Methane emissions shot up in the previous decade, according to a new international study, which will hurt the fight against global warming.

According to the study released by the Global Carbon Project, methane levels rose slowly from 2000 to 2006, then jumped ten times as fast in the following decade. There was an especially high jump in methane levels in 2014 and 2015. In that two-year period methane concentrations jumped by 10 or more parts per billion (ppb) annually, versus an average increase of 0.5ppb during the early 2000's.

"We should do more about methane emissions. If we want to stay below a 2 degrees Celsius temperature increase, we should not follow this track and need to make a rapid turnaround," said Marielle Saunois, lead author of the study and assistant professor at the Université de Versailles Saint-Quentin.

Methane is less prevalent in the atmosphere than carbon dioxide, the main greenhouse gas, but it captures 28 times more heat than carbon dioxide. Saunois said the reason why there has been a surge in methane was not known, but most likely sources are cattle ranching and rice farming. Cows expel methane and flooded soils of rice paddies create microbes that produce methane. Saunois said data from the United Nations' Food and Agriculture Organization showed livestock production expanded from roughly 1.3 billion cattle in 1994 to nearly 1.5 billion 20 years later, and there was a similar increase in rice production.

Robert Jackson, a co-author of the paper and professor in the Earth System Science at Stanford University said methane can come from many sources, including natural sources. Roughly 60 percent is thought to be rooted in human activities such as farming.

"When it comes to methane, there has been a lot of focus on the fossil fuel industry, but we need to look just as hard, if not harder, at agriculture," said Jackson.

Silent underground helpers Half truths The story goes that when an earthworm is split in two, both parts will live on. That's not exactly right. Only the front of the worm can survive such a trauma. Even then, it doesn't always make it. All of the worm's vital organs are here but if too much of the gut is missing or the wound becomes infected, the half worm won't recover.

Silent underground helpers Conscientious composter Worms satisfy their hunger with the remnants of dead plants. They also graze on bacteria, algae, single-cell organisms and fungal threads located in their tunnels. Because earthworms have no teeth, they compost organic material by sticking food to the walls of underground burrows and layering excrement over it. This creates a perfect environment for pre-digesting microorganisms.

Silent underground helpers Soil stabilizers The earthworm's cast material – also known as worm poop – helps create good soil's fine crumb structure. Each year, the animals will lay a 0.5 centimeter crumb layer on the soil surface. But if they are really industrious and conditions are right, it can be up to five centimeters. These casts are packed full of nutrients that provide food for fungi and help prevent soil erosion.

Silent underground helpers Has an earthworm got a head? Earthworms have a head and tail, although that may be hard to tell at first glance. If the animal is at reproductive age, a thick band, called a clitellum, is visible. The head is located closest to this band.

Silent underground helpers Tiny tunnellers An earthworm's tunnel system is a big boon to the soil. It allows water to flow more quickly through the ground and provides ventilation. Plants also push their roots through the many, many tunnels created by earthworms. A 50-hectare farm can house up to 400,000 kilometers of underground passages.

Silent underground helpers Dangers above ground An earthworm's true domain, as its name betrays, is underground. But at times, the animal is lured above ground by the vibration of raindrops hitting the earth's surface. There, dangerous UV-light and hungry birds await.

Silent underground helpers Prime plumbers A ground without earthworms behaves like a blocked drain when it rains. Water can no longer flow down through the soil. Even the smallest amounts of water can cause flooding over time. However, when worms are present and working diligently, soil can deal with the intake of water and surplus liquid ends up in springs and wells.

Silent underground helpers Close quarters The number of earthworms living in the soil depends on how the land is cultivated. In monocultures, where many machines and pesticides are used, you'll find around 30 animals per square meter. But the same amount of soil on a farm that practices multi-cropping can contain up to 120 animals. In optimum conditions, up to several hundred of the invertebrates may be working silently underground.



kbd/msh (AFP, Reuters)