In Donald Trump’s USA, H2O has already trumped CO2

As long as water vapour is in the atmosphere, it is a far more dangerous greenhouse gas than CO2, when it comes down after a fortnight or after a decade it could lead to snow storms, cyclones, etc. and once it has come down it could lead to landslides, flooding, etc. So are not all these different aspects of climate change?

Introduction

It was interesting to read Prof. Ajith de Alwis’s article titled ‘From rhetoric to reality: Hot air to a hot climate!’ which explained what the current thinking about climate change is and gave a glimpse of what we might be forced to experience in a few decades time. He talks about the emissions from American made Hummers, the new American President-elect’s much publicised stand on climate change, pronouncements of Dr. Svante Arrhenius about climate change, and the possible benefits of a climate change as perceived by them.

The whole argument revolves around the less harmful CO2 molecule and ignores the much more dangerous molecules of H2O. Probably because climate change scientists worldwide say that only the CO2 emitted by the combustion of fossil fuels and from other sources leads to climate change and because the H2O vapour which enters the atmosphere due to increased atmospheric temperature, arising from new carbon dioxide referred to earlier, does not bring about a direct climate change effect; but only an indirect “positive feedback”. What I intend to do in this article is to evaluate the impacts of CO2 and H2O from the same fossil fuel combustion and for this purpose I will use, as my basis, the article titled ‘Climate Change’ by Prof. John Seinfeld of Caltech University, published in Chemical Engineering Review in 2008.

Prof. Seinfeld on climate change

According to Prof. Seinfeld, when the atmospheric CO2 concentration – volumetric or molecular, and not gravimetric – reaches 560ppm, which is twice that prior to the industrial revolution which was 280ppm, the atmospheric temperature will increase by 1.20 degrees Celsius in order to equilibrate the earth’s energy balance to this change in CO2 concentration. This is calculated using the appropriate values of radiative forcing and Stefan-Boltzmann’s Constant. Please note that this computation of temperature increase does not take into consideration any water vapour formed along with CO2 during the combustion of fossil fuels. According to ‘Sustainable Energy - Choosing among options’ by Prof. Jefferson W. Tester, Professor of Sustainable Energy Systems at Cornell University and five other professors at Massachusetts Institute of Technology (Table 8.1), the atomic ratio of H:C in oil and gas are 2:1 and 4:1 respectively.

So as long as some oil and gas is burnt in getting the necessary energy, there would definitely be some water vapour formed as well. According to International Energy Agency’s 2013 report, we have burnt about 3.7Gt of oil and 2.28Gt of gas in 2011 and this would have generated a total of 9.8Gt of H2O in addition to the 31.2 Gt of CO2 from the combustion of above mentioned quantities of oil and gas and 6.0 Gt of coal.

So one could see that year after year we have kept on generating giga tons of H2O along with the respective giga tons of CO2. This water vapour is conveniently and deliberately - deliberately because then only can you promote usage of gas in the name of reducing climate change - ignored by climate change scientists worldwide.

They justify this ignoring of H2O by saying that H2O vapour’s residence time in the atmosphere is only about two weeks, which may be true of water vapour from transpiration and evaporation from water bodies, compared to more than a decade for CO2.

Prof. Seinfeld uses the climate sensitivity calculated from the changes during the glacial-interglacial period and the perturbation due to doubling of CO2 concentration to arrive at the figure of 2.80 C as the total increase in temperature from this doubling of CO2 concentration. It is interesting to note that out of this 2.80 C rise in temperature, 1.20 C is attributed to the doubling of CO2 concentration, while the balance 1.60 C is attributed to water vapour that would enter the atmosphere in order to maintain the same relative humidity even at this 1.20 C higher atmospheric temperature, due to new CO2. This is why this effect due to water vapour is considered a positive feedback effect.

If we apply this to what happened in 2011 when we generated 31.2Gt of CO2 and 9.8Gt of H2O, it would work out as follows.

Please note that these are only reasonable approximations to assist our understanding of what happens when we burn fossil fuels with hydrogen. I know that the relationship between these concentrations and temperature increases are not linear relationships and increases in water vapour in the atmosphere are determined by the Clasius-Clapeyron Equation.

Temperature increases due to 31.2Gt of CO2 is 0.0170C (corresponding to 1.20C in Section 1).

Increase in water vapour in the atmosphere due to this temperature increase to maintain constant relative humidity is 18.76Gt.

Temperature increase due to this increase of water vapour in the atmosphere is 0.0220C (corresponding to 1.60C in Section 3).

Temperature increases possible due to 9.8Gt of H2O from fossil fuel combustion is 0.0110C (based on the above three statements)

Possible increase in water vapour in the atmosphere due to this 0.0110C rise in temperature is 12.1Gt (based on the above three statements).

From these figures it is evident that H2O formed by combustion of gas and oil lead to an increase in temperature (0.0110C), which would be sufficient to sustain this 9.8Gt (less than 12.1Gt above) of water vapour formed and this would be a direct impact. In case this is not possible due to the lower residence time of water vapour in the atmosphere, then the same should be applicable to the water vapour mentioned above (3).

