The most dangerous proposal in the new budget is the institution of a cap-and-trade system for carbon emissions. Indeed, the single largest source of new tax revenue in the budget going forward are these payments to be made by businesses for the right to emit excess carbon.
The goal is an 83% reduction in carbon emissions by 2050 compared to 2005 levels.
That would bring US per capita emissions of CO2 down to a level below what we had in the 1700s. As Steven Hayward wrote in the WSJ last April about an 80% reduction then on the table:
Begin with the current inventory of carbon dioxide emissions