Tuesday, January 22, 2008

Global Warming: A debate

Rahul Banerjee: Dear Naga, I read your piece on global warming and also decided to read your note on development. The articles are very good. They can be enhanced further. Here are my suggestions in this regard.

1. In the discussion on global warming generally one fact that is totally omitted is that there is also the question of waste heat to be dealt with. Even if we manage technologically to generate energy with a minimum of GHG emissions there is no way in which waste heat can be eliminated or reduced beyond a point. According to the second law of thermodynamics all use of energy leads to the generation of waste heat, which then increases the disorder in the environment leading to situations like the hurricane Katrina. Thus technological solutions cannot tackle the problem totally. This will add substance to your thrust that the solution ultimately has to be a political one wherein alternative modes of development that are less resource and energy dependent have to be adopted. Invariably the less resource and energy dependent the model of development is the more it has to rely on egalitarian cooperation between human beings. The primitive communist societies are the best example. We need not go back so far but definitely there has to be some back tracking on energy use. So the discussion should also include the contribution of energy use to global warming independent of its connection with GHG emissions

2. The capitalist/consumerist mode of development dominates not just economically but ideologically also. The reason why it is sustaining itself is that even those who are disadvantaged by it are labouring under the delusion that consumerism will provide a solution to their ills. This delusion is maintained by propaganda through television mainly. Programmes like Indian idol, kaun banega krorpati and all the ad campaigns reinforce this delusion. Whereas the cold logic being put forward by the left does not find any place in the mainstream media. Thus without a discussion of the way in which capitalism/consumerism is being propagated by the media any discussion of development will be incomplete. People in India are more upset over the alleged injustice done to the Indian cricket team in Australia than with the myriad injustices being perpetrated against the poor every day.

Soumya Dutta: While Rahul's spirit certainly resonates, the "science" is not fully correct. You see, there is no fundamental difference between "heat" and energy in general; it is only about different forms.

It is true that no real (in contrast to theoretical) conversion process is fully reversible, and any energy conversion (what we loosely call production) will have "waste heat" thrown to its adiabatic environment - thereby contributing to net positive entropy (disorder). But there are several energy sources - in the form of heat, which when converted to other forms for our use - like mechanical motion or electricity from solar heat or surface geothermal- which do not add even a single BTU to the earths adiabatic environment.

That total heat was already present. This contrasts even with the nuclear (whether fission or fusion), where the energy of the nuclear strong force is unleashed and a large part (over70%)of it is released as "waste heat".

Another lack of understanding is that - even the portion which is converted to "useful energy", with whatever high or low 'efficiency'. Like electricity, fan motion, light etc -- all ultimately end up as heat in the adiabatic (thermally isolated) environment of the earth. So the full Fossil or Unleashed energy is released ultimately as heat to the earth’s lithosphere, not only the portion that is generally thought as "waste heat"
In contrast, the GHG blanket causes radiative forcing, by adding extra heat which was otherwise escaping to the exosphere & beyond, thus not contributing to the earths heat balance (though total energy remains the same). That is why GHG build-up driven GW is so important.

On Rahul's 2nd point, I agree with the spirit of his expression, but totally disagree with the contention that the "left" (of what, may I ask?) in India is putting a "cold logic" which will prevent capitalist markets Hot "Global Warming". You may ask him what is the left establishments in West Bengal or Kerala, doing differently from the 'Right' BJP or 'central' Congress - in terms of confronting capitalist market embrace or economic / policies??

If found suitable, you may forward this to Rahul. I hope this is taken in the right spirit, and no un-meant offence is taken.

Arun Bidani: Thanks for clarifying the science. My understanding of these issues is limited, though I did think there was a problem with what he was saying.

Felt similar things about the second point.

However, sometimes the 'spirit' of what someone is saying is equally important, as you have pointed out. To balance these two responses is always a challenge, but is the heart of any engagement in a wider context.

The thrust of his first argument of less energy and resource dependent paradigm of 'development' is I think a good one, and so is the point on equality & cooperation.

Similarly, the second argument has some merits if one interprets the 'left' in a broad 'anti-mainstream' sense, though what he says sustains the present system is a bit simplistic, it is again not without a degree of 'truth'.

Soumya Dutta: Let me clarify my very quick response of yesterday. I'll attempt to explain with simple illustrations / examples.

1. Rahul is certainly right when he says that the "waste heat" has to be taken into account. In fact, in several discourses, this has been touched upon; I’ve also used the waste heat calculations in my teacher’s workshops.

