The Congressional Budget Office in its 2017 Long-Term Budget Outlook issued a dire warning to D.C. policymakers about the likely consequences of continued inaction on the budget deficit.

Thanks largely to the growing costs for programs like Medicare and Social Security, the federal debt will reach 150 percent of gross domestic product by 2047, the CBO projected, up from an expected 77 percent at the end of this year. CBO projections assume that federal policy stays the same and calculates outcomes based on the expected changes in other factors like health-care costs, interest rates, productivity growth and labor force participation.

That 150 percent expected debt level is based on the most likely value for each of those variables. For example, as the Fed raises interest rates from historic lows, the existing debt will be more expensive to finance. Health-care costs are expected to continue to grow faster than inflation. If economic circumstances are worse than expected, public debt could balloon even faster.