Gen1GT Posted January 9, 2013 Posted January 9, 2013 I am not a professional in any field of science, let alone any related to climate science, but it seems to me we could be overlooking a huge piece of the puzzle in the blame for global warming. I do work in an engineering field, so the use of math and logic are not foreign to me. It seems as though Occam’s Razor has – as far as I can tell – yet to be observed in climate science related to global warming. Please consider the following: The average car in the world achieves 8L/100km of fuel consumption, according to the IEA (in 2005). The average passenger car travels 14,435 km in one year. (International Road Federation). The average thermodynamic efficiency of an internal combustion engine is 37%, leaving 63% of the burned fuel wasted as heat (courses.washington.edu) The average energy content of gasoline is 36 Megajoules per litre. According to my calculations (and you can feel free to check my math), the average car emits 26,190 MJ of heat energy into the atmosphere every year. To put that into relatable terms, this equals 24.8 million BTU’s of heat PER CAR, of which there are over a billion, per year! What is the possibility that CO2 plays a small role in global warming, but rather, we are actually simply heating up the planet by burning everything in sight? 24.8 million billion BTUs is a lot of heat in one year, but I can’t plug that number into the grand equation of global warming. In the current global warming model, does heat waste even factor into the formula?
iNow Posted January 9, 2013 Posted January 9, 2013 Hi Gen1GT - Welcome to the site. Your insight is actually a common one and has been explored. Here's the summary: The contribution of waste heat to the global climate is 0.028 W/m2. In contrast, the contribution from human greenhouse gases is 2.9 W/m2. Greenhouse warming is adding about 100 times more heat to our climate than waste heat. In short, waste heat accounts for only about 1% of the warming we're experiencing.
Gen1GT Posted January 10, 2013 Author Posted January 10, 2013 Hmm, after following that link and then another link within that link, they do not reference their source of waste heat only contributing only 0.028 W/m2. However, I did do the calculations, and passenger car heat emissions would be far less than 0.028 W/m2. Forgive my ignorance, and hopefully the search nazis don't slap my wrist, but is there a link to the formula for calculating the atmospheric temperature rise in relation to CO2 concentration (including explanation of the variables and their units)? ...and thanks for the welcome! I plan to spend more time in the physics section than in climate science section, but this particular question has always been in my mind.
swansont Posted January 10, 2013 Posted January 10, 2013 The average amount of solar energy incident on the atmosphere is about 1360 W/m^2. Changes in greenhouse gases only have to trap a small additional fraction of that to account for the warming. That's 1.75 x 10^17 Watts. Compare that to the 26 trillion Watts of waste heat from cars. (2.6 x 10^13). Matching that only requires trapping about an additional 0.015% of the solar radiation. The first-order warming effect from changes in CO2 is here: http://en.wikipedia.org/wiki/Radiative_forcing#Forcing_due_to_atmospheric_gas
iNow Posted January 10, 2013 Posted January 10, 2013 is there a link to the formula for calculating the atmospheric temperature rise in relation to CO2 concentration (including explanation of the variables and their units)? I'm unsure of the contents, but my previous link references this Flanner 2009 paper in Geophysical Research Letters as the source of their numbers, so I suspect methodology would be detailed there: http://onlinelibrary.wiley.com/doi/10.1029/2008GL036465/abstract That's paywalled, though, so there's a chance you may get farther with this one and the references contained therein: http://www.cgd.ucar.edu/tss/ahf/
John Cuthber Posted January 10, 2013 Posted January 10, 2013 Surely Occam's razor works the other way. We know there's more CO2 in the air and we know it traps IR. So, it's like saying that we put another blanket on the bed and we are warmer. The simplest explanation is that the blanket is why it's warmer.
swansont Posted January 10, 2013 Posted January 10, 2013 Surely Occam's razor works the other way. We know there's more CO2 in the air and we know it traps IR. So, it's like saying that we put another blanket on the bed and we are warmer. The simplest explanation is that the blanket is why it's warmer. But it's fair to say we generate more waste heat as well, since that tends to scale with population and economic growth, meaning you have more than one possible cause. We put on a blanket but we're also running a slight fever. One is obligated to run the numbers to see the relative sizes of the effects.
