Updated data calcs. The 2019 estimate had been reduced so going forward requires 4.7% yearly reduction rather than 6/.1%, but as all of the decline in global GHG from 2019 to 2021 was due to Covid, the big question is whether global GHG emissions will plateau in 2023? In other words any sustained decline in GHG is still not clearly visible in the data. Latest calcs and links to data summarized below:
Global GHG emissions would have needed to decline by 4.65%/year from an estimated 54.82 GT CO2e in 2019 ( https://ourworldindata.org/greenhouse-gas-emissions#annual-greenhouse-gas-emissions-how-much-do-we-emit-each-year) to achieve a 35 GT CO2e level in 2030 and a 66% chance of limiting average global temperature increase to below 1.8 C (file:///C:/Users/rbaiman/Downloads/EGR2022-3.pdf , Table ES.2). However, global GHG emissions declined by an average of only 0.3% a year from 2019 to an estimated 54.49 GT CO2e in 2021 ( https://ourworldindata.org/greenhouse-gas-emissions#annual-greenhouse-gas-emissions-how-much-do-we-emit-each-year ). As a consequence , we must now reduce global GHG emission by 4.7% per year to reach 35 GT by 2030. There is no real-world scenario under a system of voluntary NDCs that will produce a 4.7%/year reduction in CO2e. Indeed, the 0.3% yearly GHG reduction from 2019 to 2021 is less than 1/15th of the 4.7% yearly reduction needed, and that reduction was largely attributed to the Covid-10 Pandemic. In 2022, global GHG emissions increased and, depending on the state of the economy, could potentially plateau in 2023 or increase, not decline ( https://www.scientificamerican.com/article/will-global-emissions-plateau-in-2023-four-trends-to-watch/ ) Best, Ron On Wed, Apr 12, 2023 at 4:56 AM Robert Chris <[email protected]> wrote: > Doug > > This more nuanced response covers the bases. Thanks. I particularly > relate to your comment that the policy relevance of models is not a binary > 'they are/they aren't'. Unfortunately that isn't how they're regarded by > many influential people who should know better. The real value of models > is their ability to interrogate the relationships between baskets of > climate relevant variables and not in their ability accurately to predict > future climate states of the planet. The models may well have their own > internal consistency but it is a challenge, even for the better informed, > to grasp the extent to which they are truly predictive. This isn't helped > by the use of global aggregates and averages that mask wide spatial and > temporal variability. > > BTW, I wasn't suggesting that 'if we don’t correctly capture what the > temperature would be in the year 3000, then it follows that our models are > utterly useless for making near-term policy choices'. The point I was > trying to make is that we need to abandon the idea that any short term > policy goal, e.g. net zero by 2050, is job done, global warming solved, > let's move on. Whether net zero by 2050 is even sufficient to avoid a > climate catastrophe in the relatively near future is an open question. But > crucially, so long as we've got 8 billion or so people all wanting the > latest gizmo and longer vacations in far away places, global warming is a > situation that will have to be continuously managed into the distant future > and therefore our short term policy choices should always be open to > adaptation as the future unfolds. That requires more of a change in > policymakers' and the public's attitude towards the science, than it does > in the processes of science itself. > > Of course if in a century or so we're back down to 1 billion or so, where > we were not so long ago, then most of the global warming problem gets > sorted by natural ecosystems. Maybe that's the most cost effective way of > addressing global warming - sit back, do next to nothing to make the > unsustainable sustainable and just let nature take it course😉. > > Regards > > Robert > > > On 12/04/2023 01:50, Douglas MacMartin wrote: > > I did not state that the models are not policy-relevant… both because I > don’t agree with that being a binary statement of either they are or they > aren’t (rather, they are useful for answering some questions and less > useful for answering others), and because the specific issue I was > responding to is not the most relevant factor in thinking through that > question. > > > > I disagree completely with your assertion that if we don’t correctly > capture what the temperature would be in the year 3000, then it follows > that our models are utterly useless for making near-term policy choices. > Rather, I think that what happens in the next century or two actually do > matter. I agree with you that what happens beyond then **also** matters, > but I don’t think it is essential