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Thu, 07/29/2021 - 18:18
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Scientists offer method to assess carbon emissions in Siberian wildfires

YAKUTSK, July 28. /TASS/. The Sukachev Institute of Forest (the Krasnoyarsk scientific center of the Russian Academy of Sciences’ Siberian Branch) offers new methods to assess emissions of carbon and greenhouse gases in wildfires in Siberia, including in the Arctic zone, the institute’s representative Evgeny Ponomarev told TASS. The assessment of direct emissions of carbon dioxide and other greenhouse gases into the atmosphere in wildfires is used to estimate carbon’s balance in forests. "We have developed a new approach to estimating emissions of carbon-containing gases in wildfires in Siberia, including in the Arctic zone, in terms of pure carbon. This is a refined technique that considers the emission of gases not only on the basis of fire areas - it also takes into account intensity of each fire, recorded from the satellite. As a result, we receive a more reliable estimation of annual emissions, caused by wildfires," the expert said. The scientist noted that the new method cuts the level of uncertainty, which existed in earlier assessing methods, by about 15-20%. "According to our estimates, in Siberia, every year in wildfires about 100 teragrams (100 million tons - TASS) per year are released into the atmosphere. At the same time, our foreign counterparts, analyzing emissions in Siberian wildfires, usually give inflated estimates - between 300 and 500 teragrams. Apparently, it is not sufficient to know only the area of fires, it is necessary to use a differential approach to analyze burning intensity in different sites," he continued. He noted that the obtained estimate is an average value typical for "moderate" fire-hazardous seasons. "However, in case of extreme burning, like, for example, in 2020, this indicator may jump to 250 teragrams or higher. This is exactly how much was emitted into the atmosphere during the forest fires in the 2020 season. In the seasons of low burning, fire emissions amount to 20-40 million tons," he said. The Krasnoyarsk scientists together with experts from the Siberian Federal University and George Mason University (USA, VA) wrote an article containing these estimates and trends of fire emissions. The article was published in the well-known Atmosphere scientific journal. Fires will happen more often The scientist stressed it would be necessary during the coming years to get ready for an increase in the scale of forest fires in remote areas, where it is difficult or impossible to control and extinguish wildfires at early stages. "We can see evident climatic changes: increasing summer temperatures, long dry periods, and a redistribution of precipitation. All these changes may lead to changes in fire regimes, to burning of forests. We have been using satellite monitoring to watch wildfires for recent 25 years, plus the apparent climate changes, thus the forecast is as follows: we need to be prepared for the situation, where the number of fires will only grow," he said. Fires tend to occur in areas with no population, roads, runways, or special forest protection forces. "Unfortunately, such territories are numerous. Thus, we can forecast that fires will spread over large areas. The long-term analysis shows that from 75 to 90% or more of all the territories hit by wildfires belong to the zone where any control of fires is impossible. Those are satellite monitoring zones. In those zones fires may continue for quite a time, and they may be stopped only in case of changing weather conditions or precipitation," the scientist said. "In Siberia and in the Far East, especially in the northern areas, wildfires are likely to happen more often and to be bigger. In particular, we are talking about Evenkia, the northern regions of Yakutia, Chukotka, and the north of Kamchatka. We should also mind the regions like the Angara region, the Baikal region, where the situation with wildfires is also often very dramatic," he continued. The scientist pointed to existing fire forecast scenarios from low to extreme. The calculation of fire probabilities and repetition periods are based on long-term observations, he said. At the same time, according to modern research, the share of fires caused by thunderstorms will increase in the climate warming period. The proportion will be as follows: the warming by 1 degree will entail a 10-15% increase in the number of lightning, which is a potential sources of fires in forests, the expert told TASS. "In low populated areas, with few roads, the natural causes of fires are - lightning, dry thunderstorms, lightning without rain. It is impossible to say blindly who causes these fires - humans or the nature. Quite often, when observing satellite images to see how fires spread across a territory, we realize that humans cannot be involved in all the fires. Specialists say, up to 70% of fires, especially in the northern regions of Siberia, may be caused by lightning," he said. Positive function of fires Forest fires in Siberia have a positive side: they can contribute to the renewal of coniferous stands, although more often through they cause changes of breeds and renewal of berry plants and grass cover, the scientist said. "Fire is a common factor for the nature, which has always existed. The nature thus knows how to regulate itself, and how to recover from such phenomena. The positive function of fires is that a fire cuts the level of natural fire danger. A large layer of needles, fallen trees gets accumulated in forests. If this layer remains for a long time, an extreme fire will be highly probable," he said. Fires also help to regulate the age composition of trees. After a fire, with successful restoration, trees of different ages are formed, which is good for the ecosystem. With trees of different ages, the ecosystem will function for a long time. He added that experiments on controlled burning were carried out in the US and Canada, and in Siberia in order to reduce the natural fire danger. "This method is not used in Russia, since the regulatory and legal bases do not allow such forest-management forms. As an experiment, this experience was quite successful," the scientist said. The scientist gave an example of the fire in the US Yellowstone Nature Reserve in 1988. "The territory was perfectly protected, there were no fires there for almost 100 years, and at one instant all the accumulated burning stuff in the forests caught fire, and the park burned to the ground," he noted. According to the expert, in addition to increasing funding for forest protection, upgrade of the system to detect and extinguish fires in forests, Russia must increase the level of ecological culture in the population, and responsible attitudes to the nature. Read more