"access to U.S. foreign and domestic policy papers and gray literature, PolicyFile is updated weekly with abstracts and links to the latest reports, papers, and documents from think tanks, research institutes, and agencies."
The Intergovernmental Panel on Climate Change (IPCC) is a United Nations body where you can access the science related to climate change. It provides climate data, socio-economic and environmental data and includes scenarios with future projections.
Office of Program Policy Analysis and Government Accountability (OPPAGA)
"OPPAGA is a research arm of the Florida Legislature. OPPAGA supports the Florida Legislature by providing data, evaluative research, and objective analyses that assist legislative budget and policy deliberations."
"The Correlates of State Policy Project includes more than seven-hundred variables, with observations across the U.S. 50 states and time (1900 – 2016). These variables represent policy outputs or political, social, or economic factors that may influence policy differences across the states."