Not Really Physics - Climate Changing Botany

So much of Climate Change is just accounting and just about every thing NOT physics that it is frustrating for many.  I started this blog because I found an accounting problem with the Earth Energy Budget.  There are also problems with the Carbon Budget so large they make the surface temperature squabble irrelevant.  I hit on one potential biological situation that could pretty much erase fossil fuel emissions, termites and wood destroying organisms.  This one is more in line with Dyson's carbon eating trees.

Trees and forests in general are a favorite because it is obvious they have huge amounts of mass above ground.  Most trees though aren't that great at building below ground carbon.  Since trees rule the roost so to speak, they are first in line for water and nutrients so tropical forests have extremely poor soil.  The trees in the tropics may have only 10% of their total mass underground and since insects thrive in the tropics, leaf litter is pretty quickly consumed.  A tropical forest can reason a carbon neutral state just because of a weak drought or shift in wind patterns that reduce wind blown nutrients, like Saharan dust fertilizing the Amazon.

Plants that are extremely drought tolerant tend to have huge root systems that allow them to survive drought and heavy grazing.  On the US great plains, original homesteaders build crude houses with sod that was extremely stable because of drought tolerant grass root systems.  The Sahel is greening because native shrubs and trees had extensive root systems which only required a little rain or a little less grazing to string back to life. For whatever reason, soil carbon estimates do not include deeper rooted (> 1 meter) plants that where likely native prior to industrialization.  Because of that, soil carbon estimates are between 10% to 50% low (lateral carbon runoff is particularly difficult to estimate).

Botanists, didn't miss that error.  "Breeding crop plants with deep roots: their role in sustainable carbon, nutrient and water sequestration" specifically addresses the issue of breeding or genetically engineering deeper rooted drought tolerant plants.  The advantages of more drought tolerant plants is obvious but the carbon sequestration isn't discussed often.  In fact, if you mention how conservation farming stores soil carbon, even most of the experts underestimate the potential impact.  For example, replanting tropical deforestation is consider to be worth 100 tons of carbon per hectare at a maximum.  Starting the reforestation with drought tolerant plants could increase that by 40% and more likely recreate the original start of the tropical forests.

A number of grand tropical plantation plans died because the soil just wasn't ready for the trees, especially in monoculture. Bananas may be on the way to extinction because of monoculture planting and a mutating fungus.  The fungus remains in the soil so once infected that acreage will never produce bananas again without expensive soil fumigation. So rebuilding soils without causing some future damage isn't easy.  Some of the better results came from giving up and just letting "nature" take over.  Helping nature along with a variety of deep rooting native species seems to be worth a shot.

Biofuel advocates and land owners that consider productive land in the normal sense to be carbon "neutral" might need to consider carbon optimal from a more realistic perspective.  Coal use for power plants accounts for about 25% of emissions with the average coal power plant still only 36% efficient.  Adding secondary processes to coal power production like local heating or desalination/purification can increase efficiency to over 80% in ideal cases.  At the same time, using resources generated by the thermal power plants to restore depleted and abused soils would make the coal/soil interaction a net carbon sink.

While nuclear or renewables could be used to help restore soils, coal's carbon content and trace elements  Coal flyash for example  may not be recommended for food crops supplement, but in reforestation efforts the flora could make use of the trace elements and help filter out unwanted heavy metals.  Instead of attempting to sequester CO2, fertilizer production as a secondary process could be used to increase the growth rate of reforestation projects, which would also sequester carbon.  

There is a lot of interesting research in land reclamation being marginalized by advocates of urgent actions "they" approve of.

Forcing a Forcing Proxy

This is one of those "if only" kind of posts.  If only, climate science wasn't so set in its ways, this could be a great idea.  A Teleconnection, or a particular geographical location that has a high correlation with "global temperature anomaly" is a tool used and maybe abused by climate science.  For example if the wiggles in a group of tree rings from California happen to correlate well with what is assumed to be an accurate interpretation of what "global" temperature anomaly wiggles are likely to be, the California tree rings get more consideration than some place else.

Since we are currently in one of the large El Nino event influences and El Nino has a pretty good correlation with warming, the higher than normal rainfall you would expect in California should be a pretty good indication of past climate.  The real key isn't California, it is El Nino and the ENSO cycle.  So you could just blow off California trees and use any trees, sediments or anything else that is a proxy for ENSO.  Since the Indo-Pacific Warm Pool (IPWP) is the hot side of the El Nino region, it is just as good as anything else.  This is why Oppo et al. and team young guns devote so much time to the IPWP paleoclimate and even try to estimate "global" ocean heat uptake over the past few thousand years.

