Tuesday, April 23, 2019

CO2 is garbage not plant food


Is there a bunny so sheltered that he or she has not seen myriad repetitions of denial starting with CO2 is plant food?

Eli is a patient bunny, but has decided to take up arms against this nonsense.

CO2 is garbage.  It is recycled by photosynthesis using renewable solar energy

Go forth and spread the word.  It annoys the hell out of those in denial about how people are changing the climate for the worse.  Even better it is accurate.

The bleats you will earn are your blessings.

Thursday, April 18, 2019

Yes, Eli has been on sabbatical, but he really has been thinking of the bunnies, especially with Easter coming up.  Well, sometimes it just gets hard to think of something new and interesting and life, or at least Twitter, has become a series of re-runs where all that is needed is a link to some old Rabett Run post (there are some goodies there the Bunny will tell you:).

In any case there has been recent discussion about a chart posted by the Lawrence Livermore Lab folk about US Energy consumption and copied to TwitterSeveral are trying to use this as an argument against fossil fuels pointing to the fact that rejected energy is a large part of electricity generation and more.


This is tied together with a basic confusion first discussed by RayP on Real Climate, that the problem with fossil fuels is not the rejected energy, but the fact that the greenhouse gas emissions remain in the atmosphere and slow the emission of heat to space over centuries.  In a letter to Steve Levitt, Ray dispensed with Nathan Myhrvold's argument that
. . . in effect, that it was pointless to try to solve global warming by building solar cells, because they are black and absorb all the solar energy that hits them, but convert only some 12% to electricity while radiating the rest as heat, warming the planet. Now, maybe you were dazzled by Mr Myhrvold’s brilliance, but don’t we try to teach our students to think for themselves? Let’s go through the arithmetic step by step and see how it comes out. It’s not hard.
Interested or, as in the case of Eli, those with the dread forgetting disease, can follow Ray through the calculation, but the point is that all energy eventually (may take the age of the universe, but eventually) degrades to heat, but some of it can be used in the meantime to do work (move things non-randomly, including electrons).

The reason that fossil fuels are heating the Earth is not that they produce heat as well as work, but that their CO2 emissions continue to increase the amount of thermal energy in the atmosphere, on the surface and in the oceans, over centuries.

Sunlight heats the Earth and is degraded to heat which radiates into space by IR emissions from the surface and the atmosphere.  Increasing the amount of greenhouse gases in the atmosphere slows the rate of radiation so that the Earth has to warm, increasing the rate of radiation to return the system to balance.  Energy added on the surface by fossil fuel combustion or nuclear energy or wind or solar, or whatever is soon degraded to thermal energy and radiated to space.  It's a small one time charge.

The ratio between the work, W that can be done and the energy input U, W/U is the efficiency, and the heat produced is Q. 

Thermodynamics sets the upper limit to efficiency.  Engineering sets the actual limit.  It turns out that renewables like wind and solar are not very efficient, but that the heat that they generate in creating work does not lead to a continual warming of the system over centuries.  The same is true for heat generated in fossil fuel combustion, but, as RayP pointed out a decade ago, that is irrelevant, because the CO2 produced in fossil fuel combustion DOES heat the Earth for centuries.

That being said, it's good to be efficient.  For one thing, it costs less over the long run in the building, operation and maintenance of stuff.  Also, rejected heat is local, which can be both good and bad, depending if you can use the heat for other things like industrial processes, or heating the home.  That gets deep into the weeds and Eli will leave it there

Friday, April 05, 2019

The clip that Republicans will play if Biden's the nominee - "Mr. President, my suggestion is don't go"

Unfortunately I don't see an embed option, but if he's nominated, then a shortened clip of this CNN video will get rotated heavily next year, starting about 55 seconds in, where Biden says his response to question of whether to attack the bin Laden compound was "Mr. President, my suggestion is don't go".

Expect to see that heavily played if he's the nominee. Also, if Republicans want him to be the nominee, I expect it won't be played at all by the Republican elite prior to the nomination, although they can't control everybody on their side.

