The two spikes around 1983 and 1993 were a consequence of volcanic eruptions injecting material into the stratosphere resulting in short term warming of the lower stratosphere. (newclimatemodel.com)
It means less short term warming at the surface but at the expense of a greater earlier long - term warming, and faster sea level rise. (realclimate.org)
It is argued that the advantage of such a change would be to more rapidly reduce short term warming and buy time for CO2 reductions. (climateanalytics.org)