The young gun's data differs than some, i.e. Michael Mann and the old farts, most likely because ocean paleo has a more reliable range of temperature dependence than trees that prefer a Goldilocks range of temperature, moisture, nutrients and pests.  Mann though had a head start and proclaimed California trees the cat's ass before the young guns were out of diapers.

The much publicized "divergence" problem is the Goldilocks tendency of trees most likely.  That doesn't make tree ring useless, they were originally proxies for rainfall and that is a big part of the El Nino signal, so they have a reason to be included in the debate.

The neat thing about ocean paleo is that there is a real temperature involved.  Instead of just matching wiggles you have temperature and wiggles.  When you have temperature you have a rough idea of the effective radiant forcing.  There is more involved, but radiant forcing as used by Climate Science is a large percentage of the combined, latent, convective and radiant reality.  Since the ocean rate of heat uptake tends to control or regulate temperature, the young  guns can use absolute temperature below the surface which doesn't include latent and much convective to get a reasonable indication of heat uptake and the real energy involved.  Since SST and ocean heat uptake correlated extremely well, they would also correlate reasonably well with the forcing required to change the rate of heat uptake.  Since the biggest difference between the young guns and da Mann are "pre-industrial", there is a pretty good bit of money riding on the winners.

Neglecting uncertainty for the moment (hey, at least I admit it), the young guns IPWP reconstruction indicates there has been about 8 Wm-2 of radiant forcing change since 1700 AD.  Combined "global" forcing change is estimated to be in the 4 Wm-2 range or about half of what this rough proxy indicates.  There is a big kerfuffle over this half issue.  Some of the forcing has to be caused by man and since fossil fuels are easy to estimate, they are to no brainer "cause".

I happen to be a bit of a rebel and think there is more to the story, land abuse, which should mean that warming started well before fossil fuel abuse.  There are lots and lots of "potential" land abuse factors that are close to impossible to sort out. You just need one to provide a hook, but if you pick the wrong one, the hook will end up in your butt.  Use bunches of potential land abuse factors and the simplifying simpletons will eviscerate you - gut you like a fish. :)  That sucks, because the real world is complex, but there are a few hooks that are more interesting than others.  Formosan Subterranean Termites may be a pretty good hook.  More interesting meaning likely more significant and easier to sort out.

Subterranean termites are a new world invasive species.  Since they are biological, they have a nice exponential growth curve until they reach a population peak.  The termites eat woody stuff which releases CO2 and CH4 from what was a "natural" carbon sink, decreasing the efficiency of that sink.  If you are a bit anal about sinks and sources versus natural and anthro, you might have to consider that a natural mechanism in an unnatural environment for them would pretty much have to be unnatural.  "Globally" all the natural sinks would be still sinking but you have half a hemisphere that isn't hitting on all eight.

There are still a lot more anthro land abuse impacts that would have an exponential curve, but the termites might be testable.  A systematic invasive termite eradication program would at least stop the population growth of termites allowing the sink to to operate more efficiently.  There are also a number of invasive pests that contribute to more woody matter for the termites to munch on that could be targeted.  Of course none of this will be taken seriously as long as demon coal and fossil fuels get all the press, but increasing land carbon uptake by a fraction of a percent would offset nearly all of the fossil fuel emissions.  I may toy with this approach in the future.

Equilibrium Climate Sensitivity?

Been enjoying my break from major blogging.  During that break not much has changed though there are a few interesting shifts by some to my perspective.  The being that the general thermodynamic approaches used are not really fit for purpose.

A large part of that is Equilibrium which is a bit of a stretch for a planetary scale open system.  The average ocean temperature ultimately will control what degree of equilibrium is reached and the time scales aren't really well known.  Based on the current estimated rate of heat uptake, current estimate of "average" temperature and the estimate of total ocean volume it should be over 300 years before a 1 degree rise could reach "equilibrium".  Add to that what should be considered "normal" or "pre-industrial" and the use of equilibrium can get abused.

There has even been some mention of how estimates of solar energy estimates could be tweaked.  For the oceans the solar pond approach which considers the changing angle of incidence is what I would think the way to go and is included in some models but the overly simplistic TSI/4 is still used in most conversations instead of the more appropriate TSI/pi().  Since various layers of the ocean and atmosphere absorb solar energy and the atmosphere tends to bend light, the smaller imbalance becomes the greater the error simplifying assumptions will produce.

