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Analysis of long-term ClimAte Change In Australia (ACACIA)

澳大利亚长期气候变化分析 (ACACIA)

基本信息

批准号：
NE/E006183/1
负责人：
Sandy Harrison
金额：
$ 39.19万
依托单位：
University of Bristol
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2007
资助国家：
英国
起止时间：
2007 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FE006183%2F1
关键词：
Analysis long term ClimAte Change

项目摘要

Summary The aim of this project is to investigate the complex interactions between climate, vegetation changes, natural wildfires and human activities, in particular, deliberate fire-setting, over the past 70,000 years in Australia. This period encompasses the initial human colonisation (ca 55,000-45,000 years ago) and subsequent human dispersal across the continent. This colonization is set against the background of large-scale changes in regional climates and environmental conditions, specifically changes in the Australian monsoon which resulted in a significant expansion of the extent of monsoon-fed inland lakes and moisture-demanding vegetation in the mid-continent between ca 65,000 and 45,000 years ago and the subsequent aridification of the continent. Known changes in the external factors affecting regional climates, in particular changes in insolation, atmospheric composition and changes in the extent of polar ice sheets, during the past 70,000 years would have had a significant impact on the Australian monsoon. These changes in climate would in turn have led to changes in the vegetation cover -- changes that in turn influence water- and energy-exchange between the land and the atmosphere, and thus produce feedbacks on the climate system. However, the deliberate or accidental setting of fire by human colonists also affects the vegetation cover and it has been claimed that such activities are also implicated in the Late Quaternary aridification of Australia and the development of fire-adapted vegetation there. We will investigate the relative importance of changes in externally-forced climate changes and human activities in the history of Australian climates and vegetation through a series of experiments using a fast ocean-atmosphere general circulation model. In the first set of experiments, we will examine the response of Australian regional climates to changes in external climate forcing at times in the past 70,000 years corresponding to times when the differences in summer insolation from today were at a maximum or minimum. We will use a coupled vegetation-fire model to examine the effect of the simulated changes in climate on natural vegetation and wildfires. Finally, we will develop plausible scenarios of the extent of human-set fires, based on archaeological evidence for population distribution, density and cultural practices, and use the coupled vegetation-fire model to investigate the impact of human activities on the vegetation and the likely impact of human-induced changes on the climate. Exploring the relative importance of externally-forced climate changes and human activities on regional climate changes and the development of the fire-adapted vegetation characteristic of Australia today will provide a basis for predicting how these relationships will change in the future, and will therefore contribute to the development of improved risk analysis and environmental management tools for a fire-prone continent.

该项目的目的是调查澳大利亚过去7万年来气候、植被变化、自然野火和人类活动，特别是故意纵火之间的复杂相互作用。这一时期包括最初的人类殖民（约55，000 - 45，000年前）和随后的人类分散在整个大陆。这种殖民化是在区域气候和环境条件发生大规模变化的背景下进行的，特别是澳大利亚季风的变化，导致大约65，000年至45，000年前中部大陆的季风内陆湖泊和水分需求植被的范围显着扩大，以及随后的大陆干旱化。在过去7万年中，影响区域气候的外部因素的已知变化，特别是日照、大气成分的变化和极地冰盖范围的变化，对澳大利亚季风产生了重大影响。这些气候变化又会导致植被覆盖的变化，而植被覆盖的变化又会影响土地与大气之间的水和能量交换，从而对气候系统产生反馈。然而，人类殖民者故意或意外的纵火也影响了植被覆盖，有人声称，这些活动也与澳大利亚晚第四纪干旱化和适应火灾的植被的发展有关。我们将通过一系列使用快速海洋-大气环流模型的实验，研究澳大利亚气候和植被历史上外部强迫气候变化和人类活动变化的相对重要性。在第一组实验中，我们将研究澳大利亚区域气候对外部气候强迫变化的响应，在过去的7万年中，对应于夏季日射量与今天的差异达到最大或最小的时候。我们将使用耦合植被火灾模型来研究模拟气候变化对自然植被和野火的影响。最后，我们将根据人口分布，密度和文化习俗的考古证据，开发人类纵火程度的合理情景，并使用耦合植被火灾模型来调查人类活动对植被的影响以及人类活动对气候的可能影响。探索外部强迫的气候变化和人类活动对区域气候变化的相对重要性，以及澳大利亚今天适应火灾的植被特征的发展，将为预测这些关系在未来将如何变化提供基础，因此将有助于改进风险分析和环境管理工具的发展。