Kevin, I believe you have misinterpreted Mike’s comment. He was adding clarity to the fundamental issue, which he simply stated as follows. Is the large carbon sink that we observe in recent years (large in the sense that the observed 5 Gt of carbon removed from the atmosphere each recent year is ~ half of recent annual emissions) driven by each year's emissions or by the amount by which the current atmosphere is out of physical and chemical equilibrium with the current ocean/biosphere.
Your Point 1. Under either of the two options above (sink driven by annual emissions versus sink driven by disequilibrium between atm. and ocean/land) you can explain the data you show. Point 2. You seem to be confusing the annual photosynthesis/decomposition cycle, which has opposing phase between hemispheres, with the interannual trends. Point 3: Relative to the rates of both temperature and CO2 changes in the Vostok record, the rates are much higher in recent decades, invalidating your conclusion. The models I have seen and worked with suggest that if we zero out emissions today, then a year from now the atmospheric CO2 level will be about 2 to 2.5 ppm lower than it is now. And that over the next several decades the sink strength will gradually diminish to zero as the atmosphere approaches equilibrium with the oceans and the terrestrial sinks saturate. We won’t get down to 300 ppm that way, but down to 380 ppm is quite plausible and 350 is possible. Protecting and enhancing these natural sinks, along with rapid transition to clean energy, seems to me to provide the most bang for the buck. What keeps me up at night is the concern that warming and other anthropogenic activity will trigger feedbacks that wipe out the natural sinks and create new sources. At the same time, R&D on back-up technologies in case the feedbacks kick in also makes sense. John Harte Professor of the Graduate School Ecosystem Sciences ERG/ESPM University of California Berkeley, CA 94720 [email protected] > On Aug 13, 2021, at 2:46 AM, Kevin Lister <[email protected]> wrote: > > Hi John, I see that Mike has gotten to the answer while I've been drafting my > response, but here are some further numbers and positions to support his > argument and the point that I was making...... > > Point 1 > > There is nearly perfect correlation between CO2 concentration and fossil fuel > consumption, with R^2=0.9991 from 1965 to 2019. 1965 is when BP started > collecting the best reliable set of fossil fuel consumption. The relationship > is likely to now be broken with the forest fires and other large scale CO2 > releases - I not gotten round to checking. > > <image.png> > > Atmospheric CO2 concentration started rising immediately at the start of the > industrial revolution, when emissions were much lower than they are today. So > we can be reasonably sure that the straight line relationship above can be > extrapolated back to the start of the industrial revolution. Therefore, at > best, the rate of permanent CO2 removal must be constant otherwise the > relationship would not be a straight line, and it must be very small > otherwise the atmospheric concentrations would not have responded so quickly > at the start of the industrial revolution. > > Point 2 > > From the slope of the line and the high correlation, we can get a reasonable > prediction of what change in atmospheric CO2 levels equates to CO2 emissions. > We also know that the annual cycle is about 8ppm, so from this we can > conclude that approximately 32,059 million tonnes of carbon are absorbed from > the atmosphere each summer, but these are emitted back in the winter. So this > cycle is in the same order of magnitude that you have suggested, but this is > not permanent Carbon storage. Getting carbon deep into the ground where it > does not come back up is what we need to do, but this is different from the > annual cycle and a much slower process. From recollection IPCC AR5 gave a > figure of 0.2 million tonnes of permanent carbon removal per year, and this > concurs with the observations above. > > Point 3 > > The extremely low rate of permanent removal is independently verified in the > data from the Vostok Ice Core which shows consistent CO2 removal over the > last 4 interglacial cycles. When applying this rate of permanent removal to > the 450ppm, we get a 250,000 year time period to return to the upper limits > of past CO2 concentrations in interglacial cycles, see graph below: > > <image.png> > > > So, finally..... > > I absolutely agree with you that we must protect and enhance natural sinks, > but even when doing this, it is unlikely that it will result in a CO2 removal > rate that would enable safe levels to be permanently maintained in a time > period that is not measurable in hundreds of thousands of years. > > So... > > We need to find reliable albedo enhancement methodologies that we can deploy > for the ultra long term and that are quickly able to return temperatures back > to those around 1980 when self amplifying feedback mechanisms were first > triggered. > > > Kevin > > > > > > > > > On Thu, Aug 12, 2021 at 9:46 PM John Harte <[email protected] > <mailto:[email protected]>> wrote: > Kevin, you write: "Finally, and as you point out, carbon removal will be > slow. The natural rate of removal is so slow as to not be measurable against > CO2 