Dear ladies and gentlemen,
During the energy crisis that has become visible in Germany and Europe over the past few months, things have gotten quieter about the supposedly imminent climate emergency. On the one hand, energy prices and security of supply have pushed the climate issue into the background. On the other hand, a weakening of the warming trend of the last 40 years is apparent.
The temperature curve of the satellite-based measurements of the University of Alabama UAH has been oscillating between -0.2 and 0.4 degrees for 20 years and seems to have remained stable since 2015, as shown in the next graph in the enlargement. (Source: woodfortrees). The mean value is drawn in green- it shows a slightly decreasing trend since 2015. Why hasn’t this been reported?
What are the reasons for this stagnation?
CO2 concentrations in the air have continued to rise unabated. It is true that global annual CO2 emissions have been more or less constant for some years now, at 40 billion tons of CO2. Slightly more than half is absorbed by the oceans and plants, so that currently each year the equivalent of about 2.5 ppm CO2 is added to the air concentration. In 2015, there were 401 ppm of CO2 in the air; in 2021, there were 416 ppm. At this rate, by the way, we would never reach the IPCC’s scary scenarios of 800 to 1000 ppm in 2100.
No, the lack of warming must have other reason
What has been the amount of natural warming in the last 30 years?
And how big is the natural cooling in the next 30 years?
A change in global temperature can also happen naturally. We know that clouds have decreased by about 2% after the turn of the millennium, and that for the last ten years cloud cover has been stable at a low level. Second, there are oceanic temperature cycles such as the Atlantic Multidecadal Oscillation AMO, which increased sharply from 1980 to the beginning of this millennium (by 0.5 degrees, after all), has remained at maximum since then, and is now weakening slightly again (see next graph).
The United States Weather and Oceanographic Administration, NOAA, writes that the AMO can amplify anthropogenic warming in the warm phase and make it disappear in the cold phase. According to NOAA, the AMO is a naturally occurring change in North Atlantic temperatures that has occurred for at least 1000 years with alternating warm and cold phases of 20-40 years. Add to this the weakening solar radiation since 2008, and further significant warming beyond 1.5 degrees is unlikely in the next 30 years.
Sea ice melt has stalled
The stagnant trend of temperatures that has been observed for several years can also be seen in the halted decline in Arctic sea ice extent reported by the European Copernicus program in March (see next graph
This is actually good news.
Wouldn’t it be time for climate researchers to bring these trends to the attention of politicians and the public? After all, politicians are currently readjusting the priorities of energy supply. While until last year’s price explosion and the aftermath of the Ukraine war it was apparently taken for granted that climate impacts would be the sole determining factor for energy policy, we are all now being made aware of the importance of security of supply and price trends.
However, German policymakers are still reacting inadequately. They believe they can solve the problem of self-generated energy shortages due to the double phase-out of coal and nuclear energy by simply building more wind farms and solar plants. It must always be remembered that in 2021 the share of wind and solar energy was just over 5% of primary energy supply (oil, gas, coal, nuclear, renewables). Even in a good windy year, it would not be much more than 6%.
Politicians do not have the necessary courage to repeal the coal phase-out law, to stop the nuclear phase-out, to lift the natural gas fracking ban and the ban on CO2 capture at coal-fired power plants. Not yet.
Gas-fired power plants like the one in Leipzig are still being built to replace coal-fired power plants with domestic lignite. Industry is already further ahead. Volkswagen has postponed the conversion of two of its own coal-fired power plants into gas-fired power plants indefinitely. This statement by CEO Diess was not widely reported in Germany, but it was abroad.
The U.S. government is also repositioning itself. John Kerry, the U.S. government’s climate envoy, for whom the 1.5-degree target was previously the sole political guideline, is now putting things into perspective and, in view of skyrocketing energy prices, saying that 1.8 degrees should be quite sufficient as a target. China, India and Southeast Asia, whose growth path is threatened by the price explosion, are practicing a renaissance of coal production.
That’s where we should listen when Jochem Marotzke of the Max Planck Institute for Meteorology in Hamburg says: “It’s unrealistic to bring global emissions to zero by 2050… a 2.5 degree world is still better than a 3.5 degree world.”
Let us reassure Mr. Marotzke: a 2.5 degree world will not be achieved in this century because natural variations in climate dampen anthropogenic warming. Had this been adequately accounted for in climate models, we would all have been spared much public panic and flawed policy decisions.
With best wishes