Lightning strongly influences atmospheric chemistry^1,2,3, and impacts the frequency of natural wildfires⁴. Most previous studies project an increase in global lightning with climate change over the coming century^1,5,6,7, but these typically use parameterizations of lightning that neglect cloud ice fluxes, a component generally considered to be fundamental to thunderstorm charging⁸. As such, the response of lightning to climate change is uncertain. Here, we compare lightning projections for 2100 using two parameterizations: the widely used cloud-top height (CTH) approach⁹, and a new upward cloud ice flux (IFLUX) approach¹⁰ that overcomes previous limitations. In contrast to the previously reported global increase in lightning based on CTH, we find a 15% decrease in total lightning flash rate with IFLUX in 2100 under a strong global warming scenario. Differences are largest in the tropics, where most lightning occurs, with implications for the estimation of future changes in tropospheric ozone and methane, as well as differences in their radiative forcings. These results suggest that lightning schemes more closely related to cloud ice and microphysical processes are needed to robustly estimate future changes in lightning and atmospheric composition.

雷电强烈影响大气化学^1,2,3，并影响自然野火的发生频率⁴。大多数以前的研究预测，在未来的一个世纪^{1、5、6、7中}，全球闪电会随着气候变化而^增加，但是这些研究通常使用忽略云冰通量的闪电参数化，而云冰通量通常被认为是雷暴充电的基础⁸。因此，闪电对气候变化的反应是不确定的。在这里，我们使用两个参数比较2100年的闪电投影：广泛使用的云顶高度（CTH）方法⁹和新的向上云冰通量（IFLUX）方法¹⁰克服了以前的局限性。与先前报道的基于CTH的全球闪电增加相反，我们发现在强烈的全球变暖情况下，IFLUX在2100年的总闪电闪烁率降低了15％。在发生闪电最多的热带地区，差异最大，这对估计对流层臭氧和甲烷的未来变化以及它们的辐射强迫有影响。这些结果表明，需要与云冰和微物理过程更紧密相关的雷电方案，才能有力地估计雷电和大气成分的未来变化。