emissions”. > > The current rate of removal of atmospheric carbon dioxide by natural marine > and terrestrial processes is about 5 Gt(C)/year, which is about half of > current annual anthropogenic emissions. > > That hardly seems to be unmeasurably slow! > > Were we to cease emissions today those natural sinks would persist but with > diminishing strength in the future as the atmospheric level draws down. The > sinks will not get the atmosphere down to a pre-industrial CO2 level of > course, but they will nevertheless make a big difference. > > Among the most important things we can do is to stop degrading those natural > sinks … protecting them is cheaper, would accomplish more than engineering > artificial sinks, and would also provide numerous co-benefits. > > > John Harte > Professor of the Graduate School > Ecosystem Sciences > ERG/ESPM > University of California > Berkeley, CA 94720 > [email protected] <mailto:[email protected]> > > > > > > > > > >> On Aug 12, 2021, at 5:01 AM, Kevin Lister <[email protected] >> <mailto:[email protected]>> wrote: >> >> To answer Robert's comments on not seeing a downside to his proposal, and in >> the immortal intellectual framework of a previous Secretary of Defence: >> >> There are known knowns, these are: >> >> >> If you are dropping wind turbines out of a plane, then best guess is that >> these would have a maximum power output of 2kW, or thereabouts. If they >> successfully land and penetrate the ice and start pumping, and the water >> forms a volcano shaped dome, with an inclination angle of 0.1 deg, then it >> will take a approximately 161 days to grow a cone that is 3 meters high at >> the pump, and it will have a radius of 1.7km. It would then take about >> 107,000 of these to cover the ice sheet. That's a lot and probably far more >> than all the planes of the US strategic deployment force can deliver at the >> beginning of winter. Even if this is successful, a significant number will >> be released from the edge of the ice in summer, say 10%, so approximately >> 10,000 will float around in the ocean. >> >> Then there are known unknowns, these are: >> >> You do not know the angle that the water will settle on the ice, >> You do not know what shape the ice will form around the pump, it is likely >> to be a more complex and irregular doughnut shape. The mathematics behind >> this is extremely complicated, and after about a year's effort I managed >> only a partial solution before giving up. >> You do not know what effect the continual heat flow from the subsurface >> water being pumped onto the existing ice surface will have. In extremis, the >> pumps could cause the ice adjacent to them to melt so all they end up doing >> is pumping water into water. >> Even if there are solutions to all of these, there is the practical >> engineering matter of establishing the reliability of the pumps, especially >> when they are to operate in the Arctic winter which is both cold, dark and >> inaccessible. >> >> Then there are the unknown unknowns, these are: >> >> With the heat flow into the Arctic from the lower latitudes, then getting >> reliable and consistent ice formation, even in the depths of winter, may no >> longer be possible. >> Ice formed on the surface of existing ice is of a totally different >> structure to ice naturally formed by freezing downwards from the existing >> ice. This new ice may have a structure more like glass and be of low albedo, >> so in the summer it could act as a miniature greenhouse on the existing ice, >> which is also being warmed from below, thus accelerating the loss of >> existing ice when it is needed the most. This would be the worst case >> scenario. We prevent heat release in the winter and minimise albedo in the >> summer. >> It is now as big an issue to release heat from the planet as it is to stop >> more heat coming in. Given that the Arctic sea ice is now fatally doomed, an >> alternative is to accept this and smash up the remaining ice in the winter >> with icebreakers to allow the most rapid release of heat to space, at an >> estimated rate ~500W/m^2 >> >> This is not to say that we should not increase planetary albedo and find >> ways to release heat. We clearly must do it. I maintain that the safe >> temperature rise is less than 0.5degC above baseline, which we passed >> through in 1980. But we should be under no illusions that this is going to >> be simple and absent of scientific and engineering risks. >> >> Finally, and as you point out, carbon removal will be slow. The natural rate >> of removal is so slow as to not be measurable against CO2 emissions and the >> paleoclimate records that the AR6 is now taking more notice of indicates it >> will take about 250k years for CO2 to fall back to safe levels. So, as well >> as exploring all viable albedo and heat releasing mechanisms, we must >> immediately and simultaneously find ways to decarbonise. >> >> Kevin >> >> >> >> >> >> >> On Wed, Aug 11, 2021 at 12:16 PM 'Robert Tulip' via geoengineering >> <[email protected] <mailto:[email protected]>> >> wrote: >> I thought it was pretty bad that the IPCC report >> <https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf> >> states as its headline B.1 finding that "Global warming of 1.5°C and 2°C >> will be exceeded during the 21st century unless deep reductions in CO2 and >> other