In 4°C, Ruhl and Craig effectively argue that governance measures, particularly adaptation planning, will fall short if institutions fail to embrace the real possibility that the planet will blow well past 2° Celsius (°C) above pre-industrial temperatures. Further, they argue that 4°C is a better target for adaptation planning because this metric better captures the future risk the nation faces. Ruhl and Craig are keenly aware that serious talk of a possible 4°C future will almost certainly trigger accusations of “doomism” from various critics.

In 4°C, Ruhl and Craig acknowledge that the Earth’s climate is changing at an increasingly rapid rate, outside the range to which society has adapted in the past. Realistically, achieving the goal set in the 2015 Paris Agreement of limiting global warming to 1.5°C will be almost unattainable without drastic actions to reduce greenhouse gas emissions.

Accelerating ice loss and expanding wildfire zones are potential markers of what are known as tipping points—thresholds along a nonlinear pattern of system change that accelerate the pace of change. Scientists are concerned that our global climate system is dangerously close to passing these points. This trend has significant implications for governance and law. Climate change disruptions will extend beyond biophysical systems to social systems, including systems of governance.

This Article, adapted from the Climate Science and Law for Judges Curriculum, examines the status and viability of judicial remedies in climate change litigation. It focuses on climate cases that are seeking science-based remedies specifically related to climate mitigation (actions to reduce greenhouse gas emissions or draw down atmospheric carbon) and climate-change adaptation (actions to reduce the negative impacts of climate disruption on human and natural communities).

In June 2022, in West Virginia v. Environmental Protection Agency, the U.S. Supreme Court announced that on “major questions” the U.S. Congress must legislate with far more clarity and specificity than previously demanded. The Court held the U.S. Environmental Protection Agency (EPA) may regulate power plant carbon emissions in traditional ways, but the novel approach taken in the Clean Power Plan required clearer authorization than Congress had provided. Six weeks later, Congress enacted the Inflation Reduction Act (IRA).