They will cut off the video right before he adds "there are two more things you should do first." The Dems can point that out; it won't help them very much.

He can also point out how he backtracked in 2015 as he was considering running against Clinton, and announced the secret and contradictory advice he supposedly later gave the president:



 I don't think that will help him that much and may actually hurt him.

More here at The Atlantic on the questionable quality of his foreign policy advice in general.

Having said that, if he's the nominee he will be light years better than Trump, Pence, or whatever other disgrace the Republicans choose, and I'll give money and time to get Biden elected.

Tuesday, March 26, 2019

Putting down a marker on eating the ICE infrastructure away

Been looking for data like this for a long time:






Turns out that California Energy Commission has gasoline data, lots of gasoline data. I downloaded and edited the data above.

I've argued since 2013 that as EVs start taking up significant market share, the gas station and repair infrastructure for internal combustion engines will start to shrink and become less convenient. A similar-but-distinguishable process will happen with increasing ICE mileage, but that process stabilizes because even high mileage ICE vehicles still need gas and will pay enough to stabilize the number of stations. As EVs eat into the ICE infrastructure, the ICE market just gets less convenient and the shift to EVs accelerates in a virtuous feedback.

The effect will be especially strong when people consciously notice the ICE infrastructure is getting less convenient, but that's not required. And I fully admit the more important factor, for now, is EVs becoming more convenient. Still, a choice of EV versus ICE turns in part on the relative convenience of the choice, and increasing inconvenience for ICE will have an increasing effect.

Oslo would be the best place to test this, but I can't find their data. San Francisco Bay Area isn't a bad alternative. This doesn't constitute proof yet - 2016 was the highest year in the dataset, and it would be bold to claim the 2017 decline is from EV share of the fleet mileage traveled, but let's watch this space.

Tuesday, March 12, 2019

A thing of beauty

Sabine Hossenfelder's new book, Lost in Math:  How Beauty Leads Physics Astray is stirring up quite a stir with multiple reviews.  Hossenfelder has recently stuck her oar into the question about whether a new supercollider should be built as a follow-on to CERN.

The just-look-argument is of course well and fine. But, as I have pointed out many times before, the same just-look-argument can be made for any other new experiment in the foundations of physics. It therefore does not explain why a larger particle collider in particular is a good investment. Indeed, the opposite is the case: There are less costly experiments for which we have good reasons, such as measuring more precisely the properties of dark matter or probing the weak field regime of quantum gravity.
Eli got into this a little bit on Twitter
but the issue of beauty in physics, in science in general, what is worth doing, at least to Eli is of interest.  About a month ago the Rabett in a comment to Hossenfelder thought that beauty in physics was a matter of being terse, spare simple.  She really did not like that, and after all, who is Eli.  Reading the New Yorker this week a rather better description appeared in James Marcus' memorial to his father, a bioscientist, who died a difficult death.
Later, after his death, one of his colleagues noted that my father "believed that beauty would save the world".  My father would never have said that about himself.  Yet it was true, if you understood beauty to encompass not only ecstasy but precision, rigor a relish for the tiniest (literally microscopic) details. And it was true about me, too. We were a religious sect consisting of two people, and now half the congregation was gone. There would be no closure, no healing. I would simply adjust myself to a new and severely depleted reality. The world would come to an end, as it always does, one world at a time.

Saturday, March 09, 2019

Paul Campos on dual loyalties, Israel and Omar

He sez:

....This whole sordid mess is a product of, among other things, the insidious idea that it’s undesirable for people to have “dual loyalties” in the context of their relationships to nation-states.  This idea is obviously absurd if stated as a straightforward proposition, which is why it almost never is.

People have multiple loyalties in every other aspect of their lives, so why wouldn’t or shouldn’t they in the context of their relationships with nations?  I’m not Jewish, but I think it’s completely ridiculous to criticize American Jews for feeling various levels of affection toward, passion for, and loyalty to, the state of Israel....

