Climate Action Now Act This bill requires the President to develop and update annually a plan for the United States to meet its nationally determined contribution under the Paris Agreement on climate change. (Sec. 3) In addition, the bill prohibits federal funds from being used to withdraw from the agreement. (Sec. 4) The bill outlines what must be included in the plan, including descriptions of steps to (1) cut greenhouse gas emissions by 26%-28% below 2005 levels by 2025, and (2) confirm that other parties to the agreement with major economies are fulfilling their announced contributions. The President must seek and publish comments from the public when submitting and updating the plan. (Sec. 5) Within six months, the President must report on the effect of the Paris Agreement on clean energy job development in rural communities. (Sec. 6) Within six months, the President must also contract with the National Academy of Sciences to report on the potential impacts of a withdrawal by the United States from the agreement on the global economic competitiveness of the U.S. economy and on U.S. workers. (Sec. 8) Within one year, the Government Accountability Office must study and report on the impact of the plan on U.S. territories.