 Abstract larch, a widely distributed tree in boreal Eurasia, is experiencing rapid warming across much of its distribution. Previous studies have shown that warmer temperatures can negatively affect the growth of this species, but these studies were limited in their ability to accurately capture the full extent of the effects of warming. To address this issue, researchers developed a new method for creating physiologically relevant temperature data that better captures the effects of warming on growth. This method indicated that warming has already caused negative growth responses in many areas of boreal Eurasia, with these responses expected to spread further north and higher in elevation over the coming decades. These findings suggest that the risks associated with warming to this region may be greater than previously thought. This article was authored by Wen Qing Li, Ruben Di Manzanado, Yuan Jiang, and others.