The Parties to the UNFCCC and Paris Agreement agreed to act "on the basis of equity" to protect the climate system. Equitable effort-sharing is an irreducibly normative matter, yet some influential studies have sought to create quantitative indicators of equitable effort that claim to be value-neutral (despite evident biases). Many of these studies fail to clarify the ethical principles underlying their indicators, some mislabel approaches which favour wealthy nations as 'equity approaches', and some combine contradictory indicators into composites we call 'derivative benchmarks'. This Perspective reviews influential climate effort sharing assessments and presents guidelines for developing and adjudicating policyrelevant (but not ethically neutral) equity research.

Many U.S. states have taken significant action on climate change in recent years, demonstrating their commitment despite federal policy gridlock and rollbacks. Yet, there is still much we do not know about the agents, discourses, and strategies of those seeking to delay or obstruct state-level climate action. We first ask, what are the obstacles to strong and effective climate policy within U.S. states? We review the political structures and interest groups that slow action, and we examine emerging tensions between climate justice and the technocratic and/or market-oriented approaches traditionally taken by many mainstream environmental groups. Second, what are potential solutions for overcoming these obstacles? We suggest strategies for overcoming opposition to climate action that may advance more effective and inclusive state policy, focusing on political strategies, media framing, collaboration, and leveraging the efforts of ambitious local governments.

This paper updates the analysis of funding of the Climate Change Countermovement from 2003 -2010 to 2003 -2018, doubling the time period of the previous analysis. Funding for the organizations in the CCCM has continually increased at a rate of 3.4% throughout the time period. The source of the vast majority (74%) of this funding cannot be identi ed. Where funding can be identi ed, it is dominated by contributions from a few large conservative philanthropies.