Moreira is a professor at the University of São Paulo's Institute of Energy and Environment. His areas of expertise include biofuels, energy efficiency, and emerging mitigation techniques for greenhouse gases. His past positions include undersecretary of energy in Brazil's Federal Ministry of Mines and Energy. He has cofounded organizations including the Brazilian Petroleum Conservation Program and the Brazilian Biomass Reference Centre. In 2007, together with the other members of the Intergovernmental Panel on Climate Change, he was awarded the Nobel Peace Prize. He received a doctorate in physics from the University of São Paulo in 1971.