Climate Sensitivity during and between Interglacials (ClimSens)

气候敏感性是辐射强迫变化(例如，大气二氧化碳浓度加倍)后的温度反应。这一参数的值目前还不为人所知，这限制了对未来(21世纪及以后)气候预测的准确性。Clim-Sens项目致力于通过(1)采用长温度和强迫时间序列和(2)实施最先进的统计估计方法来提高气候敏感性估计的准确性。时间序列来自气候模型、冰芯和海洋气候档案；它们覆盖了过去80万年。估计工具包括变量中误差回归和自举重新抽样方法相结合，以确定实际的精度；一个创新的方法步骤是明确考虑了时间尺度的不确定性。与时间序列相适应的回归模型导致新的敏感性估计可能具有更高的精度。CLIMSENS进一步研究了过去间冰期之间的敏感性是如何变化的，以洞察古气候反馈过程的规模。预计结果将有助于加强我们对当前间冰期到21世纪及以后的未来气候演变的了解。

Climate sensitivity is the temperature response following a change in radiative forcing (e.g., doubling of atmospheric carbon dioxide concentration). The value of this parameter is currently not well known, which limits the accuracy of projections of climate in the future (21st century and beyond). The Clim-Sens project is devoted to increasing the accuracy of climate sensitivity estimation by means of (1) employing long temperature and forcing time series and (2) implementing a state-of-the-art statistical estimation method. The time series come from climate models, ice cores and marine climate archives; they cover the past 800 thousand years. The estimation tool consists in errors-in-variables regression combined with a bootstrap resampling approach for a realistic accuracy determination; an innovative methodical step is that timescale uncertainties are explicitly taken into account. The regression model fitted to the time series leads to new sensitivity estimates of likely higher accuracy. ClimSens further studies how the sensitivity varied between past interglacials to obtain insight into the size of paleoclimate feedback processes. Results are expected to be relevant for enhancing our knowledge about the future climate evolution of the present interglacial through the 21st century and beyond.