Greenhouse gas nitrous oxide emissions have ‘increased substantially’ in the past decade

Greenhouse gas nitrous oxide emissions have ‘increased substantially’ in the past decade

SOURCE: ABC (Australia) DATE: November 18, 2019 SNIP: Emissions of nitrous oxide — a greenhouse gas 300 times more potent than carbon dioxide — are going up faster than we thought. Nitrous oxide is a greenhouse gas 300 times more potent than carbon dioxide. This means each molecule of nitrous oxide in the atmosphere can capture 300 times more heat than a molecule of carbon dioxide. Nitrous oxide is emitted predominantly from agriculture using nitrogen fertiliser, and to a lesser extent burning fossil fuels and biofuels. It’s countries in east Asia and South America that are making the biggest contribution to the increasing emissions, according to a study published today in the journal Nature Climate Change. Natural sources of nitrous oxide include our oceans and rainforests, but it’s the human sources that are of most cause for concern — specifically agriculture, including nitrogen fertiliser use and livestock manure. We’ve known for decades that nitrous oxide emissions are increasing, but since 2009 there has been a “substantial increase” in these emissions, said Pep Canadell, executive director of the Global Carbon project and an author of the new research. It’s been known for a while that there isn’t a linear relationship between nitrogen fertiliser input and nitrous oxide emissions, said Richard Eckard, director of the Primary Industries Climate Challenges Centre at the University of Melbourne. “When you exceed the [plant] system’s capacity to use that nitrogen fertiliser, the efficiency goes out the window, and the nitrogen can leak out of the cycle,” Professor Eckard said. “That plays out in some industries where the recommended amount of fertiliser is exceeded, and you...
No laughing matter

No laughing matter

SOURCE: Harvard Gazette DATE: June 6, 2019 SNIP: About a quarter of the Northern Hemisphere is covered in permafrost. Now, it turns out these permanently frozen beds of soil, rock, and sediment are actually not so permanent: They’re thawing at an increasing rate. Human-induced climate change is warming these lands, melting the ice and loosening the soil, and that can cause severe damage. Forests are falling; roads are collapsing; and, in an ironic twist, the warmer soil is releasing even more greenhouse gases, which could further exacerbate the effects of climate change. Shortly after scientists first noticed signs of thaw in the early 1970s, they rushed to monitor emissions of the two most influential greenhouse gases — carbon dioxide and methane. But until recently, the threat of the third-most-prevalent gas, nitrous oxide (N2O) — known in dentistry as laughing gas — has largely been ignored. In a 2010 paper, the Environmental Protection Agency (EPA) rated permafrost nitrous oxide emissions as “negligible,” and few studies counter this claim. But a paper published this month in the journal Atmospheric Chemistry and Physics shows that nitrous oxide emissions from thawing Alaskan permafrost are about 12 times higher than previously assumed. Since N2O traps heat nearly 300 times more efficiently than carbon dioxide does, this revelation could mean that the Arctic — and the global climate — are in more danger than we thought. “Much smaller increases in nitrous oxide would entail the same kind of climate change that a large plume of CO2would cause,” said Wilkerson, the paper’s first author and a Ph.D. student at the Graduate School of Arts and Sciences...
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...
Draining peatlands gives global rise to greenhouse laughing-gas emissions

Draining peatlands gives global rise to greenhouse laughing-gas emissions

SOURCE: Science Daily DATE: March 28, 2018 SNIP: Drained fertile peatlands around the globe are hotspots for the atmospheric emission of laughing-gas — a powerful greenhouse gas called nitrous oxide, which is partly responsible for global warming and destruction of the ozone layer, a new study shows. Research into natural peatlands such as fens, swamps and bogs, as well as drained peatlands, found that either draining wet soils or irrigating well drained soils boosts the emission of nitrous oxide significantly. Dr Sami UllahProf UÜlo Mander, Senior Lecturer in Biogeochemistry, at the University of BirminghamTartu, who conceived this research with a global network of 36 scientists said: “Nitrous oxide is no laughing matter — it is a significant contributor to global climate change and depletion of the ozone layer, which protects our planet from cosmic radiation. “Organic soils, such as fens, swamps, bogs and drained peatlands, make up more than one-tenth of the world’s soil nitrogen pool and are a significant global source of laughing gas. They are significant sources of nitrous oxide when drained for...
Global Warming Could Make This Lurking Climate Threat Even Worse

Global Warming Could Make This Lurking Climate Threat Even Worse

SOURCE: Forbes DATE: October 17, 2017 SNIP: A years-long study of Minnesota farm fields has found that emissions of nitrous oxide—a more dangerous greenhouse gas than carbon dioxide—will likely increase as our planet gets warmer. And our climate models aren’t ready. Like carbon dioxide, nitrous oxide (yes, the same stuff as laughing gas) traps heat in Earth’s atmosphere. Although it’s thought to account for only about 6% of the greenhouse effect today, it is about 300 times worse for the climate than CO2. One major source is runoff from farms and fields. Bacteria breaking down nitrogen compounds from manure and synthetic fertilizers generate nitrous oxide as a waste product. “There’s a lot of uncertainty about how nitrous oxide is going to respond to changing temperature and moisture levels,” says David Kanter, a professor of environmental studies at New York University who has studied nitrogen pollution. He was not involved in the new research. The answer appears to be...