Planting trees has become a popular solution for climate change mitigation, owing to the ability of trees to accumulate carbon in biomass and thereby reduce anthropogenic atmospheric CO₂ enrichment. As conditions for tree growth expand with global warming, tree-planting projects have been introduced in regions of the highest northern latitudes. However, several lines of evidence suggest that high-latitude tree planting is counterproductive to climate change mitigation. In northern boreal and Arctic regions, tree planting results in net warming due to increased surface darkness (decreased albedo), which counteracts potential mitigation effects from carbon storage in areas where biomass is limited and of low resilience. Furthermore, tree planting disturbs pools of soil carbon, which store most of the carbon in cold ecosystems, and has negative effects on native Arctic biota and livelihoods. Despite the immediate economic prospects that northern tree planting may represent, this approach does not constitute a valid climate-warming-mitigation strategy in either the Arctic or most of the boreal forest region. This has been known for decades, but as policies that incentivize tree planting are increasingly adopted across the high-latitude region, we warn against a narrow focus on biomass carbon storage. Instead, we call for a systems-oriented consideration of climate solutions that are rooted in an understanding of the whole suite of relevant Earth system processes that affect the radiative balance. This is crucial to avoid the implementation of ineffective or even counterproductive climate-warming mitigation strategies in the Arctic and boreal regions.

植树已成为缓解气候变化的流行解决方案，因为树木能够在生物质中积累碳，从而减少人为大气中 CO₂ 的富集。随着全球变暖，树木生长条件扩大，北方最高纬度地区开始开展植树项目。然而，几条证据表明，高纬度植树对缓解气候变化适得其反。在北部北方和北极地区，由于表面黑暗增加（反照率降低），植树导致净变暖，这抵消了生物量有限且恢复力低的地区碳储存的潜在缓解作用。此外，植树会扰乱土壤碳池，土壤碳池将大部分碳储存在寒冷的生态系统中，并对北极原生生物群和生计产生负面影响。尽管北方植树可能代表着直接的经济前景，但这种方法在北极或大部分北方森林地区并不构成有效的气候变暖缓解战略。几十年来，人们都知道这一点，但随着鼓励植树造林的政策在高纬度地区越来越多地采用，我们警告不要狭隘地关注生物质碳储存。相反，我们呼吁以系统为导向考虑气候解决方案，这些解决方案植根于对影响辐射平衡的一整套相关地球系统过程的理解。这对于避免在北极和北方地区实施无效甚至适得其反的气候变暖缓解策略至关重要。