12 October 2017, BBC News, Ozone layer recovery could be delayed by 30 years. Rising global emissions of some chlorine-containing chemicals could slow the progress made in healing the ozone layer.A study found the substances, widely used for paint stripping and in the manufacture of PVC, are increasing much faster than previously thought. Mainly produced in China, these compounds are not currently regulated. Experts say their continued use could set back the closing of the ozone hole by up to 30 years. Scientists reported last year that they had detected the first clear evidence that the thinning of the protective ozone layer was diminishing. The Montreal Protocol, which was signed 30 years ago, was the key to this progress. It has progressively helped governments phase out the chlorofluorocarbons and the hydrochlorofluorocarbons that were causing the problem. However, concern has been growing over the past few years about a number of chemicals, dubbed “very short-lived substances”. Antarctic ozone hole starts to ‘heal’ How Arctic ozone hole was avoided Weather ‘behind ozone hole changes’ Dichloromethane is one of these chemicals, and is used as an industrial solvent and a paint remover. Levels in the atmosphere have increased by 60% over the past decade. Read More here
Category Archives: Other Sources of GHG
29 September 2017, Carbon Brief, Analysis: What does revised methane data mean for the Paris Agreement? A study released today finds that global methane emissions from agriculture are much larger than previous estimates have suggested. Revised calculations find that methane emissions from livestock in 2011 were 11% higher than modelled estimates based on data produced in 2006 by the Intergovernmental Panel for Climate Change (IPCC). In response, media outlets including the BBC Radio 4 Today programme and Agence France-Presse (AFP) released reports suggesting that the findings could mean that it will be harder for countries to meet the goals of the 2015 Paris Agreement. Carbon Brief spoke to the authors of the new study, as well as scientists from the Priestley International Centre for Climate at the University of Leeds, and asked them to analyse these claims. What did the new study find? Methane is a potent greenhouse gas and the second biggest contributor to human-caused global warming after carbon dioxide. Livestock produce large amounts of methane as part of their normal digestive process, largely through passing wind. Also, when the animal manure is stored or managed in lagoons or holding tanks, more methane is released into the atmosphere. The extent to which methane emissions from agriculture could contribute to future global warming has been examined by international scientific bodies including the Intergovernmental Panel on Climate Change (IPCC) and the US Environmental Protection Agency (EPA). Read More here
12 December 2016, Climate News Network, Methane’s rapid spurt risks climate curbs plan. A recent rapid rise in methane could damage global attempts to slow climate change through cuts in carbon dioxide emissions. One year ago today, with huge relief, scarcely able to believe their achievement, world leaders finally agreed to reduce emissions of carbon dioxide. But a bare 12 months later comes sobering news: atmospheric concentrations of another gas, methane, are growing faster than at any time in the last 20 years, putting further pressure on the historic Paris Agreement to deliver substantial cuts in emissions very soon. Some scientists say the world now needs to change course and do more about methane to have a chance of keeping average global temperatures from rising by more than 2°C. And one seasoned Arctic watcher says the changes there in the last decade are altering a system which has remained intact since the Ice Age. Methane is the second major greenhouse gas, with agriculture accounting for 40% of emissions. Over a century it is 34 times more powerful as a greenhouse gas than carbon dioxide (though far less abundant), but over 20 years methane is 84 times more potent than CO2. In an editorial in the journal Environmental Research Letters, an international team of scientists reports that methane concentrations in the air began to surge around 2007 and grew steeply in 2014 and 2015. In those two years concentrations rose by 10 or more parts per billion annually. In the early 2000s they had been rising by an annual average of 0.5 ppb. Read More here
5 December 2016, The Conversation, Nitrogen pollution: the forgotten element of climate change. While carbon pollution gets all the headlines for its role in climate change, nitrogen pollution is arguably a more challenging problem. Somehow we need to grow more food to feed an expanding population while minimising the problems associated with nitrogen fertiliser use. In Europe alone, the environmental and human health costs of nitrogen pollution are estimated to be €70-320 billion per year. Nitrogen emissions such as ammonia, nitrogen oxide and nitrous oxides contribute to particulate matter and acid rain. These cause respiratory problems and cancers for people and damage to forests and buildings. Nitrogenous gases also play an important role in global climate change. Nitrous oxide is a particularly potent greenhouse gas as it is over 300 times more effective at trapping heat in the atmosphere than carbon dioxide. Nitrogen from fertiliser, effluent from livestock and human sewage boost the growth of algae and cause water pollution. The estimated A$8.2 billion damage bill to the Great Barrier Reef is a reminder that our choices on land have big impacts on land, water and the air downstream. Read More here