This research undercuts claims by greenhouse skeptics that no warming has occurred during the last two decades. Such claims are based on satellite measurements of temperatures in the troposphere, which show little or no warming since the beginning of the satellite record in 1979.
"Weather balloons and weather forecast models show that there's been a pronounced increase in the height of the global tropopause over the last two decades," Santer said. "Our best understanding is that this increase is due to two factors: warming of troposphere, which is caused by increasing greenhouse gases, ...