Any frequent reader of this blog knows I think the United Nations International Panel on Climate Change (IPCC) has been practicing sloppy science for at least the last 20 years. Wild Ass Guesses are their stock and trade. I thought I’d take a few blogs to better explain myself.
Today’ Subject: Climate Forcing
The IPCC has been writing Synopsis Reports since 1992. The latest is nicknamed AR4 (The 4th Assessment Report). It was published in September of 2007. UN Scientists (and politicians too because it is the UN) are working on AR5 right now. It should be ready for public consumption in 2014.
The IPCC says the following in bold print in the beginning of section 2.4 of the 2007 Report:
Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations.
The term very likely is a defined term in the document which means that they are more than 90% certain but less than 95% certain. Unfortunately most is not a defined term. I’d guess they mean greater than 50 percent. The document never defines most and is silent about all other possible reasons the world has warmed. Man caused greenhouse gases (GHG) are the only subject discussed.
The document begins with the statement that the IPCC is 90% certain that man is responsible for more than 50% of the increase in worldwide temperatures since 1950. The rest of the document is constructed around the assumption that man is responsible for measured changes seen in recent years.
Recent temperature increases are considered confirmation that they are correct. Temperatures that are well within the range of normal climate variation. OK?
Early in Chapter 2 of the 2007 Report, a graph is presented that explains the forcing agents behind global climate change (Figure 2.4). Here it is:
This chart drives me crazy! LOSU means level of scientific understanding. This chart says the IPCC knows a lot about long lived greenhouse gases (high LOSU) and nearly nothing about everything else including Aerosols and the Sun (both are low LOSU). It also says that greenhouse gases are 22 times more important than changes in the Sun. The math looks like this:
Everything shown on the chart is anthropogenic except Solar Irradiance. If so, where do ice ages come from?
The IPCC states that before 1950 most warming was natural climate variation. The AR4 document appears to be saying that variation in Solar Radiation reaching the earth surface is always a very small number and only contributes to warming, and never contributes to cooling.
Here is an Antarctic Ice Core, the Vostok Ice Core: (http://rubyelephant.files.wordpress.com/2007/12/vostok-ice-core.jpg)
Wow look at all that natural variation; 400,000 years worth. About 12 degrees C of natural climate variation. 3 degrees warmer than 1950 and 9 degrees colder. And even today we are within the very tight range of the last 11,000 years…a period of nearly no change.
The temperature changes in a cycle that averages about 100,000 years. Today, and for the last 11,000 years, it has been warm. Less warm than 130,00o years ago but much more stable. Solar Irridiance must have been much less than it is today just 20,000 years ago.
The IPCC says in the Synopses document that their Solar data is based upon the time period from 1750 to 2005. It appears that the IPCC has taken a period of stable warming climate…and then assumed that is the only condition that can exist. If they had started say….500 years earlier… the results would have been different.
Look at the Aerosol numbers in the chart. It could be very small or bigger than carbon dioxide….and the IPCC admits to now knowing much about it
And carbon dioxide appears to be a trailing rather than a leading indicator as this image demonstrates:
130,000 years ago, carbon stayed stable while temperature dropped. And it lasted for 20,000 years. About 20,000 years later temperature rose rapidly while carbon dioxide levels drifted a bit lower. Recent data shows wild increases in carbon dioxide without the corresponding temperature rise. A less than perfect correlation.
Other Vostok ice core images include dust particles in the graph. They show sudden increases in dust during some of the cooling periods. My guess….super volcano eruptions.
The IPCC admits to lots of areas where their knowledge is weak and they admit that Aerosols could be very important (the number could be large), they have used a simplistic model of the sun and admit they don’t know much about many important subjects. And they are 90% sure man is mostly responsible.
Can you say SWAG.
Science the IPCC way.