Выявлена новая угроза — таяние вечной мерзлоты на дне термокарстовых озер на Аляске и в Сибири.
'Abrupt thaw' of permafrost beneath lakes could significantly affect climate change models
| | Отрывок (на английском) |
| | Emissions from thermokarst lakes aren't currently factored into global climate models because their small size makes individual lakes difficult to include. However, the study's authors show that these lakes are hotspots of permafrost carbon release. They argue that not including them in global climate models overlooks their feedback effect, which occurs when the release of greenhouse gases from permafrost increases warming. That feedback is significant because methane is about 30 times more potent than carbon dioxide as a heat-trapping gas.
Existing models currently attribute about 20 percent of the permafrost carbon feedback this century to methane, with the rest due to carbon dioxide from terrestrial soils. By including thermokarst lakes, methane becomes the dominant driver, responsible for 70 to 80 percent of permafrost carbon-caused warming this century. Adding thermokarst methane to the models makes the feedback's effect similar to that of land-use change, which is the second-largest source of manmade warming.
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Если вкратце, существующие модели изменения климата не в полной мере учитывают возможные выбросы метана при оттаивании дна термокарстовых озер, которые могут внести гораздо больший вклад в глобальное потепление, чем предполагалось ранее.