Wednesday, May 04, 2016

Models

Dr. Long was a very elegant and refined Senior Professor. He could make a stick of chalk last for weeks. Then, he wrote 4 lines on the blackboard.


Define the Model
Bound the Model
Calculate the Equations of State
Calculate the Gibbs Free Energy

As he lectured on, he put stars in front of the lines as he spoke :

  • Define the Model
  • Bound the Model
  • Calculate the Equations of State
  • Calculate the Gibbs Free Energy
Then, he retraced and bolded each line:
  • Define the Model
  • Bound the Model
  • Calculate the Equations of State
  • Calculate the Gibbs Free Energy
Anyway, he went through about 3 sticks of chalk in that hour, but I still remember it after 46 years. Of course, there was a period when I used it every day.  I modified it to;


Define the Model

Bound the Model

Calculate the Equations of State

Calculate the Gibbs Free Energy

Calculate Fate and Transport

Calculate Biological Interactions and Transformations

Calculate Dose and Toxicology

Calculate Affected Populations

Calculate total damage to humans and infrastructure


After that, I could walk around any Bechtel office at night, in my stocking feet, and the only comment was an awed, "You worked for SN!"


Climate science does not bother with the whole list these days. see for example
New use of global warming potentials to compare cumulative and short-lived climate pollutants by
Myles R. Allen, Jan S. Fuglestvedt, Keith P. Shine, Andy Reisinger, Raymond T. PierrehumbertPiers M. Forster Nature Climate Change (2016) doi:10.1038/nclimate2998  Published online 02 May 2016

They do not define the model; not for SLCPs, GWPs or GTPs. They do not bound the model. They excluded oceans, wetlands, and all of their contained biology, but there is no formal boundary. Since they are working in a single phase, they do not bother to calculate biological transformations. They do not bother to calculate equilibriums between aqueous and vapor phases, or between aqueous and solid phase (e.g., clathrate).  Bad chemistry! On the other hand, much of the climate system is not at equilibrium!  On the other hand, climate science does consider the atmosphere to be "well mixed" so there is an assumption that the system is not too far from 
equilibrium.  Planetary motion both mixes the system, and keeps the system out of equilibrium.

This lack of lack of modeling rigor has allowed the IPCC to consistently understated the risk and extent of climate change. I say the current under-statement is about 38% - with interest compounded second by second.  They invoke some kind of magical "half-life" for SLCPs but do not define the reaction, its mechanism, its state, or its Gibbs Energy.


One point is how they treat CH4 as a greenhouse gas. In the short term, methane is ~86 times powerful than CO2 as a greenhouse gas.  However, CH4 is more reactive and has a much shorter lifespan in the atmosphere than CO2, or does it? Does methane deserve to be given a global warming potential (GWP) of only 24 for climate modeling?

In the atmosphere, methane is oxidized by OH- and Cl- radicals, while CO2 is not. On the other hand, CO2 is converted by plants and algae into O2 plus biomass. In aqueous environments, CH4 can be produced and metabolized by various bacteria, at material flows much greater than the “rate limited” atmospheric oxidation process.  On the other hand, CO2 is more soluble than CH4 in water, and thus CO2 can disappear out of the atmosphere into the oceans (and then reappear.) Thus, the actual amount of CO2 and CH4  in the biosphere is controlled by biological processes that respond greatly to temperature, oxygen concentration, and other environmental factors.  However, the IPCC tends to be dominated by Atmospheric Chemists and Computer Modelers that accord Biologists second class status.  In contrast, I tend to think in the terms of equilibriums controlled by Equations of State, Gibbs Energy,  and most importantly -- Biology. And everything published by the IPCC is reviewed by lawyers and governments that desire to avoid public panic.

If we consider solubility, then when equal pulses of CO2 and CH4 are added to the atmosphere, much of the CO2 will go into the oceans, so the actual near term effect of  the residue of CH4 pulse in the atmosphere is on the close order of 260 times more powerful than the  actual near term effect of the residue of the CO2 pulse in the atmosphere.  

And, as we consider sequestration, we much remember that both CH4 and CO2 are in the oceans, and will come out as the partial pressure of these gases in the atmosphere decreases. As we plan to take greenhouse gases out of the atmosphere, we need to plan for the gas that will come out the oceans. Or, the biological processes in the oceans can convert either or both gases into biomass, thereby reducing their concentration(s) in the oceans, and causing the gas(es) to move from the atmosphere into the ocean. The ocean may be the easy path to sequestering carbon out of the atmosphere.