ralfy Posted January 10, 2013 Posted January 10, 2013 CO2 does not come only from cars, and may have a forcing and feedback factor. More details may be found in NAS reports and others.
overtone Posted January 10, 2013 Posted January 10, 2013 As a side note, in the larger think tank world the same people who assert that human production of waste heat accounts for a significant share of the melting of glaciers and warming of entire planetary atomospheres, oceans etc, are also claiming the human production of greenhouse gas is far too small to affect the climate of the whole planet, that human endeavor is puny and trivial compared with natural processes and patterns. So the problems in the public discussion are not merely those of ignorance or honest factual confusion.
John Cuthber Posted January 10, 2013 Posted January 10, 2013 But it's fair to say we generate more waste heat as well, since that tends to scale with population and economic growth, meaning you have more than one possible cause. We put on a blanket but we're also running a slight fever. One is obligated to run the numbers to see the relative sizes of the effects. True, if you want to see the size of the effects you need the numbers. But you can still say that both effects are real. As it were, even if we didn't have a bit of a fever, we would still get hotter- that's what blankets do. Re the OP's question " is there a link to the formula for calculating the atmospheric temperature rise in relation to CO2 concentration (including explanation of the variables and their units)?" The simple answer is no. It's enormously complicated because there are a whole bunch of feedback systems in place etc. If the atmosphere was fully mixed and isothermal, it would be easier but the effects of differencing temperatures and also different concentrations of gases at different heights make it a pig to calculate. Things like rain and storms also add to the difficulty.
Gen1GT Posted January 11, 2013 Author Posted January 11, 2013 True, if you want to see the size of the effects you need the numbers. But you can still say that both effects are real. As it were, even if we didn't have a bit of a fever, we would still get hotter- that's what blankets do. Re the OP's question " is there a link to the formula for calculating the atmospheric temperature rise in relation to CO2 concentration (including explanation of the variables and their units)?" The simple answer is no. It's enormously complicated because there are a whole bunch of feedback systems in place etc. If the atmosphere was fully mixed and isothermal, it would be easier but the effects of differencing temperatures and also different concentrations of gases at different heights make it a pig to calculate. Things like rain and storms also add to the difficulty. This is the problem I have with the climate cause and effect models and predictions. Every other branch of science has clear, accurate formulae and equations or laboratory repeatable experiments allowing anyone with the ability and desire to repeat the process to confirm the result. Who in the climate science industry can prove through experiments, or through accurate models entailing every single possible variable and interaction between those variables, an empirical result with little or no chance inaccuracy? Scientist A can measure red shift at Galaxy X to determine Distance Y. Scientist B can measure red shift at Galaxy X to confirm Distance Y using the same repeatable and agreed upon mathematical formula. Does this type of positive feedback not exist in climate science?
swansont Posted January 11, 2013 Posted January 11, 2013 This is the problem I have with the climate cause and effect models and predictions. Every other branch of science has clear, accurate formulae and equations or laboratory repeatable experiments allowing anyone with the ability and desire to repeat the process to confirm the result. Who in the climate science industry can prove through experiments, or through accurate models entailing every single possible variable and interaction between those variables, an empirical result with little or no chance inaccuracy? No, that's an unfair assessment. All experiment has error to it, and one of the characteristics of science is quantification of that error. Not, however, simple formulas or the ability to model all detail. Take thermodynamics. It came about because we can't model the actions of the individual components and instead we look at the aggregate behavior. Modeling of results in evolutionary biology is similarly done at the population level, AFAICT. Nobody is stopping anyone from modeling climate of they so desire. But the demand that it be simple is an unreasonable one. Scientist A can measure red shift at Galaxy X to determine Distance Y. Scientist B can measure red shift at Galaxy X to confirm Distance Y using the same repeatable and agreed upon mathematical formula. Does this type of positive feedback not exist in climate science? It exists. More than one group models climate and compares their results to the data that are collected. There are limits to how much independent data can be collected, just as there is limited telescope time for doing the observing and comparing you describe.
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