As of 2013, the warming effect of long-lived greenhouse gases in Earth's atmosphere has increased by approximately 34% since 1990.

Verifying Greenhouse Gas Emissions

Agreements to limit emissions of greenhouse gases are currently the focus of international negotiations, and with such accords will come the need to accurately estimate these emissions, monitor their changes over time, and verify them with independent data. This report identifies strategic investments that could be made within 5 years to both improve self-reporting and yield a capability to verify these estimates and reduce uncertainties about emissions to less than 10 percent.