Wednesday, June 24, 2020

16. The story so far


 

The main purpose of this blog has been to analyse the physics behind climate change, and then to compare what the basic physics and raw data are indicating with what the climate scientists are saying. These are the results so far.

Post 7 looked at the temperature trend in New Zealand and found that the overall mean temperature actually declined until 1940 before increasing slightly up to the present day. The overall temperature change was a slight rise, but only amounting to about 0.25 °C since the mid 19th century. This is much less than the 1 °C rise climate scientists claim.

Post 8 examined the temperature trend in New Zealand in more detail and found that the breakpoint adjustments made to the data by Berkeley Earth, that were intended to correct for data flaws, actually added more warming to the trend than was in the original data.

Post 9 looked at the noise spectrum of the New Zealand data and found evidence of self-similarity and scaling behaviour with a fractal dimension of about 0.25. This implies that long-term temperature records over several thousands of years should still see fluctuations between the average temperature each century of over 0.5 °C, even without human intervention. In other words, a temperature rise (or fall) of at least up to 1 °C over a century is likely to be fairly common over time, and perfectly natural.

Post 10 looked at the impact of Berkeley Earth's breakpoint adjustments on the scaling behaviour of the temperature records and found that they had a negative impact. In other words the integrity of the data appeared to decline rather than improve after the adjustments were made.

Post 11 looked at the degree of correlation between pairs of temperature records in New Zealand as a function of their distance apart. For the original data a strong linear negative trend was observed for the maximum possible correlation between station pairs over distances up to 3000 km. But again the effect of Berkeley Earth's breakpoint adjustments to the data was a negative one. This trend became less detectable after the adjustments had been made. The one-year and five-year moving average smoothed data did become more highly correlated though.

After analysing the physics that dictate how the Sun and the Earth's atmosphere interact to set the Earth's surface temperature in Post 13, I then explored the implications of direct heating or energy liberation by humans at the Earth's surface in Post 14. Calculations of this direct anthropogenic surface heating (DASH) showed that while human energy use only contributed an average increase of 0.013 °C to the current overall global temperature, this energy use was highly concentrated. It is practically zero over the oceans and the poles, but in the USA it leads to an average increase of almost 0.2 °C. This rises to 0.3 °C in Texas and 0.5 °C in Pennsylvania. Yet in Europe the increases are typically even greater. In England the increase is almost 0.7 °C, and in the Benelux countries almost 1.0 °C. Perhaps more significantly for our understanding of retreating glaciers, the mean temperature rise from this effect for all the alpine countries is at least 0.3 °C.

Finally in Post 15 I looked at the energy requirements for sea level rise (SLR). Recent papers have claimed that sea levels are rising by up to 3.5 mm per year while NOAA/NASA satellite data puts the rise at 3.1 mm per year. These values are non-trivial but are still a long way short of the rate needed to cause serious environmental problems over the next 100 years.

In upcoming posts I will examine more of the global temperature data. But given what I have discovered so far, it would be a surprise if the results were found to be as clear cut as climate scientists claim. Contrary to what many claim, the science is not settled, and the data is open to many interpretations. That is not to say that everything is hunky dory though. Far from it.



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