According to a report in ENN (Environmental News Network), the scientist in question is Hans-Joachim Schellnhuber, director of the Potsdam Institute for Climate Research, in Germany.
"Aerosols, or particles suspended in air, have a cooling effect on the Earth, countering global warming linked to carbon dioxide," said Schellnhuber.
"A drop in aerosols in the atmosphere could cause a "rapid" rise in temperatures," he added.
Airborne pollutants act as an umbrella worldwide while CO2 (carbon dioxide) provides insulation, trapping heat attempting to escape into the atmosphere.
A rise in temperature because of declines in aerosols in the atmosphere can be offset by slashing CO2 emissions, according to Schellnhuber.
By not reducing carbon output, humanity "is closing the last door we have through which we can possibly influence the global climate," he said.