In his latest newsletter, German professor Fritz Vahrenholt reports how the global average temperature has decreased in June and early July 2025, and has seen a downward trend since January 2025. The deviation from the long-term average of satellite measurements is +0.48 degrees Celsius, with values continuing to drop in July.
Despite this global development, German public broadcasters and parties like the Green Party have been spreading panic about the summer heat. There are even preposterous demands for “heat days off” from work. The number of so-called summerlike days (i.e. temps 25°C and over) has increased from an average of 20-30 in the 1950s to 40-50 per year today.
However, according to Vahrenholt, the primary cause of the current warming observed between 2022 and 2024 is primarily natural phenomena and not CO2. These natural factors are 1) a strong El Niño and 2) an increase in direct solar radiation, attributed to the reduction of aerosols.
Based on NASA CERES satellite measurements from the last 25 years, 80% of the warming is due to cloud thinning and the resulting increase in direct shortwave solar radiation, while only 20% is attributed to the CO2 greenhouse effect. The climate models have not predicted an increase in shortwave radiation and that fewer clouds would actually weaken the greenhouse effect, contradicting the models.
Annual sunshine anomaly in hours for Germany since 1950. More sunshine means warmer temperatures. Reference period is 1961-1990. Source: DWD.
Vahrenholt also cites a connection between the Atlantic Multidecadal Oscillation (AMO) and cloud formation and sunshine duration. During high ocean temperatures, clouds are said to be more permeable, allowing more sunlight to pass through. This correlation is supported by a publication in Nature Scientific Reports, showing that sunshine duration follows the cycles of Atlantic temperatures (AMO).
Vahrenholt concludes that current climate policies in Europe and Germany, aiming for net-zero CO2 emissions by 2045, are based on inadequate models because they don’t sufficiently account for the essential mechanisms of warming (especially the role of clouds and direct solar radiation).
In summary, CO2 human CO2 emissions are not the primary driver of our climate. Instead, the main drivers are natural cycles and changes in aerosol concentrations and cloud formation.
My dear Pierre 🙂
I see you’re still posting the same misinformation you did in 2009. Do you actually believe this anti-scientific nonsense you’re peddling? Or are you so lost that you don’t? We both know that Vahrenholt is ex-RWE with an agenda, not a neutral, objective observer. But what’s in it for you? Why are you still fighting tooth and claw to be on the wrong side of history? The soviets called people like you “useful idiots”. Quite a legacy.
May god have mercy on your soul.
This is a review of the Hockeystick. All the climate change is natural and there is no science that supports CO2 as the cause.
https://app.screencast.com/nXfZcUyGR4QlR