The most recent IPCC Summary for Policy Makers with its dire predictions for the next decade and beyond suggest that there is a stronger basis for its predictions of catastrophic consequences and actions to avoid them. The only thing that seems to be new is the fact that major signatories to the Paris Accords are either ignoring their obligations or are finding them unrealistic.
The IPCC implies that the global climate situation has gotten worse but It hasn’t. Roy Spencer regularly publishes global satellite temperature measurements. This is the latest.
As Spencer points out, “The linear temperature trend of the global average lower tropospheric temperature anomalies from January 1979 through September 2018 remains at +0.13 C/decade.” In spite of continuing increases in atmospheric CO2 concentrations, there has been no matching increase in global temperatures.
These data are consistent with the lower estimates of climate sensitivity—the amount of warming from a doubling of CO2. The IPCC in its most recent Scientific Assessment Report estimated that climate sensitivity was between 1.5 degrees C and 4.5 degrees C. A 2018 study by climate scientists Judith Curry and Nic Lewis, published in the August edition of Journal of Climate, estimates climate sensitivity to be 1.2 degrees C. In addition, work by Dick Lindzen—Constraining Possibilities Versus Signal Detection, NAS Press–showed that the relationship between Co2 and warming is logarithmic and given the likely sensitivity, it would take over a century for increased CO2 to increase temperatures by another 1 degree C.
The IPCC proposed actions are so severe—electrifying all on-road transportation, pulling CO2 from the atmosphere, and employing carbon capture technology which is unproven—that it is hard to take them seriously. EU nations, the drivers of the Paris Accords, are not being aggressive and Germany has concluded that its 2020 target is unachievable. Angela Merkel has now become doubtful about the more aggressive targets since European nations are struggling to meet existing ones.
According to a New York Times Magazine article–NYT Mag—the actions to achieve the Paris accords are fantasy. And, the IPCC predictions follow on 30 years of failed predictions. A little over 10 years ago, Al Gore and Jim Hansen predicted that we only had 10 to take IPCC like actions. As Pat Michaels wrote this past June, “… it’s time to acknowledge that the rapid warming he ( Hansen) predicted isn’t happening. … policy makers should adopt the more modest forecasts that are consistent with observed temperatures. That would be a lukewarm policy, consistent with a lukewarming planet.
All of this leads to a conclusion that the IPCC report is an attempt to regain relevance and continue the lifestyle its members have become accustomed to.