https://youtu.be/WNEQo6lk9ko
On Sat, 15 Jun 2019 07:25 Ian Clark, <[email protected]> wrote: > Thank you, Donna. There is material here I can use in additional case > studies to exhibit TABULA in action. > > Yes, I'm using out-of-date figures, but they're nicely rounded figures, > which make it easier to see what's going on in the model. Even if I used > up-to-date figures (…and I was aware of them), they'd go out of date by > next year. Things are beginning to move fast. > > But one of my points of concern was checking primary sources for the input > figures to the model. If these figures show different values to the ones > I've used, e.g. 415 ppm as against my >400, then should I use actual > figures, or nice tidy ones that make for an uncluttered display? I haven't > come to a decision about this. There are arguments both ways. > > It's no big deal to extend the model to estimate the number of plants that > Carbon Engineering would have to build, and the fact that SAMPLE9 doesn't > do that is arguably an omission. But to calculate it I'd need to pluck a > figure out of the air for a completion date for the project. The UK has > just committed to becoming carbon neutral by 2050. Is that a figure I > should challenge? No, because it's in print from official sources and > easily checked. But if one were to ask: is that a reliable figure to plan > on, I have my doubts, because pressure is already growing to bring the date > forward by two or three decades. > > So the region of doubt is so large that maybe it's best to leave that > particular calculation out of SAMPLE9. After all, I'm not proposing to use > it to advise the British government. I'm proposing to use it to teach > 14-18-year-olds what mathematical modelling is all about and how to use > TABULA for this sort of thing. Here simplicity scores over accuracy. > Refining the model is an exercise left to the reader. > > A UK Treasury official told me once they had a saying: figures can't lie, > but lies can figure. I'm leaning over backwards *here* (and I stress > "here") to avoid muddying the clear waters of mathematical modelling with > preaching, or anything that could be mistaken for it. Gottfried Leibnitz > had a vision of a world in which debates on public policy would not be > conducted in an atmosphere of passion and ignorance, where nobody could > distinguish evidence from prejudice. Instead he foresaw… "…if controversies > were to arise, there would be no more need of disputation between two > philosophers than between two calculators. For it would suffice for them to > take their pencils in their hands and to sit down at the abacus, and say to > each other […]: Let Us Calculate." > > I share that vision. TABULA is my 21st-century abacus – my 2-cents > contribution to its fulfilment. > > That's not to say we shouldn't start another thread on the topic of global > warming and have a good sound-off about it. But others might reasonably ask > whether that debate isn't better conducted on other platforms, such as > Nature https://www.nature.com/npjclimatsci/ > > Meanwhile I've appealed to the collective wisdom of the J community for > their views on the way I've chosen to promote TABULA. In particular the > models I've chosen as mini case studies. I badly need its answers, and hope > to use them. It's a big question I've asked, but a restricted one. I'm keen > to focus on the topic (in this thread) because I'm afraid that bringing in > wider issues will either derail the proceedings or dilute them and make it > hard to recognise answers I can use. > > The updated figures you've kindly provided don't make a lot of difference > to the "bottom line", if we can call item {13} that. What I'm afraid of are > factors of 10 or 100 creeping in. The great thing about published estimates > for the things I'm calculating is: if they're the same order of magnitude > then it's some assurance that TABULA itself isn't injecting gross errors > into the estimate. > > > > On Sat, 15 Jun 2019 at 01:53, Donna Y <[email protected]> wrote: > > > > I'd be happy if I could establish the model as at > > > least being a start in the direction of accurately costing the carbon > in > > > the atmosphere. > > > > > > > > https://code.jsoftware.com/wiki/TABULA/samples/cost_to_capture_atmospheric_CO2 > > < > > > https://code.jsoftware.com/wiki/TABULA/samples/cost_to_capture_atmospheric_CO2 > > > > > > > > Atmospheric CO2 concentration has been rising steadily since 1960, when > > it > > > first began to be measured regularly at Mauna Loa, HI. At that time it > > > stood at <320 ppm (parts-per-million). Now it stands at >400 ppm, an > > > increase of over 80 ppm. > > > > Yes my comment was about what you said you wanted to model and not > TABULA. > > > > > > This April, the concentration of carbon dioxide in the atmosphere hit 415 > > parts per million for the first time. It’s the highest level in human > > history. > > > > Current emissions are around 40 giga-tons a year. > > > > So far – we got a free ride--forests and oceans mop up more than half our > > carbon waste. > > > > To reduce levels the best thing would be to curb carbon emissions now. > > > > To model CO2 in the atmosphere you need to account for ongoing sources > and > > sinks—its not static, it's a carbon cycle. > > > > In terms of sinks, someone mentioned forests, someone mentioned > > phytoplankton in the ocean, and I mentioned coastal habitats (see Blue > > Carbon). Mounting CO2 in the atmosphere mopped up by the ocean is making > > large sections of the ocean anoxic—these are not bottomless sinks. > > > > It's acceptable to use Mauna Loa data as a proxy for global CO2 levels > > since CO2 mixes well throughout the atmosphere. The trend in Mauna Loa > CO2 > > (1.64 ppm per year) is statistically indistinguishable from the trend in > > global CO2 levels (1.66 ppm per year). There is a history of atmospheric > > CO2, derived from the Mauna Loa observations back to 1958. > > > > Annual CO2 levels from Mauna Loa--60 data points (that would seem easy to > > cross check) > > > > With ice core, data goes back to year 900. > > > > Longer history of atmospheric CO2 was reconstructed from studies of > > deep-sea sediments > > > > To find atmospheric CO2 levels equivalent to the present, we have to go > > back 2.5 million years > > > > 1 ppmv of CO2= 2.13 Gt of carbon > > > > Enough direct air capture to remove current emissions would take 40,000 > > large Carbon Engineering plants that they say will capture 500,000 tons > of > > CO2 annually. > > > > Carbon Engineering published a paper saying that it had dropped costs to > > around $94 to $232 a ton. That assumes selling the CO2—it can be sold for > > as much as $350 a ton in niche applications, like remote soda bottling > > plants—the market would quickly be saturated. Your $100 cost is a net > cost > > assuming the CO2 can be sold. It does not include the cost of carbon > > storage. > > > > Clean Power Plan (US EPA 2015) $11 per ton CO2—would have resulted in > > large emissions reductions for a cost far below the $100 in your model. > > > > Example Carbon sinks: > > > > 83% of the global carbon cycle is circulated through the ocean. > > > > Coastal habitats account for approximately half of the total carbon > > sequestered in ocean sediments. > > > > Forests and oceans both draw in carbon dioxide from the atmosphere, > > —reforestation—$ 1—$10 per ton CO2 > > > > Paradox: Three billion years ago, the sun was only about 70 percent as > > bright as it is today. Earth should have frozen over, but it didn’t. Why > > not? > > Because greenhouse gases in the atmosphere, mainly methane and carbon > > dioxide, trapped enough of the sun’s heat to keep temperatures above > > freezing. When photosynthetic organisms produced enough oxygen it reacted > > with the methane in the atmosphere, transforming it forever. About two > > billion years ago, the methane haze cleared and the sky turned blue. > > > > > > > > In the world of a Pigouvian tax (cost imposed on activities that create > > social harms), markets sort out the most cost-effective ways to reduce > > emissions > > > > > > > > Blending corn ethanol into gasoline up to a 10 percent ratio provides > > essentially costless emissions reductions (replacing more expensive > octane > > booster) > > Replacing coal-fired electricity generation with