The accusation of dual loyalty, in other words, is based on a completely bogus theory of both human psychology and political morality.  And yes, I realize “dual loyalty” is a classic anti-Semitic trope, but that accusation only has bite because of a perverted concept of patriotism, which requires loyalty to the present government of the nation of which one is a citizen to always trump every other consideration.  In other words, “dual loyalty” is only bad per se if one accepts the essentially fascist concept of loyalty to a single nation state as the first duty of every citizen of the State.

Read the whole, etc. While I think he has good points, esp about fetishization of the state, the acknowledgment that we have biases doesn't remove the obligation to confront and control those biases, to the extent we can and acknowledging our limits. The issue runs both ways - anti-Semitism has woken from near death with the rise of conservative nationalism, while the left has an obvious point at how biased American foreign policy is toward Israeli right-wing government positions and against Palestinians.

My great-grandparents and their parents emigrated from Austria-Hungary to the US in 1910. My understanding is that German-Americans disproportionately opposed American entry into World War I. It's lost to time whether my relatives took part in those politics, but the German-American bias is worth acknowledging. It's not necessarily wrong - maybe we'd have fewer wars if people cared about the lives of family relatives in the opposing military trench. It does however complicate things.

I hope we can get a somewhat-more balanced perspective on Israel (given everything global, I favor a somewhat pro-Israel stance for the US) while confronting anti-Semitism and other biases wherever they arise.

Tuesday, February 26, 2019

The Impossible Burger isn't good enough. The Beyond Burger is better (also, Beyond Sausage)

So I liked the hype, but after five or six attempts, I'm just not sold on the Impossible Burger. Maybe I need to try it well done, but every patty I've had ends up a thin gooey red mess in the center. I'm guessing it might be okay as a crumbled addition to a entree, like in omelettes or tacos, but not as a burger.

I've blogged before about Beyond Burger as a vegetarian alternative, and I think it's better. No clue why it sits in the grocery stores while Impossible Burgers command a premium at restaurants. Well, one clue - my wife can't stand coconuts, and it has a mild coconut smell and taste..

Anyway, not a burger substitute but far better than any vegetarian dogs I've had is Beyond Sausage, now showing up in my Safeway store. No coconut smell or taste btw. It wasn't so great on an electric grill, but sliced and fried up on a stove, it easily matches regular sausage.

Convenience marches on. Contra David Roberts, I think to the extent environmentally aware people can easily do something more, we should do so.

Sunday, February 24, 2019

Please please please not Bernie or Biden (also, think carefully about Klobuchar)

There are ten thousand horrifying gifts regarding Trump's manifest unfitness for office. High up in the ranks of unfitness, because it's objective, is his age as the oldest president ever to assume office tied with his concealment of his health and mental health status. Why then would Democrats choose to nominate someone who is even older? Bernie and Biden are four and three years older than Trump respectively, and at that age that difference counts.

It's easy for me to say this in part because I'm not big fan of either men. Elizabeth Warren is three years younger than Trump. She's also at a point where her age counts somewhat against her - not against Trump, it's in her favor, but against the real chance that Mike Pence (10 years younger) or someone else will be the Republican candidate.

The first main point is that there's a wide range of Dems to choose from - why give up a huge advantage by choosing Biden or Bernie? Warren's age counts moderately against her too in my opinion but not as a disqualifying blow.

A similar analysis relates to Klobuchar - the current evidence seems to pretty closely tilt her from demanding to abusive. I'm not sure it's disqualifying yet, and apparently there's some smoke surrounding Bernie too and other male candidates that should be investigated, but we Democrats have the luxury of a wide range of choices. We can be picky.

The second main point, maybe one for another post, is that Trump's awfulness doesn't guarantee he's going to lose. The most important thing is to beat him, not to get the Democratic candidate that exactly matches our personal political preferences. Time to be picky regarding some political disadvantages among the candidates.

Last point - all Dem candidates, but especially the older ones, should undergo public reviews of their physical and mental health fitness for office. It is now a great time to establish this precedent, one that works against Trump and will be helpful in future elections.


