It is claimed by the IPCC that the increase in CO2 over the past century is entirely man-made and caused by CO2 emissions from the combustion of fossil fuels. Man-made “anthropogenic” global warming theory (or AGW) claims that energy man-made CO2 emissions are the main driver for the increase in measured global average temperatures and the resulting climate change.
CO2 content in the atmosphere is about 2.800 Bt = 0,04% of the total atmosphere. Our planet emits and also takes up again a total estimated of 1.200-1.900 Bt carbon dioxide each year. Of this amount, only a fraction of 57-64 Bt (3-5%) are man-made CO2 and only 14 Bt or about 1% originate from combustion of coal. However, 27-32 Bt CO2 or about 2% originate from animal agriculture. The remaining carbon dioxide is naturally released from oceans, microbes, insects, permafrost, volcanos, forest life and mammals. CO2 is stored in the form of carbon in marine sediments, ocean water, soil, vegetation, and organic matter. The total carbon stored near the surface of the Earth is 100.000 times higher than the entire CO2-equivalent in the atmosphere.
There is no doubt that fossil fuel burn emits CO2 to the atmosphere, but it is miniscule. Atmospheric carbon dioxide has increased and decreased in the planets history without human fossil fuel burn. Water vapor – and clouds are made of water – is considered the main “greenhouse gas” and is accepted as being the main driver of local weather.
The following illustration shows that the CO2 content in the atmosphere does not correlate with fossil fuel burn, but rather temperature and tends to be higher around the equator.
Satellite Images of CO2 Concentration October-November 2014
Professor Salby, a former IPCC scientist, points out that there is in fact no statistical warming since 1997 until 2014 and that CO2 concentration measured do not match up with industrial activity. In fact, the carbon dioxide concentration matches more with temperature, and temperature with solar activity.
For further information and discussion about the environmental effects of coal, please refer to Dr. Lars Schernikau’s article “Why CO2 is not the problem (what really causes weather and climate change)”.
Efficiency of Coal Power Plants
Source: Deutsche Bank (2007); Dr. Lars Schernikau: “Economics of the International Coal Trade – The Renaissance of Steam Coal”, Springer 2010.
Future technologies are expected to increase power plant efficiencies to 60% or more. However, this has little impact on the present challenge of capturing and storing carbon dioxide. Engineers are currently working with three principal technologies for CCS. There are a number of processes known today to “extract” CO2 from power plant emissions.
Flue-Gas Scrubbing in Conventional Power Plants
The advantage of this process is that it can be used with any existing conventional power plant. The major disadvantage is that the efficiency is reduced from about 42% (in Germany) to 28%, a large sacrifice. The technology works by separating the CO2 from the de-dusted and de-sulphurized flue gas in an additional scrubbing stage under atmospheric pressure.
In this process, the combustion of the fossil fuel occurs not with air but with recirculated CO2 and oxygen. Since the flue gas now consists largely of CO2, it can be captured without any additional scrubbing stage. Thus, power plants using this process can currently reach efficiencies of up to 37%.
Integrated Gasification Combined Cycle (IGCC) Process
This process is currently the most promising. The CO2 is actually captured before combusting the fuel. The fuel is gasified, the CO2 is separated, and then the gasified fuel is combusted in a gas turbine. The IGCC process currently reaches efficiencies of up to 40%, thus almost reaching the current standard of power plant efficiency. This process is also the least expensive. Nevertheless, it is estimated that the investment required for an IGCC power plant is up to 80% higher than that for a conventional power plant.
Carbon capture and storage (CCS) will not be covered here in more detail because it is not believed that man-made energy CO2 emissions have any impact on the global climate as shown in the section Environment & Coal