近日，美国得克萨斯农工大学Xiaohong Liu团队报道了野火中深棕色碳的强烈全球辐射效应。2026年5月12日出版的《自然—地球科学》杂志发表了这项成果。

野火会排放大量棕色碳——这是一类吸光性有机气溶胶，其气候效应目前仍缺乏有效约束。棕色碳呈现出宽泛的吸光能力谱，从近紫外波段弱吸光的发色团，到吸光能力强且延伸至可见光波段的物质——然而，其光学特性、全球分布及辐射影响在很大程度上仍不明确。

研究组通过整合分析飞机观测、地面监测和卫星遥感数据，评估了深棕色碳的全球普遍性及其光学特征。结果表明，这种强吸光性气溶胶在世界各地的野火烟羽中广泛存在。实测深棕色碳在500 nm波长的质量吸收效率为0.5至1.5 m2 g-1，其吸光能力经常与黑碳相当，甚至超过黑碳。

将这些受观测约束的光学特性纳入全球气溶胶-气候模型后，研究组估算出野火源棕色碳的直接辐射效应为+0.097 W m-2（范围+0.050至+0.276 W m-2），其上限值超过了黑碳的贡献，并延伸至包括北极的中高纬度地区。这些结果将深棕色碳定位为野火辐射强迫中一个关键但尚未被充分认识的贡献因素，强调了在气候评估中需考虑其显著的增温影响。

附：英文原文

Title: Strong global radiative effects from wildfire dark brown carbon

Author: Xu, Lulu, Lin, Guangxing, Wu, Chenglai, Chen, Xi, Wang, Hao, Chen, Cheng, Chakrabarty, Rajan K., Gao, Meng, Vakkari, Ville, van Zyl, Pieter G., Liu, Xiaohong

Issue&Volume: 2026-05-12

Abstract: Wildfires emit large quantities of brown carbon, a class of light-absorbing organic aerosols whose climate effects remain poorly constrained. Brown carbon displays a broad spectrum of absorptivity, ranging from weakly absorbing chromophores in the near-ultraviolet to strongly absorbing species that extend into the visible spectrum—yet its optical properties, global distribution and radiative influence remain largely uncertain. Here we assess the global prevalence and optical characteristics of dark brown carbon through an integrated analysis of aircraft measurements, ground-based observations and satellite retrievals. We show that this strongly absorbing aerosol is widespread in wildfire plumes around the world. Measured dark brown carbon mass absorption efficiencies range from 0.5 to 1.5m2 g1 at 500nm, with absorption frequently comparable to—or even exceeding—that of black carbon. When these observationally constrained optical properties are incorporated into a global aerosol–climate model, we estimate a direct radiative effect of +0.097Wm2 (spanning +0.050 to +0.276Wm2) attributable to wildfire-derived brown carbon, with the upper bound surpassing black carbon’s contribution and extending into mid- and high-latitude regions, including the Arctic. These results position dark brown carbon as a critical yet underrecognized contributor to wildfire radiative forcing, highlighting the need to account for its substantial warming influence in climate assessments.

DOI: 10.1038/s41561-026-01972-9

Source: https://www.nature.com/articles/s41561-026-01972-9