In their comment on our paper (Caesar et al 2020 Environ. Res. Lett. 15 024003), Chen and Tung (hereafter C&T) argue that our analysis, showing that over the last decades Atlantic meridional overturning circulation (AMOC) strength and global mean surface temperature (GMST) were positively correlated, is incorrect. Their claim is mainly based on two arguments, neither of which is justified: first, C&T claim that our analysis is based on ‘established evidence’ that was only true for preindustrial conditions—this is not the case. Using data from the modern period (1947–2012), we show that the established understanding (i.e. deep-water formation in the North Atlantic cools the deep ocean and warms the surface) is correct, but our analysis is not based on this fact. Secondly, C&T claim that our results are based on a statistical analysis of only one cycle of data which was furthermore incorrectly detrended. This, too, is not true. Our conclusion that a weaker AMOC delays the current surface warming rather than enhances it, is based on several independent lines of evidence. The data we show to support this covers more than one cycle and the detrending (which was performed to avoid spurious correlations due to a common trend) does not affect our conclusion: the correlation between AMOC strength and GMST is positive. We do not claim that this is strong evidence that the two time series are in phase, but rather that this means that the two time series are not anti-correlated.

在他们对我们论文的评论中（Caesar et al 2020 Environ. Res. Lett. 15024003)、Chen 和 Tung（以下简称 C&T）认为，我们的分析表明，过去几十年大西洋经向翻转环流 (AMOC) 强度与全球平均地表温度 (GMST) 呈正相关，这是不正确的。他们的主张主要基于两个论据，这两个论据都不合理：首先，C&T 声称我们的分析是基于仅适用于前工业条件的“既定证据”——事实并非如此。使用现代时期（1947-2012）的数据，我们表明既定的理解（即北大西洋的深水形成使深海变冷，使海面变暖）是正确的，但我们的分析并非基于这一事实。其次，C&T 声称我们的结果仅基于对一个数据周期的统计分析，而且该数据被错误地去趋势化。这也是不正确的。我们的结论是，较弱的 AMOC 会延迟而不是增强当前的地表变暖，这是基于几个独立的证据。我们显示的支持这一点的数据涵盖了多个周期，并且去趋势（这是为了避免由于共同趋势而产生的虚假相关性）不会影响我们的结论：AMOC 强度和 GMST 之间的相关性是正的。我们并不是说这是两个时间序列同相的有力证据，而是这意味着这两个时间序列不是反相关的。我们显示的支持这一点的数据涵盖了多个周期，并且去趋势（这是为了避免由于共同趋势而产生的虚假相关性）不会影响我们的结论：AMOC 强度和 GMST 之间的相关性是正的。我们并不是说这是两个时间序列同相的有力证据，而是这意味着这两个时间序列不是反相关的。我们显示的支持这一点的数据涵盖了多个周期，并且去趋势（这是为了避免由于共同趋势而产生的虚假相关性）不会影响我们的结论：AMOC 强度和 GMST 之间的相关性是正的。我们并不是说这是两个时间序列同相的有力证据，而是这意味着这两个时间序列不是反相关的。