more cause-and-effect data needed on global warming

One of our Political Advisers has suggested that we need more cause-and-effect data for global warming consideration.
He says, "Support for "Congress to wake up and do everything in its power to reduce dangerous carbon pollution" (C&EN, Apr. 7, page 8) might be greater if someone could present data showing that changes in carbon dioxide concentration  between 0.03% and 0.05% in a mixture of gasses identical to those comprising our atmosphere cause any significant change in the transfer of heat.  Cause and effect studies, data or examples are sorely lacking in discussions concerning carbon dioxide/global warming, yet meaningless correlations are prevalent and the basis for political actions impacting our economy.  Climate change is occurring, has occurred since Earth was formed and will continue to occur, with or without any  input from humans."