Just using crude estimates, the oceans should have an imbalance on the order of 0.2 Wm-2 just because of the current timing of the southern hemisphere dominate solar precessional cycle.  That alone could be a third of the current imbalance leaving the anthropogenic portion of the imbalance in the 0.4 Wm-2 range or about 40% of original estimates.

Somewhat surprisingly, the neutral to negative CO2 forcing in the Antarctic and really any extremely cold region, has finally gotten some peer reviewed press only 5 short years after my picking on the gang at Real Climate about the issue.  My, how climate science progress flies.

As I have mentioned, the poles are the ultimate heat sink from a thermo perspective with the stability of the polar vortex being part of the relief mechanism for excess warming.  A single major breakdown of a polar vortex can release as much energy as the oceans can uptake in a year.  That shouldn't stop warming, but it will delay the rate of uptake on that unknowable path to a possibly unattainable equilibrium.

All of this brings me to the conclusion that a bunch of educated guesses are likely much better than any number of expensive modeling attempts.  Once you consider that, 1.6 C per doubling with about half of that never to be realized 0.8C +/-0.3C is likely with a slight chance of 1.6C +/-0.5 C if by some remarkable accident "climate" really has no variability on longer time scales.

Also it is interesting that land use impacts are getting a bit more respect.  While the radiant impact of land use change is small, changes in soil carbon and moisture are a bit more important.  Possibly 1/3 of the CO2 in the atmosphere is related to land use and up to 1/2 if you consider the reduction in carbon uptake had trees and such been used for something other than food and fuel.

On the food to fuel front, there are a few interesting complex economics papers stating what should have been obvious about the impact on food prices which tends to stress all economics leading people to start doing things like pondering the end of days and global domination.  Even the poor invasive honey bee is over stressed trying to pollinate all those healthy almond trees in drought stricken California while butterfly and bee fans are calling for more pasture land to stave off possible extinctions.  GMO crops are of course the designated villain since no health food nut would ever blame almond mono-culture.

Some how, contaminated water supplies have avoided the Climate Change blame game as northern union supporting cities rapidly replace failing iron and lead water mains with iron and copper water mains instead of non-conductive and mainly non-union PVC and HPDE water mains like those ignorant red states are doing.  I doubt that will last very long since winter freeze/thaws tend to signal the beginning of water main break season in the far North and everything weather is of course "Climate Change" caused.

Some more Basic Thermo stuff

I have been on break and loving it.  Progress in climate change is about like watching paint dry anyway, but there is a bit of an interesting debate over the usefulness of simple one and two dimension models versus the big honking coupled climate models.

One of the biggest mistakes made is the oceans are the heat sink concept.  The minimum temperature of the oceans is about -2 C or the freezing point of average salt ice and the rough maximum temperature of the oceans is 30 C degrees.  There are fluctuations up to around 32 C but 30 C is a bit more common.  If the oceans are a heat sink the maximum Carnot efficiency is about 9% meaning 91% of heat would be lost to space somewhere along the line.  If you tried "average" temperature of the Earth, the efficiency drops a little bit to about 6% and average ocean to average surface reduces that a bit more.  If the rate of ocean heat uptake is 0.6 Wm-2 and the uptake efficiency is 9%, that would put forcing in the 6.67 Wm-2 range.

Since this is super simple model there are a lot of questions, but it implies approximately 1/3 of ocean heat uptake isn't related to atmospheric forcing of about 4 Wm-2.  Since nearly all of the ocean heat uptake is in the southern hemisphere, this indicates to me that about 1/3 of warming of the oceans is related to long term recovery and the current solar precessional orbit position.

Along with that, most of the warming in the atmosphere is in the northern hemisphere which happens to have the warmest ocean surface temperatures.  Having the warmest SST and the least ocean heat uptake rate indicates that a simple Carnot efficient model is very limited.  However, since the northern hemisphere lacks a circumpolar current to increase heat uptake efficiency and Carnot is a maximum, nearly zero efficiency as opposed to a low 9% efficiency isn't inconsistent with the model. Anything over 9% would be obviously wrong.

I have used Carnot efficiency models about as much as they can be useful and they indicate lower climate sensitivity and larger uncertainty than most estimates I have seen.  Even with the uncertainty, the different uptake rates of the two hemispheres relative to the actual surface temperatures isn't consistent with northern hemisphere aerosols limiting surface temperature rise by very much.  "Globally" it could explain the 1/3 difference, but not by hemispherical.