If we look at the observed CH4 levels in the atmosphere (http://www.esrl.noaa.gov/gmd/ccgg/trends_ch4/#global_data) we see that the CH4 concentration in the atmosphere goes up, not down as would be expected with a defined half-life on the order of 10 years. Looking at the CH4 bump in the atmosphere after the oil well fires of 1991, there is a decline that looks to my eye like a higher partial pressure in the atmosphere coming into equilibrium with the dissolved CH4 in the oceans/wetlands.  And, the bump in 1997, looks like higher ocean temperatures from El Nino reducing the solubility of CH4 in the oceans, so CH4 partitions into the atmosphere, then returns to the oceans as cold, deep water is exposed.

Part of the problem here is that many Environmental Scientists took general chemistry and were taught that CH4 is “not soluble” in water.  In fact, CH4 is soluble in water at a few parts per thousand. Thus, in the context of CH4 at a few parts per million in the atmosphere, the oceans can and do hold a great deal of dissolved CH4 in solution, and the bacteria in the oceans can produce a lot of CH4 as O2 concentrations diminish and temperatures rise. (in the same way, green plants algae and bacteria can reduce large amounts of CO2 (e.g., CO2=> biomass + O2) , but CO2 reduction is discounted by the IPCC.)

At the surface, CH4 in the ocean is in equilibrium with the atmosphere (resulting in a very small flux across the phase boundary). In deeper colder water, the partial pressure of CH4 in the water is in equilibrium with the clathrates at the sea floor.  As the world’s waters warm,  CH4 will move from the surface waters into the atmosphere, and  clathrates will dissolve into the bottom waters.  (Or, as we have started to observe in the last 20 years, even release CH4 into the atmosphere.)

Anyway, all of this means that we have to model CH4 in the atmosphere as if the current concentration of  CH4 will be in the atmosphere for at least 20 years.  Thus, the CH4 as equivalent CO2 is  ~160 CO2e.  Add in the real CO2 (405 ppmv), and greenhouse forcing is  currently 565 CO2e, yielding a forcing of ~ 3.6 W/m^2.  Given that permafrost and clathrates have already warmed enough to start melting/decomposing, a climate sensitivity number as high as 3 seems justified. That would indicate an expected temperature from global warming at current conditions on the close order of 10.8C.  That is well above IPCC estimates. And, it is now! Waters that were in the tropics 50 years ago, are releasing heat in the Arctic now.

Fifty years ago, the forcing was only 2.6 W/m^2 (assuming CH4 GWP = 86), while today, the tropic waters are forced at 3.6 W/m^2, and waters that are in the tropics now,  will be releasing that (38% more) heat in the Arctic in 50 years.

Some would object that the forcing formula is standardized for a period of 100 years.  I would counter that with 560+ CO2e, over the next 20 years enough permafrost and clathrates will decompose to raise greenhouse forcing to a much higher level. Over the longer term, expecting the clathrates in the bottom of the ocean to remain solid is like expecting the ice in your tea at a Houston, Texas BBQ party to stay solid. As the tea warms, the ice will melt.  As the oceans warm, the clathrates will decompose. If we are seeing large scale clathrate decomposition 50 years, then there will be a great deal more CH4 in the atmosphere in the second half of the 100 year period, and this kind of senario is simply not recognized by the IPCC.

A corollary is that  polar ice will “melt” faster than the current generation of models predict.  I suggest that the older ice flow models using Navier-Stokes/conservation of momentum equations, miss the point that -- ice near its melting point becomes highly discontinuous.  In particular, ice fractures can concentrate stress from large volumes of ice into melt energy in tiny volumes at the propagating edge of  fractures.  Likewise, moulins and hydro-fracture processes disrupt “momentum” ice flow models. Any model of ice at its melting point expressed in differential equations expressed in differential equations will fail chaotically at the discontinuities. And, we have reached the point where there is liquid water at both the top and bottom of many ice structures meaning that top and bottom surfaces are at their melting point/ discontinuities. Where there are moulins and hydrofractrue events, the discontinuities extend through the ice from top to bottom, and the ice models must fail.  Ice sheets do not have to melt in place.  Now we know, that most ice can “fall” into fjords or the ocean and float away.  All that it takes is enough warming to weaken the ice so that it fails under the stresses imposed by the weight of the ice. My best guess on sea level rise is meters in decades.  NOAA has started to report similar estimates. (E.g., https://www.kcet.org/redefine/sea-level-rise-could-come-much-sooner-than-you-think , http://www.insurancejournal.com/news/national/2016/04/12/405089.htm , )

The sea water advecting heat into today’s Arctic was warming in the tropics, decades ago.  Most of the heat in the biosphere is in the oceans, but most climate scientists look at the temperature of the atmosphere for a reading on the state of the climate.  This disregards the heat that goes into warming and melting ice.  This disregards the heat that goes into the oceans.

