Stemming Warming and Augmenting Pay Act of 2019 or the SWAP Act. This bill imposes a tax on combusted fossil fuel greenhouse gas emissions. The tax is equal to $30 per metric ton of carbon dioxide equivalent emissions beginning in 2021. The tax increases by 5% plus inflation each year and increases by $3 per ton every two years if the previous year's emission goals are not met. The revenue from such tax is divided (1) 70% for the reduction of payroll taxes; (2) 10% for additional payments to Social Security beneficiaries, and (3) 20% to establish a carbon trust fund for block grants to offset higher energy costs for low-income households, climate adaptation, energy efficiency, carbon sequestration, and research and development programs. The bill also amends the Clean Air Act to impose a 12-year moratorium on regulations that limit greenhouse gas emissions. This moratorium may be lifted if certain emission targets are not met.