With climate change litigation proliferating throughout the world, a substantial body of case law is emerging. As part of a project of the IUCN World Commission on Environmental Law's Climate Change Specialist Group, this Article, a version of which will be included in a “Judicial Handbook on Climate Litigation,” explains the public trust doctrine’s influence on climate change litigation internationally. We select what we view as judicial “best practices” as a kind of restatement of international atmospheric trust law in 2022. International atmospheric trust law is at the forefront of many best practices, as state and federal courts in the United States have fettered the public trust doctrine’s development by erecting procedural hurdles like standing and political question doctrines. On the other hand, international courts do not suffer from these procedural limitations, allowing them to reach the merits of public trust claims in the context of climate change. This Article explains these developments in an effort to synthesize the rapidly developing case law.