Analysis and modelling of climate-land cover interactions with a carbon cycle perspective

长期以来，气候和碳循环之间的相互作用被认为是决定地球气候状态的重要因素。这些复杂的相互作用涉及大气、海洋、海底沉积物、陆地表面和生物群之间的交换，通过设定大气中二氧化碳的浓度，对确定地球的辐射收支至关重要。通过与生物圈的联系，碳循环还对反照率、地表粗糙度和蒸散发等与气候相关的其他参数产生重大影响。所有这些相互作用在气候对人为二氧化碳排放的响应中发挥着重要作用，很明显，面对未来气候变化，社会所需的详细和可靠的预测必须建立在对这些气候-碳循环联系的扎实理解的基础上。此外，这种认识必须纳入用于产生这些预测的全球和区域模式。最近出现的数值耦合全球气候-碳循环模式构成了该领域的重大进展。对这种模式的预测能力至关重要的是它们能够解释植被动态，植被动态通过影响陆地表面和大气之间的质量和能量通量，在广泛的时间和空间尺度上对气候起着重要作用。从长远来看，本研究计划旨在通过应用和发展耦合气候-碳循环模型，提高我们对植被动态与气候相互作用的认识。它的短期目标是：i)通过发展昆虫对中高纬度森林影响的参数化来提高目前模式的预测能力- -这一过程虽然对这些生态系统的碳收支非常重要，但目前在全球模式中是不存在的；ii)通过前所未有的大量数值模拟来量化植被覆盖对气候变化的响应；iii)量化人为引起的植被覆盖变化的气候影响，包括在全球环流模式中生成目前尚不存在的造林的现实表示。

Interactions between climate and the carbon cycle have long been recognized as important in determining the Planet's climate state. These complex interactions involve exchanges between the atmosphere, ocean, bottom sediments, land surface and biota and are fundamental, by setting the atmospheric concentration of CO2, in the determination of the Planet's radiative budget. Through its connection to the biosphere, the carbon cycle also has a significant impact on other parameters relevant to climate such as albedo, surface roughness and evapotranspiration. All these interactions play an important role on the climate response to anthropogenic CO2 emissions, and it is clear that the detailed and reliable predictions required by society in the face of future climate change must be based on a solid understanding of these climate-carbon cycle connections. Moreover, this understanding must be incorporated into the global and regional models being used to generate these predictions. The recent advent of numerical coupled global climate-carbon cycle models constitutes a significant advancement for the field. Crucial to the predictive skills of such models is their ability to account for vegetation dynamics which, by influencing fluxes of mass and energy between the land surface and the atmosphere, play an important role in climate over a broad range of temporal and spatial scales. This research proposal is aimed, in the long-term, at enhancing our understanding of the interaction between vegetation dynamics and climate through the application and development of coupled climate-carbon cycle models. Its short-term goals are: i) To increase the predictive skills of current models through the development of a parameterization for insect impact on mid- to high-latitude forests - a process that, although being of great importance to the carbon budget of these ecosystems, is presently absent from global models; and ii) To quantify, through a unprecedentedly large number of numerical simulations, the response of vegetation cover to climate change and iii) To quantify the climatic effects of human-induced vegetation cover change, including work to generate a, presently inexistent, realistic representation of afforestation in a Global Circulation Model.