that a climate model correctly capture > that. You don’t need to run a climate model to say that we’re in trouble > if we maintain elevated CO2 concentrations for the next 1000 years, as this > thread points out, and climate models aren’t necessarily useless simply > because they ignore physics that isn’t (necessarily) relevant to predicting > nearer-term impacts. > > > > And I do agree that the degree of uncertainty in heading into uncharted > territory is not well understood, including the possibility of more rapid > changes than are predicted in current climate models. But I think there’s > a lot of room between “climate models are perfect representations of the > future” and “climate models are not policy-relevant”; just because they are > obviously not perfect does not make them totally useless as you seem to > suggest… > > > > > > > > *From:* Robert Chris <[email protected]> <[email protected]> > *Sent:* Tuesday, April 11, 2023 8:23 AM > *To:* Douglas MacMartin <[email protected]> <[email protected]>; > [email protected]; Tom Goreau <[email protected]> > <[email protected]> > *Cc:* [email protected]; Planetary > Restoration <[email protected]> > <[email protected]>; 'Eelco Rohling' via NOAC > Meetings <[email protected]> <[email protected]>; > geoengineering <[email protected]> > <[email protected]> > *Subject:* Re: [prag] Re: [geo] Are 1.5 c or 2.0 c thresholds > economically realistic in a voluntary NDC regime? > > > > Doug > > It seems that mistakenly I thought you were justifying the appropriateness > of the models. Apologies. On a closer reading, the following emerges: > > Your final words 'That isn’t what the models are intended to do', in > context, mean that we shouldn't criticise the models for not being > policy-relevant even though they exclude millennial factors because the > models are not intended to be policy relevant. They are just models that > produce certain outputs based on certain inputs and certain algorithms. > The degree to which the models are a faithful predictor of the range of > plausible futures is unknowable until that future arrives, and made more so > by the absence of the millennial factors. Policymakers use these models at > their (and our) peril. > > Have I got that right? If so, it might be a good idea if someone told the > policymakers that they're basing their policies on the wrong data. > > Regards > > Robert > > > > On 11/04/2023 17:31, Douglas MacMartin wrote: > > Robert, > > > > I agree with almost everything you write, except for your belief that what > you wrote is in any way in conflict with what I wrote. > > > > doug > > > > *From:* Robert Chris <[email protected]> <[email protected]> > *Sent:* Tuesday, April 11, 2023 3:17 AM > *To:* Douglas MacMartin <[email protected]> <[email protected]>; > [email protected]; Tom Goreau <[email protected]> > <[email protected]> > *Cc:* [email protected]; Planetary > Restoration <[email protected]> > <[email protected]>; 'Eelco Rohling' via NOAC > Meetings <[email protected]> <[email protected]>; > geoengineering <[email protected]> > <[email protected]> > *Subject:* Re: [prag] Re: [geo] Are 1.5 c or 2.0 c thresholds > economically realistic in a voluntary NDC regime? > > > > Doug > > There's a significant caveat in there - assuming we 'eventually get to net > zero', and a significant ethical assumption - that policy relevance is > limited to a century timescale. And a further physical climate assumption > - that cascading tipping events will not be triggered on any plausible > current and short term policy regime. > > If you set the rhetoric aside, there's little evidence to suggest that by > mid-century or even for a decade or more after that, we'll get to net > zero. Your 'eventually' is doing a lot of work here! For this to happen > requires us to start the decommissioning of fossil fuel assets now and > scaling GGR/CDR to close to or beyond GtCO2e/yr within the next few years. > Current geopolitics shows no sign of substantive action to match the > rhetoric on either of those, or the likelihood of any imminent breakthrough > that might materially accelerate things. > > As to the ethical assumption, if the ethics are constrained to consider > only the scenarios in which we get to net zero, then you need to be pretty > damn sure you're going to get there. But we're far from being sure about > that. So limiting policy relevance to the century timescale is tantamount > to declaring that what happens beyond that is no concern of ours. This is > like setting a discount rate that reaches infinity on 1 Jan 2100 (or maybe > 2103) - all benefits and costs thereafter have no present value today so we > don't need to worry ourselves about them. An ethics so constrained seems > to me seriously dysfunctional. > > On