Role of terrestrial ecosystems in determining CO2 stabilization and recovery behaviour
Role of terrestrial ecosystems in determining CO2 stabilization and recovery behaviour
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DOI：
10.1111/j.1600-0889.2010.00490.x
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发表时间：
2010-11-01
影响因子：
2.3
通讯作者：
Lowe, Jason
中科院分区：
文献类型：
--
作者：
Jones, Chris;Liddicoat, Spencer;Lowe, Jason
陆地生态系统对气候很敏感，也可以通过生物物理和地球化学反馈影响气候。生态系统的自然碳吸收将控制未来的二氧化碳和气候演变，但生态系统本身可能会导致长期变化。在这里，我们使用一个耦合的气候-碳循环GCM与动态植被调查这些反馈在几个理想化的情况下的政策相关性。我们的研究结果表明，在海洋和陆地上的自然碳循环控制大气CO2的恢复后，在21世纪的三个行动点的减排。最初的回收率相似，但原因不同。海洋的碳吸收超过陆地的吸收，二氧化碳水平升高导致海洋吸收增加，而在陆地上，二氧化碳水平升高导致气候变化加剧，导致碳储存减少。陆地生态系统存在着长期的变化，这些变化在区域上有所不同，并在陆地碳储存缓慢接近新的稳定状态时产生复杂的动态响应。无论是稳定还是CO2恢复，都不能使生态系统恢复到其初始状态，生态系统在减排后的几十年甚至几个世纪内继续作出反应。在界定危险的气候变化和确定避免气候变化的排放途径时，必须考虑到这些长期承诺的变化以及已实现的短暂变化。
Terrestrial ecosystems are sensitive to climate and can also influence it through both biophysical and biogeochemical feedbacks. Natural carbon uptake by ecosystems will control future evolution of CO2 and climate, but the ecosystems themselves may be committed to long-term changes. Here we use a coupled climate-carbon cycle GCM with dynamic vegetation to investigate the policy-relevance of these feedbacks in several idealized scenarios. Our results show that the natural carbon cycle in the ocean and on land controls the recovery of atmospheric CO2 following emissions reductions at three action points during the 21st century. Initial rates of recovery are similar but for different reasons. Ocean carbon uptake exceeds terrestrial uptake, with higher CO2 levels leading to increased ocean uptake whereas on land greater climate change at higher CO2 leads to decreased carbon storage. There are long-term committed changes to terrestrial ecosystems which vary in sign regionally and create a complex dynamic response of terrestrial carbon storage as it slowly approaches a new steady state. Neither stabilization nor CO2 recovery allows ecosystems to recover back to their initial state and the ecosystems continue to respond for decades or even centuries following emissions reductions. These long-term committed changes, in addition to realized, transient changes, must be considered when defining dangerous climate change and identifying emission-pathways to avoid it.