24 March 2016, Climate News Network, Humans tilt climate books out of balance. Greenhouse gases from cattle, fertilisers, manure and agriculture mean that human activities have turned the land and soil into part of the global warming machine. In the great book-keeping of climate change, scientists have just discovered a big mistake. They have been wrong, they now think, to count on the mountains, the plains, the forests and the grasslands as an agency that slows climate change by absorbing carbon dioxide. It does absorb carbon dioxide. But the chilling news is that the soil itself may be making the world warmer. That is because humans have changed the way the landscape and its living things works, and now – thanks to those other greenhouse gases, methane and nitrous oxides, from cattle, fertilisers, manure and agriculture – the terrestrial biosphere is actually accelerating climate change. Twenty-three scientists from 16 laboratories and institutions report in Nature journal that they re-examined the sums on which climate forecasts depend. They concluded: “We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010.” Read More here
Tag Archives: Agriculture
10 March 2016, The Conversation, Global food production threatens to overwhelm efforts to combat climate change. Each year our terrestrial biosphere absorbs about a quarter of all the carbon dioxide emissions that humans produce. This a very good thing; it helps to moderate the warming produced by human activities such as burning fossil fuels and cutting down forests. But in a paper published in Nature today, we show that emissions from other human activities, particularly food production, are overwhelming this cooling effect. This is a worrying trend, at a time when CO₂ emissions from fossil fuels are slowing down, and is clearly not consistent with efforts to stabilise global warming well below 2℃ as agreed at the Paris climate conference. To explain why, we need to look at two other greenhouse gases: methane and nitrous oxide. The other greenhouse gases Each year, people produce about 40 billion tones of CO₂ emissions, largely from burning fossil fuels and deforestation. This has produced about 82% of the growth in warming due to greenhouses gases over the past decade. The planet, through plant growth, removes about a quarter of this each year (another quarter goes into the oceans and the rest stays in the atmosphere and heats the planet). If it didn’t, the world would warm much faster. If we had to remove this CO₂ ourselves, it would cost hundreds of billions of dollars each year, so we should be very grateful that the Earth does it for free. Apart from CO₂, there are two other main greenhouse gases that contribute to global warming, methane (CH₄) and nitrous oxide (N₂O). In fact, they are both more potent greenhouse gases than CO₂. The global warming potential of methane and nitrous oxide is 28 and 265 times greater than that of CO₂, respectively. The human emissions of these gases are largely associated with food production. Methane is produced by ruminants (livestock), rice cultivation, landfills and manure, among others. Read More here
10 March 2016, Science Daily, Cutting cattle carbon: Bad breath and flatulence. Cattle have bad breath and commonly suffer from severe, chronic flatus generating large amounts of methane, which is a greenhouse gas and a driver of anthropogenic global warming. There is an obvious answer to this problem, stop breeding cattle. Unfortunately a large proportion of us enjoy our bovine dairy products and meat too much. Until synthetic products that are indistinguishable from the real thing become available and accepted by milk drinkers and steak fans, we will have to look into alternative approaches to reducing the carbon emissions from these creatures. Writing in International Journal of Global Warming, Abdelmajid Moumen, Ghizlane Azizi, Kaoutar Ben Chekroun and Mourad Baghour of the Université Mohamed 1er, in Nador, Morocco, have reviewed the various approaches to reducing methane emissions from cattle and other livestock. These approaches involve improved genetic selection through breeding, modification of dietary composition, or through rumen microbial manipulation, vaccines against the methanogenic bacteria that generate the methane in these animals and various other techniques. It is possible that among the approaches or with a combination of approaches there might be a way to reduce the global burden of methane emissions from livestock. Read More here
22 February 2016, The Conversation, Queensland land clearing is undermining Australia’s environmental progress. Land clearing has returned to Queensland in a big way. After we expressed concern that policy changes since 2012 would lead to a resurgence in clearing of native vegetation, this outcome was confirmed by government figures released late last year. It is now clear that land clearing is accelerating in Queensland. The new data confirm that 296,000 hectares of bushland was cleared in 2013-14 – three times as much as in 2008-09 – mainly for conversion to pastures. These losses do not include the well-publicised clearing permitted by the government of nearly 900 square kilometres at two properties, Olive Vale and Strathmore, which commenced in 2015. Map showing the amount of habitat for threatened species cleared between 2012 and 2014. WWF. Alarmingly, the data show that clearing in catchments that drain onto the Great Barrier Reef increased dramatically, and constituted 35% of total clearing across Queensland in 2013-14. The loss of native vegetation cover in such regions is one of the major drivers of the deteriorating water quality in the reef’s lagoon, which threatens seagrass, coral reefs, and other marine ecosystems. The increases in land clearing are across the board. They include losses of over 100,000 hectares of old-growth habitats, as well as the destruction of “high-value regrowth” – the advanced regeneration of endangered ecosystems. These ecosystems have already been reduced to less than 10% of their original extent, and their recovery relies on allowing this regrowth to mature. Alarmingly, our analysis of where the recent clearing has occurred reveals that even “of concern” and “endangered” remnant ecosystems are being lost at much higher rates now than before. Read More here