We analyze the role of board expertise in environmental issues (measured by the presence of non-executive directors with previous experience in environmental issues, EEDs) and director networks on GHG emissions. Using emission data of FTSE 350 firms, we show that the presence of EEDs on the board reduces GHG emissions. Also boards with better networked directors have better environmental performance. These associations are robust to alternative explanations - endogenous matching of firms and directors, general technical expertise of the board, and pro-active stacking in board composition. The results are consistent with the view that director skills and information spillovers through director networks add value.