the tipping events, the literature on this suggests that we are already > treading on thin ice. Is it sane to base our policy regime on the > assumption that there are no tipping points that might derail our smooth > but slow transition to net zero? > > Regards > > Robert > > > > On 11/04/2023 01:07, Douglas MacMartin wrote: > > Also, of course, the long-term response is only realized if nobody ever > develops and deploys any CDR over that long-term timeframe. > > > > If you believe that we will eventually get to net-zero and that some level > of CDR will get deployed to go below net-zero, then it’s the century-scale > warming that matters, not the millennial-scale. > > > > There are of course millennial-scale processes that are not included in > climate models, so there’s neither any reason to expect them to match on > that time-scale, nor any reason to criticize them on that particular basis, > or to use that particular argument to suggest that the models aren’t > policy-relevant. That isn’t what the models are intended to do. > > > > *From:* [email protected] <[email protected]> > <[email protected]> *On Behalf Of *Michael MacCracken > *Sent:* Monday, April 10, 2023 1:54 PM > *To:* Tom Goreau <[email protected]> <[email protected]>; > Robert Chris <[email protected]> <[email protected]> > *Cc:* [email protected]; Planetary > Restoration <[email protected]> > <[email protected]>; 'Eelco Rohling' via NOAC > Meetings <[email protected]> <[email protected]>; > geoengineering <[email protected]> > <[email protected]> > *Subject:* Re: [prag] Re: [geo] Are 1.5 c or 2.0 c thresholds > economically realistic in a voluntary NDC regime? > > > > Well, in that the climate depends on the radiative forcing and the > radiative forcing is logarithmic with the CO2 concentration, doing a linear > regression of CO2 and temperature would give an estimate of the rise in > temperature that is far from linear, so the 16 C would be way too high. > > There is then the issue that the change in temperature in high latitudes > is well above the global average change in temperature, and so that would > be another contribution to giving a rate too high for the change in global > average temperature. So, if regression were to get temperature change in > high latitudes ad not the global average, one would have a value more than > the change in the global average temperature. > > Mike > > On 4/10/23 1:29 PM, Tom Goreau wrote: > > It’s just the regression of Antarctic Ice temperature versus CO2 data. The > sea level regression implies +23 meters. > > > > When I did it in 1990 there was only one glacial cycle of data, but Eelco > Rohling independently did the same analysis when there was 800,000 years of > data, and got essentially identical values. > > > > The models must be serious underestimates to fall so far off the actual > long term climate data. > > > > > *Thomas J. F. Goreau, PhD President, Global Coral Reef Alliance* > > > *Chief Scientist, Blue Regeneration SL President, Biorock Technology Inc.* > > *Technical Advisor, Blue Guardians Programme, SIDS DOCK* > > *37 Pleasant Street, Cambridge, MA 02139* > > > > > *[email protected] <[email protected]> www.globalcoral.org > <http://www.globalcoral.org> Skype: tomgoreau Tel: (1) 617-864-4226 (leave > message)* > > > > *Books:* > > *Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon > Sequestration, and Reversing CO2 Increase* > > http://www.crcpress.com/product/isbn/9781466595392 > > > > *Innovative Methods of Marine Ecosystem Restoration* > > http://www.crcpress.com/product/isbn/9781466557734 > > > > *No one can change the past, everybody can change the future* > > > > *It’s much later than we think, especially if we don’t think* > > > > *Those with their heads in the sand will see the light when global warming > and sea level rise wash the beach away* > > > > *Geotherapy: Regenerating ecosystem services to reverse climate change* > > > > > > > > *From: *Michael MacCracken <[email protected]> <[email protected]> > *Date: *Monday, April 10, 2023 at 4:23 PM > *To: *Tom Goreau <[email protected]> <[email protected]>, > Robert Chris <[email protected]> <[email protected]> > *Cc: *"[email protected]" > <[email protected]> > <[email protected]> > <[email protected]>, Planetary Restoration > <[email protected]> > <[email protected]>, 'Eelco Rohling' via NOAC > Meetings <[email protected]> <[email protected]>, > geoengineering <[email protected]> > <[email protected]> > *Subject: *Re: [prag] Re: [geo] Are 1.5 c or 2.0 c thresholds > economically realistic in a voluntary NDC regime? > > > > Hi Tom--I'd be interested in seeing your 1990 paper because 16 C would > take temperatures to much higher than they have ever been, and yet there > have been periods when