There is a significant lag time in climate systems.  We could stop burning fossil fuels today, and it would be 50 years before warming stabilized. We could stop burning fossil fuels today, and it would be centuries before the sea floor clathrate and atmospheric methane inventories stabilized. If oxygen levels in the oceans decline, then the biomass in the oceans will be converted to methane, and the equilibrium value for methane in the atmosphere could be high.  These are issues not addressed by IPCC models.

I did computer modeling for Dr. Jay Forrester for the Club of Rome Report that became Limits to Growth by Meadows et al (1972).  Much later, I wrote the Bechtel Risk Management Manual as we considered the full range of very large nuclear facility and hazardous waste site issues.  We were trying to price the decontamination, demolition, and waste disposal projects being offered to us.  For a long time, I kept a list of the 300 worst things that could happen on large, long term projects, such as the Hanford Waste Repository with its 100,000-year design-life, and potential to contaminate the Columbia River with hazardous and radioactive materials.  Along the way, I worked on a number of the worst hazardous waste sites in the world, and did fate and transport analysis of how bad stuff could affect populations; now, in the future, and in the deep future.

Risk actually has 3 components; Likelihood of the event,  intensity or damage from the event, and the likely timing of the event.  Life is a sequence of risks, and sometimes resources must be allocated sequentially. For example, the sun will die, causing great damage to Earth Bio systems, but that is in the deep future, and we should address other risks first.  Super volcanos and large asteroids can inflict great damage, and are very likely risks in a time scale of a million years, but AGW is a similar risk in the time frame of a few of decades. We should address AGW first, so we will be around to worry about super volcanoes as they will  appear.

At this time, the likelihood of AGW is near certain. (my estimate is 99.9999999%)  Given the  current concentrations of greenhouse gases in the atmosphere and oceans, likely warming is almost certainly catastrophic for most animals over 4” in length.  We have already seen more than a degree of AGW, which means that water vapor in the atmosphere has increased and is now acting as a greenhouse gas. This will warm the oceans faster, lowering the solubility of CH4 and CO2 in the oceans, and increasing the amount of greenhouse gases in the atmosphere. Thus, AGW is a global risk, a catastrophic risk, a near certainty, and a very urgent risk.

In addition, AGW carries with it a spectrum of follow-on effects of unknown impact and unknown level of warming  required to trigger the impact. These include spread of diseases such as  Lyme and Zika.  Changes in climate faster than agriculture can adapt resulting in large scale crop failures (e.g., drought) .  Loss of important ecosystems as a result of migration or extinction of keystone species.  (Ghost forests in California) Weather that routinely damages engineered infrastructure.  Weather that damages important resources. Weather that kills national populations (https://en.wikipedia.org/wiki/2010_Northern_Hemisphere_summer_heat_waves,  https://en.wikipedia.org/wiki/2011_North_American_heat_wave , https://en.wikipedia.org/wiki/Summer_2012_North_American_heat_wave ,  https://en.wikipedia.org/wiki/2013_heatwave_in_Ireland_and_the_United_Kingdom   , http://www.climatecentral.org/news/australia-2014-heat-wave-picks-up-where-2013-left-off-16938 ,  https://www.climate.gov/news-features/event-tracker/india-heat-wave-kills-thousands ) have become routine. I assert that AGW and resulting drought beginning circa 2006  was an important factor in the Syrian situation.  The drought in Thailand and India looks much like the recent droughts in Texas and California.

Weather is a heat engine, and heat is fungible. All heat affects all weather.  All weather is affected by all heat.  Attempts at attribution are silly.  The heat from AGW is in the system, and is affecting all weather.  It is in the nature of greenhouse gases that as they heat the lower atmosphere, they cool the upper atmosphere, making the atmosphere less stable and much more prone to violent weather.  And, cold air above warm moist air makes large snow and hail storms more likely. 

It is very like the risk faced by the Elephant's Child in Kipling’s story after the Crocodile's musky, tusky mouth caught the Elephant's Child by his little nose. At this time we should take the Bi-Coloured-Python-Rock-Snake’s advice, and immediately and instantly, pull as hard as ever we can, to avoid being jerked into yonder limpid stream (by which I mean AGW) before we can say Jack Robinson.  Like the Elephant's Child, we have been reckless and na├»ve.   We may survive, but like the Elephant's Child, the effort required will stretch us, and change our outlook in every way. 

http://www.boop.org/jan/justso/elephant.htm
cumulative and short-lived climate pollutants
Myles R. Allen
1,2
*
, Jan S. Fuglestvedt
3
, Keith P. Shine
4
, Andy Reisinger
5
, Raymond T. Pierrehumbert
2
and Piers M. Forster

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