She’s written up the conclusions that she presented to the Senate yesterday:
If the recent warming hiatus is caused by natural variability, then this raises the question as to what extent the warming between 1975 and 2000 can also be explained by natural climate variability. In a recent journal publication, I provided a rationale for projecting that the hiatus in warming could extend to the 2030’s. By contrast, according to climate model projections, the probability of the hiatus extending beyond 20 years is vanishing small. If the hiatus does extend beyond 20 years, then a very substantial reconsideration will be needed of the 20th century attribution and the 21st century projections of climate change.
Attempts to modify the climate through reducing CO2 emissions may turn out to be futile. The stagnation in greenhouse warming observed over the past 15+ years demonstrates that CO2 is not a control knob that can fine tune climate variability on decadal and multi-decadal time scales. Even if CO2 mitigation strategies are successfully implemented and climate model projections are correct, an impact on the climate would not be expected for a number of decades. Further, solar variability, volcanic eruptions and natural internal climate variability will continue to be sources of unpredictable climate surprises.
As a result of the hiatus in warming, there is growing appreciation for the importance of natural climate variability on multi-decadal timescales. Further, the IPCC AR5 and Special Report on Extreme Events published in 2012, find little evidence that supports an increase in most extreme weather events that can be attributed to humans.
The perception that humans are causing an increase in extreme weather events is a primary motivation for the President’s Climate Change Plan. However, in the U.S., most types of weather extremes were worse in the 1930’s and even in the 1950’s than in the current climate, while the weather was overall more benign in the 1970’s. The extremes of the 1930’s and 1950’s are not attributable to greenhouse warming and are associated with natural climate variability (and in the case of the dustbowl drought and heat waves, also to land use practices). This sense that extreme weather events are now more frequent and intense is symptomatic of pre-1970 ‘weather amnesia’.
Not to mention wishful thinking. After all, it they can’t attribute current weather events to carbon, it takes away one more excuse for them to run our lives.