History of Climate Change

There is an interesting new book on Climate Science written by an Italian scientist Antonello Provenzale which I found both honest and informative.  In the first half of the book he reviews the unique features of the Earth which, after some near misses, eventually  allowed life to develop and flourish. The collision of the Earth and another planet (Theia) roughly the size of  Mars resulted in a molten fused mass of both being ejected. This eventually became the moon. The moon’s  stabilising effect on the Earth’s orbit and resultant volcanism eventually led 100s of millions of years later to life developing. These first organisms were single cell bacteria/Archea  life  forms in  shallow seas, among these were unique  cyanbacteria able to photosynthesise CO2 from the atmosphere, water and sunlight  to produce oxygen as a waste product. Initially the oxygen was rapidly eliminated combining with dissolved iron resulting in today’s rich iron deposits.

It was not till much later that oxygen began to accumulate in the atmosphere. Around 2.4 billion years ago sediments indicate that sulphur appeared in the oceans which then combined with iron to produce  pyrite and increasing phosphorus nutrients . This allowed Cyanbacteria to dominate  the oceans and eventually releasing oxygen into the atmosphere,  creating the “protective” ozone layer. However the increase in atmospheric oxygen also likely led to the  snowball earth ! The intense Archean greenhouse effect was likely mainly based on methane which increasing oxygen successfully removed ! The consequent deep freeze was eventually broken by the accumulation of CO2 from volcanoes.

The CO2 greenhouse effect, high  oxygen levels and the protective ozone layer led to the Cambrian explosion and eventually to us humans ! Now we too are changing the climate a little !

I think Provenzale does a good job describing current “warming”  and what climate models are really saying. In reality all climate models are “wrong”  in the sense that they fail to simulate the actual surface temperatures T on earth. However what they can simulate is the change in temperature DT.  The earth’s climate is immensely complicated so each model chooses approximations to various processes (clouds, aerosols, carbon cycle, albedo etc). They then adjust  levels of CO2.

For this reason both data and models can  only work with temperature “anomalies” normalised to an instrumental 30 year average temperature (climate). Consequently all models by definition must agree with the data during  the normalisation period – typically ending in 1990. In fact he states “Climate models are undoubtably imperfect tools but they are currently the only ones we have to represent our planet”.

His conclusions on climate change and action to remediate it are mostly mainstream, but I very much like the honesty and style of his book. It is a well balanced argument.


Posted in AGW, Climate Change | 10 Comments

June 2023 Global Temperature was 1.1 C

El Niño has returned in June with a consequent rise in the average monthly global temperature  anomaly to 1.1 C.  The annual average temperature after the first 6 months of 2023 is now ~ 0.96C. This roughly equals that of the 2016  El Niño year

Temperatures relative to a 1961-1990 norm.

These are the monthly temperatures  since 2010

There is an interesting proposal that ENSO is driven by the 18.6 year Lunar cycle. Clearly tides have a strong influence on oceans and their focus and strength depend on the lunar cycle. I have previously looked at lunar effects on the Arctic Oscillation, but ENSO is another obvious oscillation effect.

Is El Niño driven by the lunar cycle ?

Posted in AGW, climate science | 2 Comments

Global temperature update – April 2023

Average temperatures fell 0.1C in April to a value of 0.85C relative to the 1961-1990 baseline. This results in an annual average after the 4 months of 0.94C.

Monthly global temperature data updated for April 2023

The developing El Nino seems to have stalled in April

There is evidence of an El Nino effect but if anything it has weakened since March.

Finally a lot of fuss is being made of a higher than normal temperature fluctuation in the North Atlantic. The water being up to 1C warmer than normal

This is what the SST data (HadSST4) shows.  The data do not support such exceptionally high water temperatures in the North Atlantic.

Average temperatures for April over North Atlantic.

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