From the Document: "Over the past several decades, to varying degrees, the United States has delivered financial and technical assistance for climate change activities in the developing world through a variety of bilateral and multilateral channels with appropriations passed by Congress and implemented by the executive agencies. Climate finance is funded primarily through programs at the Department of State, the Department of the Treasury, and the U.S. Agency for International Development (USAID). Funds for these programs are requested in the President's budget under the International Affairs function (Function 150) and funded through the annual State, Foreign Operations, and Related Programs (SFOPS) appropriation. Many activities are funded at agency subaccount levels, with allocations left to the discretion of the agencies under congressional consultation. Some additional international assistance is funded at other federal agencies (e.g., U.S. Environmental Protection Agency; National Aeronautics and Space Administration; National Science Foundation; Peace Corps; U.S. Trade and Development Agency; and Departments of Agriculture, Commerce, and Energy)."
CRS In Focus, IF12036
Congressional Research Service: https://crsreports.congress.gov/