Global warming – why trapping carbon may not work
Francis Sedgemore, Tuesday 14 July 2009 at 11:51 UTC
Carbon capture and storage – will it really help offset climate change?
While politicians talk of investing heavily in so-called ‘clean coal’ technologies, building a new generation of fossil fuel power plants, sequestering carbon dioxide and trapping the greenhouse gas deep underground, two Swedish scientists argue that this will have little effect on global warming.
Environmental engineers and renewable energy experts Bo Nordell and Bruno Gervet have calculated total energy emissions from the late 19th century to the present day, and say that using the increase in average global air temperature as a measure of global warming does not account for observed climate change. We must also take into account the total energy contained in the ground, ice sheets and oceans in order to accurately model climate change.
According to Nordell and Gervet’s calculations, heat energy accumulated in the atmosphere corresponds to only 6.6% of global warming. The rest is stored in the ground (31.5%), melting ice (33.4%) and sea water (28.5%). Net heat emissions between the years 1880 and 2000 correspond to almost three quarters of the heat accumulated during the period; the missing heat is due to the greenhouse effect, natural variations in climate and/or an underestimation of net heat emissions, the researchers say.
“Since net heat emissions accounts for most of the global warming there is no or little reason for carbon dioxide sequestration,” says Nordell. “The increasing carbon dioxide emissions merely show how most net heat is produced.”
The total energy argument also deals a heavy blow to the case for nuclear power. Nuclear fission may not produce carbon dioxide in the same way and at the same level as burning fossil fuels, but according to Nordell it produces heat emissions equivalent to three times the energy of the electricity it generates. Nuclear energy therefore contributes significantly to global warming.
I should point out that Nordell’s focus on ‘thermal pollution’ has been subject to some intense criticism in recent years. Its detractors say that the approach contradicts decades of previous research, and even violates basic physical principles. For example, citing the Stefan-Boltzmann law that governs thermal radiation by idealised ‘black bodies’, atmospheric physicists Jörg Gumbel and Henning Rodhe claim that thermal pollution is a hundred times smaller than anthropogenic climate forcing due to greenhouse gases.
Nordell is having none of this, and insists that the net outgoing heat radiated by the planet since 1880 is greater than the geothermal heat flow, which until then had been the major heat source. This, he says, points to heat from the global use of non-renewable energy sources as being the major cause of global warming.
This argument (also discussed here) will no doubt continue, and whoever is proved to be right, if anyone, the scholarly row is driving some very useful research on heat emissions in industrialised societies and their effect on the environment. We should expect to see revisions in the figures as models are improved and more data are collected.
Further reading
Feed the writer! 
Tuesday 14 July 2009 at 17:30 UTC
Just how much heat do we produce and how much has accumulated?
From the Copenhagen Climate Report we can see that there has been an accumulation of 15.9 x10e22 Joules of energy on the planet over the recent 42 year period. That works out to an average and continuous heating power requirement of 120 Terra Watts (calculated by dividing the energy by the total number of seconds in 42 years)
The total average world power production today is only 16 Terra Watts! Let’s say an average of 14 TW for the last 42 years. Assume 20% efficiency for the worlds power production, so that equals 11 TW (80%) average heat loss into the environment.
11 TW is only 9% of 120 Terra-Watts, the energy required to explain the heating over the recent 42 year period. And that assumes all of that waste industrial heat energy is trapped here as opposed to much of it being radiated out into space.
Another way to look at it is as a climate forcing in units of power per square meter of earths surface:
11 Terra Watts /510 Terra meters-square = 0.02 W/m2. Compare this to the current GW forcing estimate of 1.8 W/m2.
Heat pollution isn’t even in the order of magnitude required to account for global warming.
Tuesday 14 July 2009 at 20:41 UTC
If Gervet and his mentor Nordell are serious in claiming that the bulk of global warming is due to “thermal pollution”, then they are surely indulging in hyperbole. But 9% is not the same as the two orders of magnitude quoted by Gumbel and Rodhe, unless you focus on the climate forcing figures quoted by Dave Occam, for example. But there we must consider the validity of black body assumptions when applied to the complex, non-equilibrium system that is the Earth. Back of envelope calculations are not enough.
There is serious discussion about the contribution of waste heat to climate change. Part of that has to do with the prospect of tapping that waste heat and turning it into useful energy (see, for example, my article “Infrared antennas for solar energy generation”).
What is evident from recent discussions of the detail of anthropogenic climate change is that there remain significant uncertainties in some of the variables involved. As it happens, the more we learn, the worse it is. For example, sea level rise is likely to be significantly greater than the figures quoted by the IPCC.
We should keep an open mind when other hypotheses are put forward, no matter how controversial they may first appear. I too have my doubts about Nordell’s calculations, but there may be something in the core argument.
Wednesday 15 July 2009 at 02:32 UTC
What utter nonsense. Once again anti-nuclear fanatics inventing some ridiculous pseudo-science.
The total power production of humans on this Earth is 16 TW. The Solar Energy received by the Sun is 174,000 TW ! . Just Radioactive Decay in the Earth supplies 30 TW of heat energy.
Try heating up your local region on a cold winter day by idling thousands of vehicles and heating thousands of homes. Might make the whole city one or two degrees warmer – no effect whatsoever on a larger region.
The heat wasted by thermal power plants (can be used in CHP and Desalination Power Plants), is insignificant in its effect on global climate. And will remain so
by idling thousands of vehicles and heating thousands of homes. Might make the whole city one or two degrees warmer – no effect whatsoever on a larger region.
The heat wasted by thermal power plants (can be used in CHP and Desalination Power Plants), is insignicant in its effect on global climate. And will remain so.
Thursday 16 July 2009 at 08:40 UTC
The discussion of nuclear power benefits should not be restricted to the issues of heat and CO2 only. We benefit as well from reduction of pollution by hundreds of chemicals created by oil- or coal-burning power-plants.
Beside – what Warren Heath says. A minuscule fluctuation in solar output will easily hide all the heat energy produced by puny us. Bleh…
Thursday 16 July 2009 at 10:25 UTC
Snoopy – it’s not about the magnitude of solar irradiance of the Earth in direct comparison with the energy produced by humans. What matters is how the heat produced by us affects the planet’s atmosphere on local, regional and global scales. I too cannot accept Nordell’s contention that “thermal pollution” is largely responsible for global warming, but I’ll listen to anyone who argues that it could be a contributory factor.
It’s interesting how any discussion of Nordell’s science quickly degenerates into an ideological argument about nuclear power. A cursory Google search reveals that Mr Heath spends his time on various web forums expressing contempt for wind power, and praising nuclear.