许多国家正面临加剧的城市热岛（UHI）效应与空气污染的复合风险。尽管严格的气溶胶排放管控已改善背景空气质量，但其对UHI的影响仍缺乏深入研究。本研究利用大样本全球气候模拟表明，背景气溶胶减排在湿润气候区会增强暖季地表UHI，而在干旱地区则削弱该效应。气溶胶减少导致背景向下太阳辐射增加，进而使城市与乡村地表均升温。

Many countries face compounded risks from intensified urban heat islands (UHI) and air pollution. Although stringent aerosol emission controls have improved background air quality, their effects on UHI remain underexplored. Here, using large-ensemble global climate simulations, we show that background aerosol mitigations amplify warm-season surface UHI in humid climates but weaken it in arid regions. Aerosol reductions increase background downward solar radiation and warm both urban and rural surfaces.