UPDATE: For a contrary opinion, read Everett's multi-part diatribe against my evident ageism and stupidity in the comments. YMMV. FWIW, I'm hitting the age at which I'm just starting to get concerned about ageism as my career progresses, so I obviously don't like ageism. OTOH, despite Bernie's conclusory statement against ageism, I bet that if forced to do it, he'd acknowledge that if a candidate were 10 or 20 years older than him, that candidate's age should be considered as a factor. So should Bernie's.

There he goes again v.93 p.1221....


On his last visit, but before leaving
Ethon described a wonderful piece of misdirection from our friend in Colorado, who asks for advice on improving this:

No emissions reduction policy currently under discussion – from changes in personal behavior to those proposed under the Framework Convention on Climate Change – even if successfully implemented will have a discernible effect on the global climate system for at least 50 years.
and points to a statement
NCAR's Jim Hurrell observes, "... it should be recognized that mitigation actions taken now mainly have benefits 50 years and beyond now."
as support for the "scientific accuracy of the first sentence.

Now Ms. Rabett Sr. was school teacher and the first thing Eli noted was the difference between "mainly have benefits" and "no emisions policy will have a discernible effect on the global climate system".

So at a minimum Hurrell says that MOST OF THE BENEFIT will come later, but there will be some earlier than 50 years. He who must not be named twists this into NO DISCERNIBLE EFFECT. Several of the comments point out that policies implimented today will take time to establish, economic systems do not stop on a dime, and that even after the policies are implimented it will take time for the climate system to respond. However, let us look and see if

Monday, February 18, 2019

CA HSR, RIP (kind of)

So just as high speed rail gets a political lift via the Green New Deal, the one active effort bites the dust in California. Read the link though, it's not entirely dead - Newsom committed to a strange little stretch in Central Valley from Merced to Bakersfield that's already partly constructed, and put off the rest for another (undefined) time. Some Amtrak connection to Central Valley could end up making a mixed HSR/normal line run from the Bay Area to LA.

Still, it's depressing if not surprising (I've been hesitant about it for a while). Vox tries to explain why HSR has done poorly, a combination of cost overruns, delays, and political overrides of logic, but that's at best a first-level explanation. Why are cost overruns, delays and politics so much worse for American HSR than in other countries?

Maybe our love affair with cars means that everything else gets second-best efforts. There was also some argument making its way around several years ago that English-speaking advanced economies have far more expensive public infrastructure than in comparable non-English speaking countries (couldn't find a good link on a quick search). The reasons given that I recall were stubborn labor unions, which I find a doubtful distinction, and greater legal costs, which also seem overblown to me. The real cause isn't clear.

Anyway I view the HSR failure as a similar disappointment to each carbon-capture project that bites the dust, usually for the same reason of cost overruns and delays. We need these programs to work.

Still, HSR isn't entirely dead, and alternatives like high-speed autonomous EVs in dedicated lanes could provide similar benefits. And people keep trying CCS, maybe it will eventually work as something we desperately need in order to generate large amounts of negative carbon emissions.



UPDATE - some good analysis from Scott Lemieux:

The crucial underlying problem here is America’s fractured and extraordinarily high-veto-point system, which inevitably leads to substantial inefficiencies and inequities unless (as with roads) the support for them is extremely broad-based and the opposition very weak. Any remotely rational plan would have started with a San Diego-to-LA or an LA-Bakersfield-SF line and proceeded from there, but instead so many local interests had to be bought off that it became white elephant done in a completely irrational sequence, and collapsed. And that’s in one of the most favorable political contexts for such a project.

Another related problem is that NIMBYISM has a serious presence on the left, which can be seen in the fact that the Green New Deal completely ignores the critical need for upzoning and increased housing density. These are both very serious issues.

