German Police

[aveatry]

Ok Johna I checked out the source of the BBC alarmist report and that graph and here is the Abstract in blue from the authors And my comments in black bold.

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Including an exceptionally warm Northern Hemisphere summer 2023 has been reported as the hottest year on record. however, because the sparse 19th century meteorological records tend to be too warm.
So when coming up with their figures of a big rise they are ignoring pre industrial warm periods because otherwise it would not look like such a big rise, and they are only talking about the northern hemisphere.
Here, we combine observed and reconstructed June-August surface air temperatures to show that 2023 was the warmest Northern Hemisphere extra-tropical summer over the past 2000 years exceeding the 95% confidence range of natural climate variability by more than half a degree Celsius.
So strip out the warm periods that they do not like and the rise is still only 0.5C in 2,000 years

Comparison of the 2023 summer warming against the coldest reconstructed summer in 536 CE reveals a maximum range of pre-Anthropocene-to-2023 temperatures of 3.93°C.
So as I pointed out earlier they are comparing in their words (exceptionally warm Northern Hemisphere summer 2023 that is amplified by an unfolding El Niño event ) with the coldest summer in 536 caused by a volcano blocking out the sun to get 3.93 C
Although 2023 is consistent with a greenhouse gases-induced warming trend that is amplified by an unfolding El Niño event8, this extreme emphasizes the urgency to implement international agreements for carbon emission reduction.

 

[JonathanM]

While there is clear evidence that volcanoes do cause climatic cooling, evidence for them causing climatic warming is debatable at present.

As regards contemporary volcanoes that is true. But in the past, volcanism was several orders of magnitude higher. Also, they were usually under the sea, so the aerosols which provide the cooling effect never reached the atmosphere. But the CO2 did. This is one from about 60 million years ago, when the North Atlantic Ocean was formed.

The team found that the PETM was associated with a total input of more than 10,000 petagrams of carbon from a predominantly volcanic source. This is a vast amount of carbon – some 30 times larger than all the fossil fuels burned to date and equivalent to all current conventional and unconventional fossil fuel reserves. In their computer model simulations, it resulted in the concentration of atmospheric CO2 increasing from 800 parts per million to above 2000 ppm. The Earth’s mantle contains more than enough carbon to explain this dramatic rise and it would have been released as magma, pouring from volcanic rifts at the Earth’s surface.

https://www.southampton.ac.uk/news/2017/08/volcanoes-global-warming.page

 

[Brigadier]

As regards contemporary volcanoes that is true. But in the past, volcanism was several orders of magnitude higher. Also, they were usually under the sea, so the aerosols which provide the cooling effect never reached the atmosphere. But the CO2 did. This is one from about 60 million years ago, when the North Atlantic Ocean was formed.



https://www.southampton.ac.uk/news/2017/08/volcanoes-global-warming.page

And over millions of years.

Single (cooling) volcanoes were eruptions over the course of days, weeks, or months, usually.