Poster's note : newscientist coverage top, journal abstract below Newscientist
Fall of USSR locked up world's largest store of carbon by Michael Slezak The fall of the Soviet Union created the largest ever human-made carbon sink - abandoned farmland. In 1991, the USSR formally split into separate republics. The subsequent collapse of industry reduced the amount of greenhouse gas emissions Russia produced - helping it to easily meet the climate targets set by the Kyoto protocol But as well as cutting emissions, the fall had another effect. The privatisation of land led to one of the biggest land-use changes of the 20th century. Huge tracts of farmland were abandoned when the collectivised farming system introduced by Stalin collapsed, and farmers simply left the land and headed for the cities. Ever since, plants have been reclaiming the land and locking in carbon as they grow. Researchers have tried to put a figure on the size of this effect but estimates have varied dramatically, and haven't always taken account of the fact that plants grow at different rates on different types of soil and lock up more carbon as they grow larger. To get an answer to how much carbon is sequestered in Russian territory, Irina Kurganova from the Russian Academy of Sciences in Pushchino and colleagues mapped the distribution of soil types for the Russian part of the former USSR and overlaid it with a map of land-use change. They then looked at every study of carbon storage they could find and collated them to estimate the amount of carbon captured at each point on their map. Largest human-made sink They found that in total, the 455,000 square kilometres of land abandoned in the part of the USSR that is now Russia has locked away an average of 42.6 million tonnes of carbon every year since 1990. This means that each year, the land has been locking away the equivalent of 10 per cent of Russia's carbon dioxide emissions from fossil fuels, the researchers calculate. "Everything like this makes a difference," says Jonathan Sanderman, a soil chemist at CSIRO Land and Water in Australia. "Ten per cent is quite a bit considering most nations are only committed to 5 per cent reduction targets. So by doing absolutely nothing - by having depressed their economy - they've achieved quite a bit." He says the abandoned farmland is probably the largest human-made carbon sink, but notes it came at the cost of enormous social and economic hardship. Modelling the effect into the future, Kurganova estimates that, since the land has remained uncultivated, another 261 million tonnes will be sequestered over the next 30 years. At this point, the landscape will reach equilibrium, with the same amount of carbon escaping into the atmosphere as She adds that the stored carbon should now be taken into account if recultivation of the land is contemplated. ============= Journal article : Global Change Biology, doi.org/n2k Carbon cost of collective farming collapse in Russia - Kurganova - Global Change Biology - Wiley Online Library http://onlinelibrary.wiley.com/doi/10.1111/gcb.12379/abstract Carbon cost of collective farming collapse in Russia Irina Kurganova, Valentin Lopes de Gerenyu, Johan Six, Yakov Kuzyakov DOI: 10.1111/gcb.12379 Keywords: organic carbon stocks;soil carbon sequestration;land use change;meta-analysis;Russian Federation Abstract The collapse of collective farming in Russia after 1990 and the subsequent economic crisis led to the abandonment of more than 45 million ha of arable lands (23% of the agricultural area). This was the most widespread and abrupt land use change (LUC) in the 20th century in the northern hemisphere. The withdrawal of land area from cultivation led to several benefits including carbon (C) sequestration. Here, we provide a geographically complete and spatially detailed analysis of C sequestered in these abandoned lands. The average C accumulation rate in the upper 20 cm of mineral soil was 0.96 ± 0.08 Mg C ha-1 yr-1 for the first 20 years after abandonment and 0.19 ± 0.10 Mg C ha-1yr-1 during the next 30 years of post-agrogenic evolution and natural vegetation establishment. The amount of C sequestered over the period 1990-2009 accounts to 42.6 ± 3.8 Tg C per year. This C sequestration rate is equivalent to ~10% of the annual C sink in all Russian forests. Furthermore, it compensates all fire and post-fire CO2 emissions in Russia and covers about 4% of the global CO2 release due to deforestation and other land use changes. Our assessment shows a significant mitigation of increasing atmospheric CO2 by prolonged C accumulation in Russian soils caused by collective farming collapse. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/groups/opt_out.