natural gas > > Using an electric vehicle in a region in which electricity is generated > by > > coal has approximately the same CO2 footprint a gas fuelled vehicle. > > > > Aim to minimize the cost of mitigation both today and into the future, > > recognizing that actions taken today can influence future costs. > > > > > Some groups have taken a stab at calculating what climate change will > > cost the world, or conversely, how much humanity would save by becoming > > more sustainable. Earlier this month, the Global Commission on the > Economy > > and Climate < > > > https://www.vox.com/energy-and-environment/2018/9/5/17816808/sustainability-26-trillion-global-commission-economy-climate > > > > tallied the number at a truly massive $26 trillion in savings by 2030. > > > > > Critically, it’s also the foundation of US climate policies, including > > the Clean Power Plan < > > > https://www.vox.com/2018/8/21/17763916/epa-clean-power-plan-affordable-clean-energy > >. > > Revising this number down has been a key part of the Trump > administration’s > > strategy to roll back environmental rules < > > > https://www.vox.com/energy-and-environment/2018/1/29/16684952/epa-scott-pruitt-director-regulations > >. > > Under Obama, the social cost of carbon < > > > https://19january2017snapshot.epa.gov/climatechange/social-cost-carbon_.html > > > > was set at $45 per ton < > > > https://blogs.wsj.com/experts/2017/11/15/trump-vs-obama-on-the-social-cost-of-carbon-and-why-it-matters/ > > > > of carbon dioxide; under Trump, it’s as little as $1. > > > > > > Donna Y > > > > [email protected] > > > > > > > On Jun 9, 2019, at 11:15 PM, Ian Clark <[email protected]> wrote: > > > > > > Sorry, Donna & Greg, off-topic. I didn't want to start a disputation > > about > > > climate science per-se. If I didn't make that clear, I'm really sorry. > > > > > > This thread's for mathematical modelling with sufficiently transparent > > and > > > trusty software; TABULA in particular; plus suggestions for how to > > provide > > > assurance that it is to be trusted. > > > > > > Or alternatively, establish that it isn't. > > > > > > Then there's how much trust to place in the model itself, but that's a > > > different issue -- a colossal one. Maybe that needs a thread of its own > > too. > > > > > > Except that the 11 built-in models are part of the TABULA release, so > > maybe > > > we need some assurance about those, or at least a clear statement of > > their > > > assumptions and limitations. > > > > > > > > > > > > On Sun, 9 Jun 2019 at 23:35, Donna Y <[email protected] <mailto: > > [email protected]>> wrote: > > > > > >>> The ocean acts as a carbon sink and covers 71% of the earth’s surface > > >> (and is 270 times greater in mass than the atmosphere > > >>> > > >>> coastline is extensive enough to wrap around the earth almost fifteen > > >> times (372,000 miles!). The study found that annually, such ecosystems > > >> could trap and store 2 to 35 times more carbon than even ocean > > phytoplankton > > >> > > >> Donna Y > > >> [email protected] > > >> > > >> > > >>> On Jun 7, 2019, at 2:28 PM, greg heil <[email protected]> wrote: > > >>> > > >>>> If good/cheap/big/fast carbon sinks are up for discussion i would > > >> recommend phytoplankton... Salmon are tasty too, but that is a side > > dish. > > >>> > > >>> > > >> > > > https://www.vox.com/the-highlight/2019/5/24/18273198/climate-change-russ-george-unilateral-geoengineering > > >> < > > >> > > > https://www.vox.com/the-highlight/2019/5/24/18273198/climate-change-russ-george-unilateral-geoengineering > > < > > > https://www.vox.com/the-highlight/2019/5/24/18273198/climate-change-russ-george-unilateral-geoengineering > > > > > >>> > > >>> > > >>> ~greg > > >>> http://krsnada <http://krsnada/> <http://krsnadas.org/ < > > http://krsnadas.org/>> > > >> ---------------------------------------------------------------------- > > >> For information about J forums see > http://www.jsoftware.com/forums.htm > > <http://www.jsoftware.com/forums.htm> > > >> > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > < > > http://www.jsoftware.com/forums.htm> > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