Thursday, February 14, 2019

Eli Rabett's: Dividend and Fee Carbon Taxes


Eli has an idea.  Usual disclaimers.
Let's have a dividend and fee carbon tax. Let's pay the first year dividend and only start to collect the fee in the second, and let's even give bonus' for good deeds, like riding public transport, not using neonicotinoids, giving more carrots to the bunnies and your suggestion goes here.
The Overton window on this is being shoved too and fro.  On the one hand in the US there is a real shift in public opinion toward reality on climate change to it is real, and we must do something about it.  The Green New Deal has a bunch of momentum going for it.  On the other hand the French gilets jaunes have been raising holy hell in the streets of Paris. 

Thus Eli Rabett's simple plan: Pay the first year dividend without collecting the tax.  Institute the tax in the second year.  Where will the money come from the bunnies ask.  Well, think of it as the infrastructure week that the US did not have.  It's an investment, and more will be needed for supporting research and new infrastructure like new nuclear plants and electrical distribution networks.   

So back to the beginning.  Fee and dividend was an idea popularized by Jim Hansen, the idea being that there would be a revenue neutral carbon tax with the revenue being returned to citizens.  In the US this has been taken up by the Citizens Climate Lobby among others including a whole bunch of economists who argue for a carbon fee and dividend plan.  CCL calls for a 100% monthly per person dividend and a border adjustment which would cover the carbon generated in the production and transport of imports. (Eli notes he was one of the first bunnies to talk about the border adjustment feature in the 2007 Eli Rabett's Simple Plan to Save the World).

Now one can argue about the correct costing for a carbon tax, but the general idea is clear and the point of the dividend is to capture the advantages of eliminating CO2 emissions while returning the fee to the public.  Why return the fee, well, some high fees will be needed to get to zero emission, and people will not be happy with paying them (Pay no attention to the folks selling free beer).  Thus pay the dividend up front, tax the carbon later.  Everybody wins



Friday, February 08, 2019

Making Tracks in the US


So with the Green New Deal on the street there is considerable talk about improving railroad travel.  Eli has a couple of perhaps odd points to make.

First high density is NOT something that is needed for fast trains, as a matter of fact it is a hinderance.  It doesn't matter how fast a train is if it has to make a lot of stops and every stop includes significant time decelerating as well as accelerating.  Moreover close to stations a high speed train travels slowly over normal tracks into the station rather than over a high speed right of way.

Ideally the time between stations should be of the order of one to two hours.  For high speed trains this is somewhere between 200 and 400 km (in disgraced units between 120 and 240 miles).  Thus, the East Coast Corridor between Boston and DC might not be a very good place to start as can be seen from the marginal reduction of travel time between the faster trains (Acela Express) and the normal ones on the NY - DC route, much of which is due to additional stops for the slower trains.

So where would be a good place to start.  There are a couple which suggest themselves.  Eli might point to a route linking Minneapolis, Madison, Milwaukee, Chicago, Detroit, Cleveland, Pittsburgh and Philadelphia.


On Twitter, Paul Farrar, pointed out that Texas might be a good place to start.  Houston to Dallas  has been suggested, but such a route could be built out to include Oklahoma City, Kansas City, St, Louis and Chicago from Dallas, and to New Orleans and Austin from Houston.

So there are many possibilities for high speed rail in the US given the political will.

Which brings the blog to Eli's second point.  Railroads in the US are not electrified.  Even for freight there are places where considerable gains in decreased emissions and efficiency could be made by electrification of freight routes. One of the bedevilments limiting high speed rail passenger travel in the US has been that both freight and passenger trains travel on the same route.  Eli would propose that the lowest hanging fruit is electrification of the major freight routes, followed by building out a separate really high speed passenger rail network, starting in the middle of the country, where the land is mostly flat and population density outside of major cities is low.
   

It's perfectly fine to talk on a cell phone in an elevator

I have climate-related tabs piling up on my browser that I wanted to blog about, but felt I had to start with the important and pressing issue in the headline, first.

Mainly, the time spent in an elevator is brief and wasted, so why not continue a cell phone conversation? Should you really hang up for the 30-60 seconds that the elevator ride takes, and then call the person back, all so you could join the other people standing there facing a door (or possibly stare at your phone but without saying anything).

