An overview of the CERES project is given in CERES, a review: Past, present and Future (2011):
- The Clouds and Earth Radiant Energy System (CERES) project’s objectives are to measure the reflected solar radiance (shortwave) and Earth-emitted (longwave) radiances and from these measurements to compute the shortwave and longwave radiation fluxes at the top of the atmosphere (TOA) and the surface and radiation divergence within the atmosphere. The fluxes at TOA are to be retrieved to an accuracy of 2%.
- The first objective of CERES is to measure OLR radiances to an accuracy of 1% and reflected solar radiances to 2%. The global mean OLR flux is approximately 240 W/m2, so the requirement is 2.4 W/m2 accuracy. Likewise the global mean reflected flux is 100 W/m2, thus the requirement for shortwave flux is 2 W/m2.
- Without any feedbacks, a doubling of CO2 (which amounts to a forcing of 3.7 W/m2) would result in 1 °C global warming, which is easy to calculate and is undisputed.
PS CERES is selling itself e.g. on a video telling us
- When you add greenhouse gasses such as CO2 and methane you change that radiation balance on the top of the atmosphere and you change the amount of outgoing radiation so that imbalance means more energy in the system...part of it goes into the ocean...and part of goes into actually warming the Earth...all of those things should give you a coherent picture of how things are changing as we warm the climate...