had ‘considerable’ scientific and political implications. “Further research into the carbon cycle and on reducing CO2 emissions must take full account of areas where large pools of organic carbon are stored - or are being released. If we intend to stabilize the climate, such areas require much more serious consideration,” they said.
