I believe the answer is: by proposing that the state legislature fund it in the budget
After the program is proposed to the state legislature, the legislature would review the program and determine whether the change is necessary and whether the states have all the necessary fund to actualise the program in that current years. If the proposal passed the review, the fund would be available for the government to spend.
The total temperature change between 3 km and 7 km above Earth's surface is around -20c and -15c.