I don't see a point in not talking. On the train or bus, or maybe in a restroom, it's a longer time period where the other people are stuck with your conversation, so I'd understand a rule of courtesy there, but blab away on a brief elevator ride.

Glad to get that settled.

Saturday, January 26, 2019

The left imitating Republicans

I probably should prove something beyond just my sense that it's happening, but I feel that the left side of the political spectrum, a little or a lot closer to where I belong than the other side, is becoming more like Republicans. We believe what we want to believe. Deficits suddenly don't matter any more. We don't like nuclear power and are suspicious of biomass so they're off the table instead of reasoned through. The Republicans careened into office with a president with zero political qualifications for any office, so the Democrats should nominate Oprah Winfrey. A weird and nuanced confrontation between (mostly) white teenagers, a weird cult, and a (not-Vietnam) Native American vet can only be thought of in a single way, and those who rethink it are the liberal version of cucks.

The big advantage America has over say, the UK, is that only one of our two major parties has gone bat-guano insane. We need to keep it that way and hopefully reduce that number over time. It's possible - here in California, Republicans are questionable as a major party (no statewide office in several election cycles, have only about 25% representation in the legislature), and maybe something reasonable will eventually overtake them.

I'm overplaying this a bit. The Oprah boomlet has mostly gone away, and the other issues get pushback. The left seems to be getting over the idea that race is a purely cultural construction but also has complex and nuanced relationship to genetics, one that doesn't fit simplistic racist constructions either.

It's a problem though, and reasonable people need to push back.

Wednesday, January 23, 2019

Horn tooting

In today's San Jose Mercury News (moderately climate-related):

Opinion: Follow the will of voters and protect San Jose’s Coyote Valley
The 7,400-acre valley stretching from San Jose to Morgan Hill feeds our foothills and provides crucial drinking water

By BRIAN SCHMIDT
 
As the rains come and go through San Jose’s winter sky, the rainwater flows as both a blessing and a curse.

What we overlook is the natural function of the rain. One-third of our drinking water comes from local rains — not the distant Sierra — and offers  a blessing for the working farmland that is an easy bike ride from San Jose’s southern edge. The water feeds the city’s green foothills and the animals in our habitat. It makes the streams navigated by our local fish and countless birds. The curse comes from human mismanagement that exacerbates floods, contaminates drinking water and changes the climate globally so we have either too much rain or too little.

Still, we control the curse, or at least the extent of it, and Tuesday San Jose’s leaders have the chance to act locally to protect land in Coyote Valley as a blessing for our community and the entire region.

This 7,400 acre valley, exactly south of South San Jose, is a gem of farmland and natural habitat that has so far stopped the Bay Area’s sprawl. In it lies the critical area where much of the rainwater as it is shed down from the hills – literally, the watershed – collects into Coyote Creek before being funneled into urban San Jose. In the confined stretches around urban streams, the San Jose floods of February 2017 had nowhere to go but into people’s homes. This tragedy could be compounded by mismanagement in the future, because Coyote Valley has long been slated for conversion from farmland and wetland to pavement, funneling still more flooding into San Jose.

The San Jose City Council on Tuesday afternoon will study Coyote Valley. San Jose’s voters set aside up to $50 million in the recently approved Measure T to buy and improve land for purposes of “water supply, flood control, open space and environmental protection of lands such as Coyote Valley.” Whether the council follows the will of 71 percent of the voters is at question, but clearly this valley is a natural sponge that shouldn’t be paved over.

Nor should councilmembers overlook the other reasons to protect Coyote Valley. The one-third of our drinking water from local rains ends up in our underground aquifer, including the valley. No other large area of that aquifer is so close and unprotected as Coyote Valley. The water ponded at the valley’s surface just this last weekend shows how the shallow depths to bedrock keep water near to the surface or even at the surface. We would never build a factory or an industrial warehouse in the middle of a drinking water reservoir, so why would we do that where the groundwater we drink touches the sky?