the CO2 concentration has apparently been well above > 1000 ppm, so the 16 C value seems seriously inconsistent with what we know > of Earth history. > > Best, Mike > > On 4/10/23 5:02 AM, Tom Goreau wrote: > > BEFORE UNFCCC was signed, it was clear from paleoclimate data that +16 > degrees C or so is the equilibrium temperature for 400ppm CO2 (Goreau > 1990), but all governments ignored the real data because they preferred the > fictitious claim from models that warming would “only” be around 1-4 > degrees C, and occur well after a new leader emerges from the next > election, selection, or coup. > > > > I briefed the Association of Small Island States just before they signed > on to a treaty that was an effective death sentence for low coasts and a > suicide pact for low lying island nations to that effect, but their heads > of states were told by the rich countries to sign or they would lose their > foreign aid, something none could afford. They were effectively bought off > to sacrifice their own people’s futures for worthless promises of financial > support for adaptation that never came. No politician ever turns down > money, no matter how insufficient. > > > > Instead what they got from the funding agencies was sea walls made from > concrete and rock imported half way across the world, which have all fallen > down due to erosion caused by wave reflection scouring. Their consultants > keep promising that the next seawall, built to armor the ruins of previous > seawalls, will last forever, it’s another shell game with peoples futures. > > > > > *Thomas J. F. Goreau, PhD President, Global Coral Reef Alliance* > > > *Chief Scientist, Blue Regeneration SL President, Biorock Technology Inc.* > > *Technical Advisor, Blue Guardians Programme, SIDS DOCK* > > *37 Pleasant Street, Cambridge, MA 02139* > > > > > *[email protected] <[email protected]> www.globalcoral.org > <http://www.globalcoral.org> Skype: tomgoreau Tel: (1) 617-864-4226 (leave > message)* > > > > *Books:* > > *Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon > Sequestration, and Reversing CO2 Increase* > > http://www.crcpress.com/product/isbn/9781466595392 > > > > *Innovative Methods of Marine Ecosystem Restoration* > > http://www.crcpress.com/product/isbn/9781466557734 > > > > *No one can change the past, everybody can change the future* > > > > *It’s much later than we think, especially if we don’t think* > > > > *Those with their heads in the sand will see the light when global warming > and sea level rise wash the beach away* > > > > *Geotherapy: Regenerating ecosystem services to reverse climate change* > > > > > > > > *From: *Michael MacCracken <[email protected]> <[email protected]> > *Date: *Sunday, April 9, 2023 at 9:37 PM > *To: *Tom Goreau <[email protected]> <[email protected]>, > Robert Chris <[email protected]> <[email protected]> > *Cc: *"[email protected]" > <[email protected]> > <[email protected]> > <[email protected]>, Planetary Restoration > <[email protected]> > <[email protected]>, 'Eelco Rohling' via NOAC > Meetings <[email protected]> <[email protected]>, > geoengineering <[email protected]> > <[email protected]> > *Subject: *Re: [prag] Re: [geo] Are 1.5 c or 2.0 c thresholds > economically realistic in a voluntary NDC regime? > > > > Hi Tom--Indeed, which is why I don't understand why the mainly island > nation accepted, even insisted upon 1.5 C, as an aspirational goal. From > paleoclimatic analysis, the equilibrium sensitivity for sea level rise is > of order 15-20 METERS per degree C increase in the global average > temperature. And how it is somehow justified that the curve shape for the > sensitivity is a cubic and we are presently in the low sensitivity part of > the curve does not at all seem justified to me (though perhaps the type of > major ice sheet matters). > > I once asked the chief US negotiator (Todd Stern) at the Paris COP if they > had viewed as a value that would be an upper limit and the subsequent goal > and actions would be aimed at forcing the global average temperature back > down, or if the vision was that actions would be taken to keep the increase > in global average temperature to be 2 C and this would be an allowed long > term value for the Earth. He indicated, as I recall, that what would happen > after the value was reached was not discussed, they were so happy to have a > number to consider an upper value they just never discussed the issue. > > Best, Mike > > On 4/9/23 7:40 AM, Tom Goreau wrote: > > The 1.5 degree “goal” like the 2.0 goal, is beyond the capacity of corals > to adapt so it means the extinction of coral reef ecosystems, which already > reached their high temperature tipping point in the mid 1980s. > > > > Coral reefs, and the species and people who live from them, have been > consciously selected for sacrifice, rather than interrupting profits from > fossil fuels. > > > > Coral reefs may be the first ecosystem to collapse, but they certainly > won’t be the last! > > > > > *Thomas J. F. Goreau, PhD President, Global Coral Reef Alliance* > > > *Chief Scientist, Blue Regeneration SL President, Biorock Technology Inc.