Lower stratospheric cooling is mainly caused by the effects of ozone depletion with a possible contribution from increased stratospheric water vapor and greenhouse gases increase. There has been a decline in stratospheric temperatures, interspersed by warmings related to volcanic eruptions. Global Warming theory suggests that the stratosphere should cool while the troposphere warms. thumb|Top of the stratosphere (TTS) 1979–2006 temperature trend. The long term cooling in the lower stratosphere occurred in two downward steps in temperature both after the transient warming related to explosive volcanic eruptions of El Chichón and Mount Pinatubo, this behavior of the global stratospheric temperature has been attributed to global ozone concentration variation in the two years following volcanic eruptions. Since 1996 the trend is slightly positive due to ozone recovery juxtaposed to a cooling trend of 0.1K/decade that is consistent with the predicted impact of increased greenhouse gases.
Lower stratospheric cooling is mainly caused by the effects of ozone depletion with a possible contribution from increased stratospheric water vapor and greenhouse gases increase There has been a decline in stratospheric temperatures interspersed by warmings related to volcanic eruptions Global Warming theory suggests that the stratosphere should cool while the troposphere warms thumb|Top of the stratosphere (TTS) 1979–2006 temperature trend The long term cooling in the lower stratosphere occurred in two downward steps in temperature both after the transient warming related to explosive volcanic eruptions of El Chichón and Mount Pinatubo this behavior of the global stratospheric temperature has been attributed to global ozone concentration variation in the two years following volcanic eruptions Since 1996 the trend is slightly positive due to ozone recovery juxtaposed to a cooling trend of 01K/decade that is consistent with the predicted impact of increased greenhouse gases