Climate Sensitivity To Changes In CO2 Has Been Overestimated.
March 21, 2014
New research has been published that shows that Climate Sensitivity to changes in CO2 has been overestimated by Climate Scientists. The issue of Climate Sensitivity is discussed in an article in the Economist Magazine and is a must read.
The top climate scientists in the world have acknowledged that the global temperatures are trending way below the temperature forecasts generated by their computer simulators despite climbing world CO2 release rates. The Climate Sensitivity to increases in CO2 has been over estimated by Scientists. This means that something is wrong with the theories and sensitivity assumptions in the computer models.
The concept of Anthropogenic Global Warming (AGW) is based on three main theories that each depend on the previous theory. The first theory is that the first doubling of CO2 will cause about 1 C of warming due to long wave back radiation from the increased CO2. This is called the Greenhouse Gas theory and the effect may be muted due to spectrum overlap between CO2 and water vapor. Subsequent doublings of CO2 concentration have minimal effect due to the logarithmic decline in back radiation. Therefore further Carbon Dioxide increases of any amount CAN NOT CAUSE dangerous levels of warming increases WITHOUT POSITIVE FEEDBACKS
The second theory is called the amplification or positive feedback theory. The 1 C warming is predicted to cause higher humidity and more clouds which should trap more heat. The problems are that clouds can also reflect sunlight or that water vapor can release heat at altitude by condensing into precipitation which then will cause cooling at lower altitudes. The net effect is most likely negative so the model temperature predictions based on positive feedbacks will be too high which is becoming apparent. Natural systems have negative feedbacks which means they are self correcting stable long term systems as positive feedback mean that a system is unstable and would terminate.
The climate models are programmed with assumptions that these large positive feedbacks will cause major runaway warming in the troposphere in lower latitudes but that predicted warming has not occurred in the actual balloon or satellite data. See graphs below which show prediction versus reality or see http://www.drroyspencer.com/2013/06/still-epic-fail-73-climate-models-vs-measurements-running-5-year-means/
The Economist article refers to various new peer reviewed studies that now estimate total climate sensitivity to increased CO2 is probably less than 2 C.
The second new article that has just been published in Nature-Geoscience from a high-profile international team led by Oxford scientists that estimates Transient Climate Response (TCR) at 1.3°C along with Equilibrium Climate Sensitivity at 2.0°C. The contributors include 14 lead authors of the latest Intergovernmental Panel on Climate Change (IPCC) Fifth Scientific Assessment Report(AR5) which also lowered the climate sensitivity. http://www.nature.com/ngeo/journal/v6/n6/full/ngeo1836.html
The third theory is that the estimated warming will be large enough to lead to bad catastrophic effects. The world has warmed about .8 C in the last 100 years with at least .4 C occurred before 1950 as natural rebound from the Little Ice Age. Low climate sensitivity estimates of less than 2 C can not lead to extreme weather as there is no scientific mechanism for CO2 to influence the climate without warming. No link has been established between mild warming and droughts, tornadoes or hurricanes. See Roger Pielke Jr link to Senate testimony in July http://rogerpielkejr.blogspot.ca/ and the recent IPCC AR5 report. The AR5 reported low confidence levels on any links between Climate Change and Catastrophic Events
Mild warming has many positive benefits like less fuel use, less cold deaths (see Europe and USA in recent cold winters), minor sea level rise and easier lives. Mild warming combined with higher CO2 concentrations also increases crop yields and greens the earth. http://science.nbcnews.com/_news/2013/06/01/18669647-global-greening-the-other-greenhouse-effect-is-underway?lite
This is great news for the world that the Climate Crisis has been over estimated and overstated. The hundred’s of billions that the world has spent to date is gone (not counting 100’s of billions on wind and solar) but the world will not have to spend the trillions that scientists and politicians have forecasted.