BUT, the understanding about what is the ultimate heat addition to the earth’s lithosphere needs improvement, and that's one important point. And "plain waste-heat" is not as dangerous as the GHG blanket, because nature has a way to radiate out heat at a much faster rate, when the radiating substance is at a little higher temperature (called the law of radiation, and the radiated energy is proportional to the 4th power of abs. temp. of the radiating body)

2. The statement that the 'waste heat' cannot but be added -- is from a lack of understanding of the energy processes - as energy is available in different forms, is tapped to be released or converted. Though his argument is true for popularly known thermodynamic processes of energy conversions, there are also non-thermodynamic processes (one is around for about a
Century, has been extensively used in spacecrafts, and is now being tried for home-units or cars etc -- enough hints, now name this).

3. AND, there are - as I pointed out - well known energy conversion tapping that do not contribute anything to either the so called "waste heat" or to GHG emission. Take the most widely known & used Solar Water Heaters. The energy or "heat" (as solar influx or insulation) was already there in the earths lithosphere, and for the time the water is hot in an insulated tank, it actually causes a minute cooling of the earths atmosphere- by taking out a little from the total energy present. BUT, this comes back to the atm. when we use the water, and it cools down to ambient temp. thus releasing heat to the atmosphere, w/o adding any GHG to it (of course, the one time energy & material consumption of manufacturing / transporting / installing.... the Solar Water heater will be there, with its one-time GHG emission, if done on carbon energy). But then, it is upto us humans, to decide how much energy & other consumption we define as "essential" or "desirable”. Sustainability limits are rather flexible here, unlike what Rahul says.

Similar processes go on in large scale in other energy conversion processes - both natural & 'man-made'. AND THE TOTAL SOLAR ENERGY POTENTIAL IS SEVERAL THOUSAND TIMES OUR PRESENT TOTAL CONSUMPTION. And for global warming to be tackled, we 'only' need to bring down our total CO2 emissions within 14 billion tons, the total CO2 sink capacity of the earth, and roughly half of what we emit today. This is technically very feasible, with several routes (and I can show this with some basic calculations and a map of the earth's surface). But the capitalist market economy will not adopt this route till there are other routes giving higher profit, with off-the-shelf 'modules'.

4. The assumptions (dear to us all - but highly susceptible to scientific analysis), that this will force (a) a reduced energy & material resource using society, and (b) egalitarian society with more cooperation and equity - are to be understood in the light of the very well demonstrated feasibility (the economic viability is a function of many other factors, and can change with lack of other forms of energy, and the opportunity cost of scarce energy) of more than one method of tapping the Sun, and other renewables.

That Capitalist market economy will not be able to turn to a solar (zero GHG and no 'waste heat’) or other such energy base and will collapse as a result - is a naive assumption at best (we had long, animated discussion on this in Mumbai, you remember). On this, I differ with Sagar Dhara, Vijju dada, and Arun. Apart from our fond desires or values, there are many other tangibles to take care of. A better understanding of the "developments" around will place us on a more sound footing.

5. Rahul is very right in the sense, that "Ultimately" we humans have to cut down on consumption, because it is not only the question of the total non-GHG, non waste-heat energy (though that is a very major factor), but also of many other resources, and not to forget, the ultimate question of whether humans will keep going like hungry beasts with all their learning & introspections??

Nagraj Adve: I'm not responding to the crux of your mail (will do so later), but just to some specific info re annual CO2 emissions, where you mention 14 Gt as half the annual CO2 emissions. Three small points about this data: one, I think 28 billion tons is only emissions from fossil fuels. It does not include CO2 emissions from deforestation, which I think is about 7 billion tons. Two, this data I think pertains to 2005, which given the rise of emissions in recent years, it's probably higher by about 2 Gt by now. Three, of course, the more deforestation, particularly in tropical areas, the less the Earth will absorb. As it is there is less absorption by the oceans. It's about 55% recently, down from 60% some decades back.
Will respond to more in your mail later.

Rahul Banerjee: Thanks for including me into this forum. I have never really applied my mind seriously to the issue of global warming and so it will do me a world of good to engage with you on this thorny issue. Soumya's arguments are very good. Especially the one where he counters some other group member's hope of t he capitalist economy caving in. We have seen that it doesn't do that but instead is able to buy its way out continually.

I stressed on waste heat as an additional important factor in addition to the more important factor of GHG blanket. Because there is the GHG blanket, waste heat has become important and has to be taken into consideration. Solar energy is a non-GHG emitting source but its products should also be so. And harnessing solar energy should also not produce GHGs above the absorption limit. All this is now a problem area and not as simple as it is made to sound by Soumya.

In fact he shows the same hopefulness regarding the virtues of solar energy that others show about the collapse of capitalism. So also is waste heat recovery a problematic area whether through thermodynamic or non-thermodynamic processes because these processes are all very costly at present. In fact use of human energy as opposed to any other form of energy should also be explored in greater detail as it is being grossly under and misutilised at present.

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