Earthworms to be Blamed for Global Warming

Global warming has become a topic of worldwide concern, and it is taken for granted that human activities are the major contributor to climate change. But a new study has discovered an unexpected contributor to climate change.

It is the earthworms. Unlike their size, the impact of these tiny creatures is huge. The new study conducted by a research team from the University of California, Davis, suggests that earthworms increase greenhouse gas emissions from the soil. They noticed that the earthworms do not stimulate carbon sequestration in soil, which reduces greenhouse gas emission. Instead, they increase greenhouse gas emission through different ways.

"There was a hypothesis that earthworms were having a positive effect on the greenhouse balance, but they don't," co-author Johan Six, a plant sciences professor at UC Davis during the study who is now a professor at ETH Zurich in Switzerland, was quoted as saying in Phys.Org.

Conducted by a collaboration of scientists from the Netherlands, UC Davis, Dublin and Colombia, the researchers state after conducting some 57 experiments that earthworms should not get the credit for reducing greenhouse gases.

The researchers noticed that the earthworms increase the emission of nitrous oxide from soil by 42 percent, and carbon dioxide emission was increased by 33 percent. But they failed to track whether the earthworms affected the carbon stored inside the soil.

Explaining how earthworms increase greenhouse gas emission, the researchers state that they combine with the plant residues present in the soil and this increases decomposition and carbon dioxide emission. The gut of the earthworm plays the role of an incubator, thereby enhancing the activity of the nitrous oxide that produces microbes. When the earthworms burrow through the soil, they make way for the greenhouses gases to escape into the upper atmosphere.

Minor alterations in soil greenhouse gas dynamics can have important consequences on global warming, Dr. Jan Willem van Groenigen of Wageningen University said.

"We need more experiments that include growing plants, as well as more long-term studies and more field studies before we can decide to what extent global worming leads to global warming," lead author of the study Ingrid Lubbers of Wageningen University, Netherlands, was quoted as saying in Irish Times.