Still, this valley is under threat, from misguided ideas to replace undeveloped open land between San Jose and Morgan Hill with sprawl. The latest version of that threat would build vast warehouses, replacing Coyote Valley’s life with storage, all for a child’s handful of jobs and not the economic nirvana we were previously promised. This is not what San Jose needs or how the people voted.

The farmland and natural habitat come together here: bobcats, badgers, even mountain lions cross at the valley where mountain ranges come so close they almost kiss. San Jose’s ambitious climate plans mean developing up, not sprawling out.

The blessing that the rains bring, and the curse of our mishandling them, come together at Coyote Valley. San Jose can avoid that curse and create something beautiful by protecting Coyote Valley.


 
Brian Schmidt is the program director for the Greenbelt Alliance.
 

Tuesday, January 15, 2019

Gavin Explains It All

Well, Eli is retired so he is outsourcing to Gavin Schmidt who,explained it all in a series of tweets with the BlackPhysicists Tweeter.  They actually, between them had a real conversation of value, which Eli here unrolls.  Below the BlackPhysicists are in italic.  Gavin does the rest.  The sequence started with.

 @BlackPhysicists  Today our #iteachphysics topic is tools and pedagogy for teaching #weather and #climate physics. One goal of today's #iteachphysics chat is how do physics teachers include in the usual #physics curriculum, absent a specialized course, enough background and foundational knowledge to make our students better consumers of, explainers of #weather and #climate physics

I’d say to start with thermodynamics. Heat, density, convection and then Clausius-clapyeron. Condensation/evaporation and conservation of mass/energy, you have most of the principles. Coriolis rounds it off.

@BlackPhysicists In general #physics we do not spend a whole lot of time on classical #thermodynamics, but thermodynamics is essential in understanding #weather phenomena. See hurricanes described as a Carnot cycle in @PhysicsToday 



 It doesn’t need to be all-in thermo, more just the concepts. PV=nRT, buoyancy, condensation...




@BlackPhysicists  In almost every broadcast meteorologist's report we hear the term "weather model." What are weather models, exactly, and how do they work?




Here is another great animation of a weather model that includes atmospheric composition of aerosols (particulates): 






And here is an excellent primer for climate models

@BlackPhysicists There are enough wildfires and volcano eruptions happening at one time to effect #weather on a large scale?

Good Q. Small volcanoes and fires add to the background climate for sure. Impacts on weather forecasts are more subtle, but by changing where solar/IR energy is absorbed/reflected they can affect temp gradients and hence dynamics.

@BlackPhysicists What do you think re: best practices to teach probability & stochasticity, parameterization & estimation, error and bias?

 More Chaos theory/Lorentz attractor etc. Parameterisation and emergence are trickier but there are some @TEDTalks on that. 


I generally don’t find that numerical analysis as taught is particularly useful though.

 Dust can affect hurricane development (at least it has been hypothesized to). And smoke/aerosols impact air quality directly - something weather models are increasingly predicting as well.

@BlackPhysicists  In fact the group at @NCASNews led by @vernon_morris is expert on dust from the Sahel leading to African Easterly Waves and Western Hemisphere hurricanes. I think in this presentation there a slide showing North American hurricane tracks emanating from the Senegal, Gambia area.

 @BlackPhysicists Switching gears to #climate physics, in your experience do students have difficulty understanding the difference between weather and climate? This seems to be a major problem in TV punditry and probably most public discourse on weather and climate.

Actually no. Once explained - lots of good metaphors available - ppl generally get it. The ‘confusion’ one sees in punditry is fake - a position taken for rhetorical effect rather than any real misunderstanding.

Here’s a good metaphor. Climate is the clothes in your closet, weather is what you are wearing right now. The weather is constrained by the climate (you can’t wear clothes you don’t have), and the closet can change over time (new purchases/gifts), sometimes abruptly!

 @BlackPhysicists What are the basic equations from #physics of a good climate model? What are the dichotomies (false or otherwise) between ‘weather’ models and ‘climate’ models?

