Before I continue I will say that I believe that the climate has changed, is changing and will continue to change. I believe that we should minimize our use of finite resources and that we should minimize our impact on the Earth. Using bad science to achieve this will not work in the long run.
Let’s start with the ‘scientific process’.
- Formulate a theory
- Use this theory to make some predictions
- Make some experiments/observations to confirm or deny these predictions
- Look for and try and remove confounding factors.
- Decide if the theory is valid.
- If the theory does not produce valid predictions refine/change the theory
Where does AGW sit with this?
- A theory was formulated that CO2 levels in the atmosphere are the main driver of global temperatures. All good.
- This theory was used to build a series of mathematical models based on Arrhenius’s ‘greenhouse’ model with a number of forcing functions to allow then to be calibrated to the historic records. These models then gave values for ‘Equilibrium Climate Sensitivity’ ECS, which is the expected temperature rise for a doubling of atmospheric CO2. The current ‘accepted’ values are 1.5-4.5°C. OK so far.
- We cannot easily experiment with the atmosphere but we can make observations of CO2 level and temperatures. Both are a bit difficult because they vary around the globe so some form of average has to be formulated and long term direct measured values are limited. The longest direct CO2 measurement (Mauna Loa series) only goes back to 1958. The longest direct temperature measurement (Central England Temperature) goes back to 1772. All older data has to be calculated from proxies. Ok so we can make some observations to check our theories but it is not so easy.
- There are a number of possible confounding factors including variations in the sun’s output and variations in the earths orbital path. These are confirmed to exist but their level of influence is not certain. They are not currently factored into the climate models because there is insufficient data. So we know that there are confounding factors but don’t know how big they are. Not so good
- These models have been around for a while now so how are their predictions shaping up? To keep with the ‘official’ view let’s start with the Last IPCC report, AR5. The graphs on slides 18 and 22 show that up to 2012 the actual temperatures (black line) reaching the bottom range of the model predictions (yellow band).What has happened since? Has the global average temperature jumped by more than 0.3°C? Have the model predictions reduced to match reality? The answer in both cases is no. These slides also note the lower rate of increase in global temperatures since 1998. Have the models explained this? The answer again is no. What did happen was that some NASA researchers manipulated the measurements to smooth out this change.
- Are the theories being refined to deal with the discrepancies? A clear no. We are told that the science is settled. The Paris agreement to maintain the temperature rise to 1.5°C above pre-industrial times is based on a badly defined ‘pre industrial temperature’and a CO2 sensitivity with and accepted range of 3-1 and a likely range that is significantly higher. The TCR(Transient Climate Response) and ECS in the published literature are falling continuously with time. Looking at the trends and the current climate response the ECS is likely to be around 1 or even less.
Some other points:
NASA launched the Orbiting Carbon Observatory 2 in 2014 with a view to supporting the manmade CO2 problem. The first results were posted in December 2014, but other than a concentration over part of China it did not support the idea that man was responsible for CO2 increases. It’s still up there collecting data, but it does not support AGW so no one talks about it anymore.
The disappearance of Arctic (and Antarctic) sea ice has been predicted for a number of years, it’s still there. David Hempleman-Adams made a well publicized sea voyage through the Arctic this year. It might have been meaningful if his skipper hadn’t already made the trip a couple of times.
There are many more examples of attempts to support a dying theory but I will leave it there for the moment. Maybe next we should look at the reality behind the so called renewable energy sources.
Best regards
Roger
