Climate Equity Act of 2020 This bill requires the review and analysis of new legislation, regulation, or federal investments that are related to environmental or climate change issues and sets forth related requirements. The analysis must determine the impacts of such legislation, regulation, or investments on frontline communities (e.g., communities that have experienced environmental injustice or are vulnerable to climate injustice). Specifically, the bill establishes a Climate and Environmental Equity Office within the Congressional Budget Office. The former must prepare an analysis for each bill or resolution with an environmental or climate change nexus that is reported by any congressional committee. The analysis must include the bill's impacts on frontline communities. The bill also establishes an Office of Climate and Environmental Justice Accountability within the Office of Management and Budget. Among other things, the former must (1) measure the costs of environmental and climate regulations on frontline communities, (2) review agencies' investments to determine if they have an environmental or climate change nexus and ensure that frontline communities benefit from such investments, and (3) represent the views of frontline communities in the rulemaking process. Each agency must biannually publish a climate and environmental justice accountability agenda. An agency must prepare and publish a climate and environmental justice analysis for a proposed or final rule that may have a significant impact on a substantial number of residents within frontline communities. Further, each agency must ensure that frontline communities have been given an opportunity to participate in the rulemaking process.