Observational constraints on climate projections

气候预测的观测限制

基本信息

批准号：
402301-2011
负责人：
Gillett, Nathan
金额：
$ 1.52万
依托单位：
University of Victoria
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2014
资助国家：
加拿大
起止时间：
2014-01-01 至 2015-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=550865
关键词：
Observational constraints climate projections

项目摘要

The objective of the proposed research is to use observations of climate change over the past century to improve climate model predictions of future climate change. Climate models are the best available tools for predicting future climate change, providing key information necessary to inform decisions on reducing greenhouse gas emissions, and adaptation to future climate change. However, due to the many complexities of the climate system and uncertainties in its properties, climate model projections of future change in many aspects of the climate differ strongly between models. For example the last United Nations IPCC assessment report concluded that, even given a specific trajectory of 21st century emissions, 21st century global warming could be anywhere from 2.4°C to 6.4°C. While the impacts on society and the environment from a warming of 2.4°C might be manageable, the impacts of a warming of 6.4°C would likely be very severe. Thus it is important to try to reduce these uncertainties, if climate predictions are to be more useful to policymakers and society at large. The proposed research focuses on using observations of past climate change to improve our predictions of future climate change. A large number of climate model simulations are currently being carried out around the world in preparation for the next report of the UN IPCC report. By analysing simulated climate change over both the historical period (1850-2010) and the future, it should be possible to identify robust relationships between simulated past climate change and simulated future climate change. To take a simple example, we might find that models which warm more in the past tend also to warm more in the future. We can then use observations of past climate change, either to rule out some models as being either too sensitive to greenhouse gas increases or not sensitive enough, or we can rescale model projections so that the match to observations is improved. Such research carried out to date has had limited success in constraining future projections. But the availability of new simulations with better models, many finishing in 2010, presents a promising new opportunity to improve our climate projections in this way.

拟议研究的目的是利用过去一个世纪对气候变化的观测来改进气候模型对未来气候变化的预测。气候模型是预测未来气候变化的最佳可用工具，为减少温室气体排放决策提供必要的关键信息。然而，由于气候系统的复杂性及其特性的不确定性，气候模型对未来气候变化的许多方面的预测之间存在很大差异。 IPCC评估报告的结论是，即使给定特定的轨迹根据 21 世纪的排放量，21 世纪的全球变暖可能在 2.4°C 至 6.4°C 之间，虽然升温 2.4°C 对社会和环境的影响可能是可控的，但升温 6.4°C 的影响将是可控的。因此，如果气候预测要对政策制定者和整个社会更有用，那么尝试减少这些不确定性就很重要。拟议的研究重点是利用对过去气候变化的观测来改善我们的情况。通过分析历史时期（1850-2010年）和2010年的模拟气候变化，目前世界各地正在开展大量气候模型模拟，为联合国IPCC报告的下一份报告做准备。未来，应该有可能确定模拟的过去气候变化和模拟的未来气候变化之间的稳健关系，举一个简单的例子，我们可能会发现过去变暖的模型未来也会变暖。使用观察结果过去的气候变化，要么排除某些模型对温室气体增加过于敏感或不够敏感，要么我们可以重新调整模型预测，以便改善与观测的匹配，迄今为止进行的此类研究取得的成功有限。但是，使用更好的模型进行的新模拟（其中许多已于 2010 年完成）的出现，为我们以这种方式改进气候预测提供了一个充满希望的新机会。