A study reevaluates the risks of climate change for terrestrial ecosystems, highlighting the need for targeted conservation strategies. The research combines ecophysiological growth models of 135,153 vascular plant species with plant growth-form data to transform ambient and future climatologies into phytoclimates, which describe the ability of climates to support plant growth forms. By 2070, under RCP 2.6 and RCP 8.5 scenarios, 33-68% of the global land surface is expected to experience significant changes in phytoclimates. Novel phytoclimates are forecast to emerge on 0.3-2.2% of the land surface, while 0.1-1.3% of current phytoclimates are expected to disappear. These changes differ from previous climate change exposure trends, defining new conservation priorities and highlighting the limitations of using untransformed climate indices in ecological risk assessments. The study finds that phytoclimatic zones, which represent areas where the climate supports similar plant types, are shifting significantly by 2070. Under RCP 8.5, large parts of zones supporting cool-temperate and hemiboreal ecosystems will shift polewards, while zone 16 (tundra) will shrink by 72%. Tropical phytoclimatic zones are less likely to change, but some regions may experience strong structural changes in ecosystems. Novel phytoclimates are expected to emerge in southeastern South America and Australia, with increased suitability for certain plant growth forms and reduced suitability for others. Disappearing phytoclimates are also forecast in mesic subtropical climates, with 0.1-1.3% of ambient phytoclimates expected to disappear by 2070. The study emphasizes the need for adaptive management practices to address the profound transformation of the biosphere. It suggests that current approaches to understanding ecological climate change risks trade off prediction certainty with ecological interpretation. The phytoclimatic transformation provides a more accurate assessment of where and how climatic drivers of ecosystem assembly are changing. The study also highlights the importance of considering physiological and ecological responses to climate change, which are often nonlinear and colimited by multiple factors. The findings suggest that climate change will significantly impact ecosystem structure, functioning, and dynamics, necessitating a shift in conservation and management strategies to address these changes.A study reevaluates the risks of climate change for terrestrial ecosystems, highlighting the need for targeted conservation strategies. The research combines ecophysiological growth models of 135,153 vascular plant species with plant growth-form data to transform ambient and future climatologies into phytoclimates, which describe the ability of climates to support plant growth forms. By 2070, under RCP 2.6 and RCP 8.5 scenarios, 33-68% of the global land surface is expected to experience significant changes in phytoclimates. Novel phytoclimates are forecast to emerge on 0.3-2.2% of the land surface, while 0.1-1.3% of current phytoclimates are expected to disappear. These changes differ from previous climate change exposure trends, defining new conservation priorities and highlighting the limitations of using untransformed climate indices in ecological risk assessments. The study finds that phytoclimatic zones, which represent areas where the climate supports similar plant types, are shifting significantly by 2070. Under RCP 8.5, large parts of zones supporting cool-temperate and hemiboreal ecosystems will shift polewards, while zone 16 (tundra) will shrink by 72%. Tropical phytoclimatic zones are less likely to change, but some regions may experience strong structural changes in ecosystems. Novel phytoclimates are expected to emerge in southeastern South America and Australia, with increased suitability for certain plant growth forms and reduced suitability for others. Disappearing phytoclimates are also forecast in mesic subtropical climates, with 0.1-1.3% of ambient phytoclimates expected to disappear by 2070. The study emphasizes the need for adaptive management practices to address the profound transformation of the biosphere. It suggests that current approaches to understanding ecological climate change risks trade off prediction certainty with ecological interpretation. The phytoclimatic transformation provides a more accurate assessment of where and how climatic drivers of ecosystem assembly are changing. The study also highlights the importance of considering physiological and ecological responses to climate change, which are often nonlinear and colimited by multiple factors. The findings suggest that climate change will significantly impact ecosystem structure, functioning, and dynamics, necessitating a shift in conservation and management strategies to address these changes.