Constraints and limits to adaptation are critical to understanding the extent to which human and natural systems can successfully adapt to climate change. We conduct a systematic review of 1,682 academic studies on human adaptation responses to identify patterns in constraints and limits to adaptation for different regions, sectors, hazards, adaptation response types, and actors. Using definitions of constraints and limits provided by the Intergovernmental Panel on Climate Change (IPCC), we find that most literature identifies constraints to adaptation but that there is limited literature focused on limits to adaptation. Central and South America and Small Islands generally report greater constraints and both hard and soft limits to adaptation. Technological, infrastructural, and ecosystem-based adaptation suggest more evidence of constraints and hard limits than other types of responses. Individuals and households face economic and socio-cultural constraints which also inhibit behavioral adaptation responses and may lead to limits. Finance, governance, institutional, and policy constraints are most prevalent globally. These findings provide early signposts for boundaries of human adaptation and are of high relevance for guiding proactive adaptation financing and governance from local to global scales.

适应的约束和限制对于了解人类和自然系统成功适应气候变化的程度至关重要。我们对 1,682 项关于人类适应反应的学术研究进行了系统审查，以确定不同地区、部门、灾害、适应反应类型和参与者的适应限制和限制模式。使用政府间气候变化专门委员会 (IPCC) 提供的约束和限制的定义，我们发现大多数文献确定了适应的限制，但关注适应限制的文献有限。中美洲和南美洲以及小岛屿普遍报告说，适应的制约因素更大，硬限制和软限制也不同。技术、基础设施、和基于生态系统的适应表明比其他类型的响应更多的限制和硬限制的证据。个人和家庭面临经济和社会文化约束，这也会抑制行为适应反应并可能导致限制。金融、治理、制度和政策限制在全球范围内最为普遍。这些发现为人类适应的边界提供了早期路标，并且对于指导从地方到全球范围的主动适应融资和治理具有高度相关性。