Space Scientists, can we build sensitive enough instruments to put an observatory at the point of the Earth's

shadow and measure the energy radiating off the dark side of the earth and 12 hours earlier measure the amount of energy being received on the sunlit side so we can compare the two measurements and aculate the data over a period of years to prove the earth is warming up or cooling off and how fast? I'm thinking of the Earth as a bomb calorimeter in a vacuum flask with a light shining on one side and reradiation of energy permited on the other. Any difference should be global change regardless of the source. Do we have the technology to do this accurately?