The world is now entering a new age of Nuclear Power which is being escalated by the promise of ‘untold benefits’ via the rapid development and deployment of AI (artificial intelligence) which will require HUGE amounts of energy. Governments consider AI as the next big technology drive to boost flagging western economies and therefore are keen that their countries are leaders in this new field.

To enable the energy capability required to drive AI, governments have concluded that a major enabling technology will include conventional nuclear as well as newly developed small modular reactors (SMR’s). As the name suggests – these are relatively small factory constructed units which can be mass produced and assembled quickly on small sites. Taxpayers globally are already funding the latest development of SMR’s although surprisingly there has been very little public debate or opposition of this technology? I personally have many reservations regarding this policy in terms of safety and long-term costs associated with waste and decommissioning of these plants along with the associated weapons risks as increases in nuclear/dirty material in circulation/transported will significantly increase the risks of this material becoming accessible by rogue players.

However, a potentially far larger and completely neglected issue that could arise from the renewed drive towards nuclear power is that associated with the vast amounts of heat that is produced. This heat is referred to as Anthropogenic Waste Heat (AWH) and is the heat produced by any fuel burning process. During the combustion of fossil or hydrocarbon fuels, carbon reacts with oxygen to produce carbon dioxide (CO2), hydrogen reacts with Oxygen to produce water (H2O) and this exothermal reaction also produces a lot of heat which is what we utilise to drive machinery and heat our homes and buildings. These ‘products’ of combustion are produced in known and stable quantities which have enabled climate scientists to closely match the evidence of CO2 increases in the atmosphere from burning these fuels with increasing global temperatures. The same is therefore also true with the production of water and heat. It can however

be appreciated that water in itself would not increase global temperatures – however, this is obviously not true with heat (AWH) which by its very nature will obviously assist in increasing the temperature of the atmosphere?

Why, then is AWH not considered to be an important contributor to climate warming when CO2 is? This is a good question although I believe the answer may not be as simple as scientists currently believe!

By comparing AWH to our planets natural heat source (the sun) – net solar energy absorbed by the earth accounts for around 99% whilst AWH currently accounts for around 1%. The amount of excess energy that has been absorbed by the earth system (mainly oceans) since the industrial revolution is measured to be many orders of magnitude greater than could be produced by AWH and so it is assumed that AWH has a ‘negligible’ effect in this respect.

It is therefore assumed that if AWH and H2O are not responsible then it must be CO2 that causes the primary increase in atmospheric warming – which seems completely logical. CO2 concentrations in the atmosphere have risen from pre industrialization levels of around 280 parts per million (ppm) to current levels of 420 ppm which is undoubtedly a significant increase – although 420 ppm still only represents around 0.04% of atmospheric gases. Obviously, scientists and engineers are aware that small variations can often have big effects although it is important that these are properly considered especially given that AWH at a level of 1% of solar heating could potentially be a more obvious candidate for warming than CO2 at 0.04 %?

Obviously this is not a fair comparison as AWH is heat and CO2 is a greenhouse gas (GHG) and they therefore interact quite differently with the climate. So what is it about the other greenhouse gases that makes CO2 so special? This is a good question and one which scientists have studied for decades and provided a comprehensive list of all the GHG’s and further categorized them in order of their ‘potency’. When these are considered it transpires that our old friend ‘water’ or more specifically ‘water vapour’ (W V) enters the arena as the most potent No1 GHG both in terms of its ability to absorb heat and also by its prevalence in the atmosphere – which although variable is thought to exist at levels between 0.2 – 4% volume !

Whilst there is currently debate regarding the total concentration of water vapour including clouds in the atmosphere and whether they are net absorbers or emitters of heat it seems that regardless of the accuracy of these measurements and assumptions that W V  is widely accepted as being the GHG that has most influence on our climate and temperature. In addition to this, it is concluded that W V volume increases by 7% with every 1°C increase in average global temperatures – therefore projecting that with a current post industrial average temperature increase of 1.5°C  atmospheric W V would have increased by over 10%.

My questions for consideration to climate scientists are:

If we were to consider increasing levels of AWH since industrialization now causing a 1% increase in total solar radiation – what could this translate to in terms of total increased atmospheric W V over that period?

What would the additional GHG effect of this increased W V be over this period?

If it transpires that W V is also a net solar absorber – could this account for some or even most of the additional stored heat in the oceans and earth system?

If so, how is this likely to effect the rate of future warming compared to a CO2 only scenario?

If it is found that an AWH/W V process has a significant and increasing climate warming effect – how would this change our evaluation of ‘climate smart’ technologies and would you agree that high heat emitting technologies such as nuclear and geothermal would no longer be a viable option?

Would this also change the current thinking regarding expensive and high energy consuming processes such as CO2 capture and storage?

I sincerely hope that myself and others are able to persuade climate scientists and institutions to review the current science based on the above as I am confident that the current models have not sufficiently taken account of AWH/W V effects. Even if we accept the current models to be correct, it is clear that with the exponential increase of AI power consumption that AWH and W V will have an increasing effect on our climate to the point where they will need to be treated as importantly or more than CO2 and the other non water based GHG’s!

 

Phil Selwyn  (CEO Water Powered Technologies) 3rd December 2024