* > > *Technical Advisor, Blue Guardians Programme, SIDS DOCK* > > *37 Pleasant Street, Cambridge, MA 02139* > > > > > *[email protected] <[email protected]> www.globalcoral.org > <http://www.globalcoral.org> Skype: tomgoreau Tel: (1) 617-864-4226 (leave > message)* > > > > *Books:* > > *Geotherapy: Innovative Methods of Soil Fertility Restoration, Carbon > Sequestration, and Reversing CO2 Increase* > > http://www.crcpress.com/product/isbn/9781466595392 > > > > *Innovative Methods of Marine Ecosystem Restoration* > > http://www.crcpress.com/product/isbn/9781466557734 > > > > *No one can change the past, everybody can change the future* > > > > *It’s much later than we think, especially if we don’t think* > > > > *Those with their heads in the sand will see the light when global warming > and sea level rise wash the beach away* > > > > *Geotherapy: Regenerating ecosystem services to reverse climate change* > > > > > > > > *From: *<[email protected]> > <[email protected]> on behalf of Robert > Chris <[email protected]> <[email protected]> > *Date: *Sunday, April 9, 2023 at 10:35 AM > *To: *Michael MacCracken <[email protected]> <[email protected]> > *Cc: *"[email protected]" > <[email protected]> > <[email protected]> > <[email protected]>, Planetary Restoration > <[email protected]> > <[email protected]>, 'Eelco Rohling' via NOAC > Meetings <[email protected]> <[email protected]>, > geoengineering <[email protected]> > <[email protected]> > *Subject: *Re: Fwd: [prag] Re: [geo] Are 1.5 c or 2.0 c thresholds > economically realistic in a voluntary NDC regime? > > > > Mike, you point to a key distinction that I had perhaps ignored. The > dynamics of setting goals are not the same as those of realising them. > > Economics may have been a major factor in setting the Paris targets but > they are not an enabler of their realisation. If the political will was > there among a sufficient number of leading economies to deliver on the > Paris targets, they would find a way of doing that that would overcome any > economic constraints that might otherwise have been thought to be > impediments. > > Regards > > Robert > > > > > > > > > > > As I loosely recall, when the 2 C goal was approved in Paris, the value > was chosen because it was thought that it would be > realistically/economically achievable. The goal could not be higher due > to thoughts about tipping points or lower due to economic > realities--though they did set 1.5 C as an aspirational goal as the > developing nations felt the impacts of 2 C on them would be unbearable. > So, I'd say economics played a goal there--indeed, even the primary > rationale for the choice. > > Mike > > On 4/8/23 9:54 AM, Robert Chris wrote: > > David, you've put your finger right on it. Being economically > > realistic is not a sufficient condition to enable the realisation of > > any goal. For some goals, it isn't even a constraint because for > > them, what is economically realistic is made to fit the goal, rather > > than the goal being tailored to fit what's economically realistic. > > Money is not the only store of value. > > > > Regards > > > > Robert > > > > > > On 08/04/2023 18:26, David desJardins wrote: > >> If the goal is always economically realistic, then it follows that > >> looking at the goal through an economic lens will always enable it, > >> not prevent it. > > > > -- > You received this message because you are subscribed to the Google Groups > "Healthy Planet Action Coalition (HPAC)" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/healthy-planet-action-coalition/c1cc3b97-4f27-0715-7bc2-9e09145d5129%40gmail.com > <https://groups.google.com/d/msgid/healthy-planet-action-coalition/c1cc3b97-4f27-0715-7bc2-9e09145d5129%40gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > > > > > > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/393de190-888b-c427-bccb-9588e8514a55%40gmail.com > <https://groups.google.com/d/msgid/geoengineering/393de190-888b-c427-bccb-9588e8514a55%40gmail.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "Planetary Restoration" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/planetary-restoration/c325e421-2d2f-c721-5a14-252e6be21047%40gmail.com > <https://groups.google.com/d/msgid/planetary-restoration/c325e421-2d2f-c721-5a14-252e6be21047%40gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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