Climatic impact of carbon sequestration through reforestation

通过重新造林固碳对气候的影响

• 批准号: 1413-2006
• 负责人: Harvey, Danny
• 金额: $ 1.26万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=364978
• 关键词: Climatic; impact; carbon; sequestration; through

The Kyoto Protocol allows for emissions of CO2 from fossil fuel use to be offset through the creation of carbon sinks through reforestation. This is allowed because emission followed by prompt absorption of CO2, or no emission and absorption, have identical effects on atmospheric CO2. However, the climatic impacts are not the same because of alterations in the surface properties (namely, the surface albedo or reflectivity) through reforestation. In particular, many C-sink activities likely have a direct warming effect on climate, while removing CO2 from the atmosphere. The impact on CO2 of creating a C sink decreases over time due to interactions with other parts of the carbon cycle, while the radiative effect through alterations in the surface  reflectivity due to reforestation persist as long as the reforestation persists. Canadian policy analysis to date has focused on possible reforestation in Canada and in China (for which Canada might participate and receive some credit). The net climatic impact of reforestation in Canada and in China on climate has not been rigorously assessed, although the potential C sink that could be created has been assessed. The purpose of the proposed research is to provide an assessment of net effects and how they would change over time. The proposed research will consist of (i) adding the capability of radiative transfer calculation to a geographically-specific vegetation/C-storage model that has been used in Canada and in China to assess the potential for C sequestration; (ii) to add an atmosphere column with radiative transfer calculations over top of the vegetation model; (iii) to couple a geographically-distributed implementation of the above models to simple climate and carbon-cycle models so as to assess the interactions of C sequestration with other parts of the carbon cycle; and (iv) to use a state-of-the-art atmospheric general circulation model to assess indirect radiative effects of reforestation through changes in clouds.

《京都议定书》允许通过重新造林创造碳汇来抵消化石燃料使用产生的二氧化碳排放。这是允许的，因为排放后立即吸收二氧化碳，或者不排放和吸收，对大气二氧化碳具有相同的影响。然而，由于重新造林导致地表特性（即地表反照率或反射率）发生变化，气候影响并不相同。特别是，许多碳汇活动可能对气候产生直接变暖效应，同时清除大气中的二氧化碳。由于与碳循环其他部分的相互作用，创建碳汇对二氧化碳的影响会随着时间的推移而减少，而只要重新造林持续，重新造林导致的表面反射率变化所产生的辐射效应就会持续存在。迄今为止，加拿大的政策分析主要集中在加拿大和中国可能的重新造林（加拿大可能参与其中并获得一些信用）。尽管已经评估了可能产生的潜在碳汇，但加拿大和中国重新造林对气候的净气候影响尚未经过严格评估。拟议研究的目的是评估净效应及其随时间的变化。拟议的研究将包括（i）将辐射传输计算能力添加到特定地理植被/碳储存模型中，该模型已在加拿大和中国使用，以评估碳封存的潜力； (ii) 在植被模型之上添加一个带有辐射传输计算的大气柱； (iii) 将上述模型的地理分布实施与简单的气候和碳循环模型结合起来，以评估碳固存与碳循环其他部分的相互作用； (iv) 使用最先进的大气环流模型来评估重新造林通过云层变化产生的间接辐射影响。