Solar variability and the influence on our climate

Does the sun have an impact on climate change? How strong is the influence? Is there any influence at all?

In this post I am going to find answers to these questions, which will bring me closer to the answer for my main question. How strong is the human influence on climate change?

To start with, solar variability is quite difficult to measure. There are measurements from satellites since 1979, which shows a variation of ca. 0,1%. But it is difficult to interpret the results; you have to make an approximate estimation to erase false measurements and it is just a short-term observation, which makes this method imprecise.

Therefore, you can’t make a scientific statement, with just this method, concerning the connection between solar variability and climate change. (Joanna D. Haigh 2002)

But satellite measurements are not the only thing we can use to make a statement concerning the solar activity. Since 1600 scientist have recorded the number of sunspots (dark patches on the sun) and faculae (bright patches on the sun) and had connected them to the TSI (total solar irradiance). (Joanna D. Haigh 2002)

Figure 4: Joanna D. Haigh 2002

Without bothering you with physical details, how they actually accomplished that. You can all see, there is just a small correlation between the TSI and the surface temperature on the earth. But it is uncertain how strong this actually influences our climate. Mostly, because of unmentioned factors like volcanic eruptions or El Nino, which could have affected the climate as well. (Joanna D. Haigh 2002)

In this post, I just worked with one paper from Joanna D. Haigh 2002, so it is just one opinion and I just scratched the surface of the article, but I hope, I got the main points right.

I will end with a statement of the conclusion, which summarizes my post quite good.

“The warming that occurred during the latter half of the 20th century

cannot be ascribed entirely to solar influences.“(Joanna D. Haigh 2002)

Cooling period in 1940 - 1975

With the help of a comment on my last post, thanks for that, I finally figured out what the cooling period between 1940 -1975 may have caused.

It is quite good explained in the blog (http://manmadeclimatechange.blogspot.de/2015/10/correlation-between-co2-and-temperature.html) and in the paper from Thomson et al 2008. I will give you a short summary.

If you look at the following graph, you will see that the global temperature decline is mainly because of a temperature decline in the seawater temperature. In particular the temperature drop in 1945. The explanation for that is, according to the Thomson et al paper, a change in the methods of collecting temperature data. But not only in the change of the methods, but more in the problem of mixing different methods. Especially after WWII the nations, who were collecting data, changed from mainly UK to mainly US. Through this change it is now very difficult to evaluate the right temperature. This confusion could have caused the abrupt decline in temperature in 1945.

 Figure 3: Thomson et al 2008

 

To conclude, the argument used in the video loses meaningfulness.

Correlation between CO2 and temperature

After watching this video for the second time, I got an even more critical view on it. The way they are explaining their arguments seems a bit like a propaganda movie, especially in the end, where they criticising renewable energy sources like solar energy. It could be a propaganda movie for the oil industry. But notwithstanding they made some arguments, which I am going to prove. I will focus on, at my opinion, the main three of them.

·      They were saying that the correlation between CO2 rise and temperature rise are not that high. In particular at time after the Second World War. A time of economic boom with an immense increase of CO2. But at this time the climate was getting cooler. In addition, they pointed out that a rising temperature leads to an increased CO2 level. So they argued the opposite, not the temperature rises because of CO2, CO2 rises because of the temperature.

·      Another argument was, if there is a climate warming through CO2, it should be getting more warmer high in the end of the troposphere than the ground air temperature. According to them, the ground temperature rises more than the troposphere temperature.

·      The last argument was the sun. The sun always dominates our climate. So if something changes with the sun, our climate will change too. They observed the appearance of sunspots and connected them to the climate warming, it was a quite good correlation, even better than the CO2.

According to the statistics of the 5^th IPCC report from 2014, there is indeed no correlation between CO2 and temperature in the time 1950 – 1975. In particular the correlation between the anthropogenic CO2 and the temperature seems not to exist. 

Figure 1:  5^th IPCC report 2014

If you take a closer look just at the temperature, I found some graph in the 1^st IPCC report from 1990, you will see that our climate increased the temperature in two periods, from 1910 to 1940 and from 1940 to 1975. Between these two periods, were especially on the north hemisphere a cooler climate period. In the IPCC report is not real explanation for that, they are just speaking about some periodic changes in climate. But the main problem is, where is the connection to CO2? (1^st IPCC report 1990)

Figure 2:  1^st IPCC report 1990

I don’t like to admit it, but it seems the propaganda video at least made one good point. So far for today, soon I will be back with hopefully an explanation for the cooling period.

Why I choose this topic?

First of all, welcome to my blog!

In this blog I am going to write a discussion on the topic, is the recent climate change man made or maybe not. Although I already got an opinion on this discussion, I will try to be objective and will give both sides the same opportunities to convince.

I got the idea to write about this topic by watching, just by accident, a certain youtube video. I will give you the link below.

It is quite long and provocative with many not high quality arguments, but there where some better ones, which started me thinking. Man made climate change is just a theory, maybe even a paradigm, but no unquestioning truth. It is the best theory at the moment by far, but maybe there are better ones!? In this blog, I hope, I am going to find out.

So far for today, enjoy the video!