Please also note that the 9.8Gt mentioned above gets into the atmosphere along with the 31.2Gt of CO2 i.e. before any water vapour (18.7Gt given above) gets into the atmosphere to bring about a feedback effect for that 31.2Gt of CO2 and as such this 9.8Gt cannot precipitate, while the later 18.7Gt will remain in the atmosphere.

From the above you can see that when we talk about this 2.80C rise in temperature due to 560ppm of CO2 concentration, we had ignored a significant increase due to H2O from combustion of fossil fuels containing hydrogen and the moment this additional increase is taken into consideration, the temperature increase would be much more. The IEA report acknowledges this additional increase when they say that it would be rather 3.60C and not 2.80C as the anticipated increase in temperature due to doubling of CO2 concentration in the atmosphere. So IEA has accepted this fact of a direct impact from water vapour in an indirect fashion.

Global warming vs climate change

When we were talking about global warming those days this concentration of our attention only on the temperature increase would have been acceptable. But the moment we start talking about climate change we need to talk about the variation in climate parameters – temperature, precipitation and wind – of our climate system consisting of atmosphere, biosphere, cryosphere, hydrosphere and land area. 

In this respect, CO2 will influence the climate system as long as it stays in the atmosphere and the moment it is either absorbed by vegetation during photosynthesis or by oceans making ocean water more acidic, after a few decades we would not feel any ill effects of CO2. But water vapour is different, as long as it is in the atmosphere it is a far more dangerous greenhouse gas than CO2, when it comes down after a fortnight or after a decade it could lead to snow storms, cyclones, etc. and once it has come down it could lead to landslides, flooding etc. So are not all these different aspects of climate change?

When we say that the residence time of a water vapour molecule in the atmosphere is only two weeks, what we mean is that a water vapour molecule in the atmosphere in general makes about 40 trips up and down during a one year period. Just imagine the new water vapour molecules making 40 trips up and down bringing about the maleffects we mentioned in the above paragraph. Fortunately for us, new water vapour generated by our fossil fuel combustion does not make anything close to 40 such trips; but only about one and a half trips per year.

What we also need to remember is that just as much as CO2 has a residence time of a few decades in the atmosphere, this newly formed water molecules have a residence time of a few decades in the climate system, changing places and bringing in change, sometimes beneficial and other times harmful. We have no known mechanism to keep it away; when we build a wall to keep it away in the liquid form, it goes up and comes down, thumping on us and bringing about unimaginable destruction to all types of human and natural assets.

H2O has already trumped CO2

Just as Dr. Svante Arrhenius and his contemporaries wished for a reasonable amount of global warming just to make their lives more comfortable, the average Americans or average citizens in colder climes worldwide might prefer to have a slight increase in the normal temperature in their parts of the world. The only issue they would not like is the melting of the ice caps which would lead to coastal flooding. 

When the use of natural gas by the heavy vehicles in USA and the enhanced use of natural gas to replace coal power plants led to Hurricane Sandy and others along the eastern shore line, Americans thought that walls built along the coastline - like what they are supposed to be building at New York, New Orleans and San Francisco - would prevent additional water from melting ice caps upsetting the American dream. 

They were proudly talking about these adaptation strategies and their affluence to spend billions of dollars on such adaptation measures and the ability to protect themselves from climate change. But this year, the beating had been not from the ocean waters but from Hurricane Mathew (Which made landfall in Florida in September but the additional water on the ground was bothering South Carolina well into November) and many other similar water-related disasters which cleared the barricades built or to be built along the shoreline. Its impact on the real estate and tourism industries in the affected areas will leave its indelible mark on the American economy for a few decades at least.

The magnitude of these could be visualised from the news item carried by New York Times, which said that from May 2015 to September 2016, USA has experienced eight disasters the likes of which are expected only once in 500 years. Now you can see the magnitude of climate change. Another interesting aspect of this New York Times news item is that it could be used to calculate the speed of climate change. A once in 500 years type disaster could happen eight times only if the globe makes 4000 orbits around the sun - what climate change has done is that it has made the earth experience changes associated with 3000 orbits around the sun while actually making only one orbit. Isn’t this frightening enough? Of course, I read that somebody had said that every cyclone is not due to climate change. But when eight such events hammer you in a short span of 16 months, what else shall we attribute it to?

Another significant difference between H2O and CO2 is that while there is at least one natural process – photosynthesis – to convert this CO2 back into O2, even after a few decades, there is no single natural process to reconvert this new H2O back into O2. What this implies is that O2 in the atmosphere gets depleted all the time and the amount of water in the global water cycle increases all the time. After a considerably long period of time, people would have to resort to electrolysis of water, using renewable energy to have oxygen for somebody with breathing difficulties.

So what we propose is that before the global community – including America – starts feeling the real impact of global warming, with higher temperatures due to enhanced concentration of CO2 and melted ice caps, as per their expectations, all of us will feel the effects of enormous amounts of new water vapour entering the atmosphere due to the combustion of hydrogen containing fossil fuels; whether the residence time of the water molecule in the atmosphere is two weeks or more is irrelevant, probably we would wish it spends more time in the atmosphere. Water related disasters have struck the Americans well ahead of CO2 related exigencies which everybody was preparing to face.

Does it not amount to H2O trumping CO2 at least in the United States of America? We do not want Americans (or anybody for that matter) to suffer from more water related disasters.

(The writer is Managing Director at Somaratna Consultants Ltd.)