Atmospheric physics is basically the same - slightly different levels of truncation (spatial resolution etc) since climate models have to run longer and with more components (oceans, sea ice, composition, biosphere (to some extent)). But major difference in conservation properties and ingestion of observations.

For a weather model, continual updating with observations means small businesses imbalances don’t matter much. But climate models don’t ingest obs like this so small biases can build (model ‘drift’). Conservation is key.  Other issues are the diagnostics one is interested in. With weather, you want the specific trajectory of storms/fronts etc, with climate you want the statistical description (how many storms/what tracks) because that is where the skill is.

Actually, understanding the notion of skill is key for both kinds of model - how can you judge if a model is useful despite it not being perfect?

 @BlackPhysicists  @RogerAPielkeSr offers a lot of great resources in both #weather and #climate. One defn he's offered: Definition 1:Weather is separated by climate just by averaging time period; e.g. a 30 year time average temperature we call "climate" 

That’s been true historically, but that’s a little arbitrary and not fundamental. I would prefer a distinction based on forecasts of specific trajectories vs statistics of trajectories. An example might help.

@BlackPhysicists Right, it is possible, even necessary, to draw a distinction between a time average and more detailed statistics, even as basic as the meaning of standard deviation. That is an important point I think that's lost in a lot intro measurement in #physics 

Take Mt Pinatubo eruption. A very large forcing on the climate system, which had detectable impacts on rainfall, temperature, wind patterns. It didn’t extend the predictability of weather forecasts, however the statistical impacts were predicted skillfully by climate models.

Those climate forecasts were for 1, 2, 3 years out. Much shorter than the ‘30 year’ period you mentioned. The issue is one of signal and noise. For slow changes in forcings (or none), 30 years is a good period to average out a lot of internal variability. But for a big signal (like Pinatubo), the climate impacts easily exceed the ‘noise’ of the weather. Same with the seasons! (Note ‘noise’ here isn’t pejorative- one person’s noise is another’s signal after all). Bottom line, there is no longer single time period that separates weather and climate.

@BlackPhysicists I think a key bridge to build in the #physics curriculum is micro- meso- scale physics of how these things, aerosols, dust, etc affect #weather and #climate. That and the spectral decomposition of light and its effects 

How do you bridge weather models' that are built on 1st principle physics (continuity, Navier-Stokes, advection-diffusion of energy) to climate models? The latter isn't just long-time simulations of the former on meaningful grids and timesteps?

This is of course intended to be a counter-positional question 🤓 #

They aren’t different in principle. But all these models need to have a scale (in time/space) below which they are not resolving the ‘true’ equations. For weather models that scale is a little smaller than for climate models, but for both it’s getting smaller over time.

@BlackPhysicists And that is an important point that I think a lot of people don't get about computational physics, i.e., that pushing computational limits possibly/likely will reveal new physics just like increasing resolution, repetition rate etc of measurement does 

@BlackPhysicists Jan 12 More #iteachphysics @ClimateOfGavin you've been a great help today. Before we end, there are 2 related concepts sea surface temperature and ocean heat content. How can we best explain to students the difference between the two?

More Sea surface temperature is a diagnostic of what’s happening at the surface (duh!). It’s the field that has the direct connection to the atmosphere (via radiation, evap etc.). It is changes in SST that allow for the planet to requilibirate to any change in radiative forcing.

But ocean heat content changes writ large are tied to the planetary imbalance (how much more energy are we bringing in than losing to space). It was predicted in the 1980s that if the predictions of global warming were right for the right reasons, the signal would be in the OHC

Some discussions of that here in the light of recent updates and discussions:

@BlackPhysicists If you have time, could you give your take home message from the @NatureClimate paper that was in the news this week.



@BlackPhysicists I think I meant this report, which is more from an IPCC report at not the @NatureClimate paper. 

It's kind of covered in the @RealClimate piece I tweeted earlier. As non-climatic artifacts are removed from the OHC analyses and more data is being ingested from Argo etc, the predictions from GCMs are being nicely validated.