Biomass feasibility study

21世纪环境科学面临的主要挑战是提高我们对全球变化（包括气候变化和人类对地球表面和海洋的改变）将如何影响地球系统及其反馈的认识。来自太空的测量对于了解物理、化学、生物和人为过程如何在这个全球综合系统中相互交织至关重要。在构成地球系统的三个领域（大气、海洋和陆地）中，陆地生物圈的现状、动态和演化是最不为人所知和最不确定的。这种不确定性贯穿了从地方到全球的整个范围。我们所知道的是，由于人类对食物和其他资源的需求，陆地表面正在发生大规模和迅速的变化，对气候、生物多样性和可持续性造成严重后果。目前不存在适合碳循环和地球系统模型的网格化生物量信息，也没有生物多样性和森林管理调查所需的全球、一致、准确和经常更新的森林面积、结构和变化制图。这一需求是迫切的，与NERC的优先事项有明确的关系，但现有的地球观测任务或任何其他数据源无法满足这一需求。生物质p波段雷达将为满足这一需求做出独特的重大贡献。它将大大提高我们量化碳循环的陆地组成部分及其与水循环的联系的能力，将为社会和生态系统提供重要的信息，并将有助于填补地球系统耦合模型数据需求方面的一个关键空白。

The primary challenge for the environmental sciences in the 21st century is to improve our knowledge on how global change, including climate change and human modifications of the Earth's surface and oceans, will affect the Earth system and the feedbacks in this system. Measurements from space are crucial to understanding how physical, chemical, biological and anthropogenic processes are intertwined in this global integrated system. Among the three domains (the atmosphere, ocean and land) making up the Earth system, the status, dynamics and evolution of the terrestrial biosphere are the least understood and most uncertain. This uncertainty runs across the whole gamut of scales, from local to global. What we do know is that the land surface is suffering large-scale and rapid changes in response to human demands for food and other resources, with serious consequences for climate, biodiversity and sustainability. Current gridded biomass information suitable for carbon cycle and Earth system models does not exist, nor do we have the global, consistent, accurate and frequently updated mapping of forest area, structure and change needed for biodiversity and forest management investigations. This need is urgent and has explicit relevance to NERC priorities, but is not met by existing Earth Observation missions or any other data source. The BIOMASS P-band radar will provide a unique, major contribution to meeting this need. It will significantly improve our ability to quantify the terrestrial component of the carbon cycle and its links to the water cycle, will provide information of major importance for societies and ecosystems, and will help to fill a crucial gap in the data requirements for coupled models of the Earth System.