Rice farming up to twice as bad for climate change as previously thought, study reveals

Rice farming up to twice as bad for climate change as previously thought, study reveals

SOURCE: The Independent DATE: September 10, 2018 SNIP: Rice farming is known to be a major contributor to climate change, but new research suggests it is far bigger a problem than previously thought. Techniques intended to reduce emissions while also cutting water use may in fact be boosting some greenhouse gases, meaning the impact of rice cultivation may be up to twice as bad as previous estimates suggest. Scientists at the US-based advocacy group the Environmental Defense Fund suggest the short-term warming impact of these additional gases in the atmosphere could be equivalent to 1,200 coal power plants. The main culprit is methane, a potent greenhouse gas emitted from flooded rice fields as bacteria in the waterlogged soil produce it in large quantities. However, there is another gas produced by rice fields that can have a harmful climate effect. Nitrous oxide, commonly known as laughing gas, is also produced by soil microbes in rice fields. “The full climate impact of rice farming has been significantly underestimated because up to this point, nitrous dioxide emissions from intermittently flooded farms have not been included,” said Dr Kritee Kritee from the Environmental Defense Fund, who led the research. Despite being a powerful greenhouse gas in its own right that traps even more heat in the atmosphere than methane over long time periods, most rice producing countries do not report their nitrous oxide...
Trump Administration Wants to Make It Easier to Release Methane Into Air

Trump Administration Wants to Make It Easier to Release Methane Into Air

SOURCE: New York Times DATE: September 10, 2018 SNIP: The Trump administration, taking its third major step this year to roll back federal efforts to fight climate change, is preparing to make it significantly easier for energy companies to release methane into the atmosphere. Methane, which is among the most powerful greenhouse gases, routinely leaks from oil and gas wells, and energy companies have long said that the rules requiring them to test for emissions were costly and burdensome. The Environmental Protection Agency, perhaps as soon as this week, plans to make public a proposal to weaken an Obama-era requirement that companies monitor and repair methane leaks, according to documents reviewed by The New York Times. In a related move, the Interior Department is also expected in coming days to release its final version of a draft rule, proposed in February, that essentially repeals a restriction on the intentional venting and “flaring,” or burning, of methane from drilling operations. Methane makes up only about nine percent of greenhouse gases, but it is around 25 times more effective than carbon dioxide in trapping heat in the atmosphere. About one-third of methane pollution is estimated to come from oil and gas operations. The forthcoming proposals from the E.P.A. and Interior Department would allow far more methane to leak from oil and gas drilling operations, environmentalists say. “These leaks can pop up any time, anywhere, up and down the oil and gas supply chain,” said Matt Watson, a specialist in methane pollution with the Environmental Defense Fund, an advocacy group. “The longer you go in between inspections, the longer leaks will go...
The US’ hidden methane problem

The US’ hidden methane problem

SOURCE: Climate Change News DATE: August 13, 2018 SNIP: Climate Home News analysis of government data has identified roughly 300 active and 200 abandoned coal mines, which are the source of almost one-tenth of US methane pollution. Methane has 34 times the long-term warming effect of carbon dioxide and accounts for 10% of US greenhouse gas emissions. Its emissions from the oil and gas industry and the efforts of the Trump administration to roll back regulations on them have been widely publicised. Meanwhile, US coal mines released 60.5 MMTCO2e of methane in 2016, with roughly the same warming impact as 13 million cars. Efforts to control the problem are being hampered despite those with the technical expertise claiming a whole industry could be built on capturing these emissions and turning them into electricity. The data shows many of the most gaseous abandoned mines are in Kentucky and West Virginia and belonged to large operators such as Alpha Natural Resources, which also did not respond to requests for comment, and Alliance Resource Partners. Sealing shafts and allowing abandoned mines to flood can significantly decrease methane emissions. Even as US coal production has plummeted over the past decade, and the number of active mines halved, coal mine methane emissions fell at a much slower pace, EPA data published in April shows. This indicates mines are not being fully sealed as they shut down. The EPA estimates that by 2020 coal mines will release methane with the equivalent warming impact of 166 coal-fired power plants. China, the world’s largest emitter, will account for nearly 53% of these emissions, while US mines will...
Mangroves and their deforestation may emit more methane than we thought

Mangroves and their deforestation may emit more methane than we thought

SOURCE: Mongabay DATE: July 13, 2018 SNIP: Mangroves, the dense tangled forests that buffer land from sea in many coastal areas of the tropics, are renowned for their ability to store carbon and help fight climate change. But new research finds mangroves may emit more carbon as methane than previously estimated – emissions made even worse by deforestation. The ability of mangroves to sequester carbon in the ground – termed “blue carbon” – is unparalleled, with previous research finding a tract of mangrove can bury 40 times more carbon than a similarly sized area of rainforest. Their results, published in Science Advances, reveal that mangrove soil carbon doesn’t remain stored in perpetuity. Some of it is transformed from carbon dioxide (CO2) to methane (CH4) by tiny microorganisims called archea, and is then released back into the atmosphere. Methane has a much bigger warming impact than carbon dioxide – 34 to 86 times more powerful – so even a bit of methane has the potential to offset mangrove CO2 storage. Ultimately, the team found that the methane released from mangrove soil carbon offsets blue carbon burial rates by an average of 20 percent. They say their results show that methane emissions should be factored into carbon accounting when evaluating the carbon storage potential of mangrove forests. The researchers say that deforestation has the potential to increase these emissions. Mangroves around the world are being deforested at a fast clip, with between 30 and 50 percent lost over the past half-century to agriculture, aquaculture and infrastructure...
Permafrost and wetland emissions could cut 1.5C carbon budget ‘by five years’

Permafrost and wetland emissions could cut 1.5C carbon budget ‘by five years’

SOURCE: Carbon Brief DATE: July 9, 2018 SNIP: Emissions of CO2 and methane from wetlands and thawing permafrost as the climate warms could cut the “carbon budget” for the Paris Agreement temperature limits by around five years, a new study says. These natural processes are “positive feedbacks” – so called because they release more greenhouse gases as global temperatures rise, thus reinforcing the warming. They have previously not been represented in carbon budget estimates as they are not included in most climate models, the researchers say. The findings suggest that human-caused emissions will need to be cut by an additional 20% in order to meet the Paris Agreement’s 1.5C or 2C limits, the researchers estimate. … The researchers then used the model to simulate the response of permafrost and natural wetlands to climate change. When the additional CO2 and methane emissions are incorporated, the available carbon budget shrinks substantially – falling to 533bn-753bn tonnes of CO2 for 1.5C, or 14-20 years of emissions. That means accounting for the impacts of permafrost and wetlands takes around five years off the 1.5C budget. And, as the table below shows, the budgets for the 1.5C overshoot and 2C scenarios are similarly...