greenhouse gas emissions occur in the coming decades." >> >> It should rather state "Global warming of 1.5°C and 2°C will be exceeded >> during the 21st century even if deep reductions in CO2 and other greenhouse >> gas emissions occur in the coming decades." (my bold) >> >> As the NOAA AGGI report <https://gml.noaa.gov/aggi/> states, CO2 equivalents >> are now above 500 ppm. Emission reduction, technically defined, only reduces >> the future addition of GHGs to the system, and does nothing to remove the >> committed warming from past emissions. Leading scientists (eg Eelco Rohling) >> think past emissions already commit the planet to 2°C. >> >> Even a major program of carbon conversion, transforming CO2 into useful >> commodities such as soil and fabric, would do nothing to stop the escalation >> of extreme weather this decade. Carbon removal is too small and slow, >> despite having orders of magnitude greater potential cooling impact than >> decarbonisation of the world economy. >> >> My view is the only immediate solution is to brighten the planet. Albedo >> enhancement should start by pumping sea water onto the Arctic sea ice in >> winter to freeze and reduce the summer melt using wind energy (diagram >> attached). Marine cloud brightening is the next best option, followed by >> areas that need considerably more impact research such as stratospheric >> aerosol injection and iron salt aerosol. >> >> It is a disgrace that the IPCC seems to have entirely written off this whole >> area of response, with no scientific reasoning as to why. >> >> >> >> I understand that people find climate intervention for planetary restoration >> a rather mind-boggling idea and would prefer it were not needed. The problem >> is that extreme weather is steadily getting worse, and cutting emissions >> through the energy transition can do nothing to stop it. The overall issue >> is to define a scientific response to climate policy. That means relying on >> evidence to define the most safe and effective methods to support ongoing >> climate stability. Sadly AR6 squibbed that challenge. >> >> Much of the public policy relies on other factors as well as science. >> Notably this is about public perceptions rather than empirical assessment. >> But that means the climate activist community will no longer be able to use >> the mantra "the science says" to oppose geoengineering, as Michael Mann and >> Bill McKibben and others now do. >> >> I think the factors that could change public opinion quite quickly include >> the idea that immediate action to refreeze the Arctic is essential to >> maintain stability of main ocean currents. I was very perturbed to see the >> report last week on the slowing down of the AMOC Atlantic Meridional >> Overturning Circulation >> <https://www.theguardian.com/environment/2021/aug/05/climate-crisis-scientists-spot-warning-signs-of-gulf-stream-collapse> >> and Gulf Stream collapse, with potential disasters for the world economy >> and ecology. >> >> The linked press report suggested that decarbonising the economy is "the >> only thing to do" to prevent the AMOC from stopping. That is an absurdly >> unscientific opinion. It just fails to see that such natural processes >> require action at orders of magnitude bigger scale than the marginal effect >> of slowing down how much carbon we add to the air. >> >> If steps were taken to fully refreeze the Arctic Ocean, perhaps with the >> quid pro quo of including transpolar shipping canals >> <https://en.wikipedia.org/wiki/Transpolar_Sea_Route>through the ice, the >> scale would be big enough to stop the dangerous looming tipping points of >> accelerating feedback warming. Alongside AMOC, big problems such as polar >> methane release, wandering of the jet stream and melting of the Greenland >> Ice Sheet are also well beyond what decarbonisation can prevent. >> >> I really don't see any downside to such a freezing proposal, which should be >> an Apollo-type world peace project led by the G20. The climate activist >> community sees it as enabling a slower transition to renewables, but surely >> buying time in this way is entirely a good thing if it means we actually >> stabilise the climate? >> >> >> >> Robert Tulip >> >> >> >> From: [email protected] >> <mailto:[email protected]> >> <[email protected] >> <mailto:[email protected]>> On Behalf Of Robert Cormia >> Sent: Tuesday, 10 August 2021 4:32 AM >> To: chris.vivian2 <[email protected] >> <mailto:[email protected]>> >> Cc: Carbon Dioxide Removal <[email protected] >> <mailto:[email protected]>> >> Subject: Re: [CDR] IPCC AR6 Summary for Policymakers >> >> >> >> It took decades to get the public's attention about the clear and present >> danger of climate change, through extreme weather events, historic fires, >> and sea level rise. CDR is entering the dialog, slowly, it needs to >> accelerate. Newscasters could add a simple soundbite "net zero emissions and >> CO2 removal" as strategies, not just "clean energy and electric cars" How do >> we gain the public's awareness, much less attention, that putting a speed >> brake on emissions requires CDR, and restoring energy balance (addressing >> energy imbalance) is our best potential/feasible solution? >> >> >> >> -rdc >> >> >> >> On Mon, Aug 9, 2021 at 2:48 AM 'chris.vivian2' via Carbon Dioxide Removal >> <[email protected] >> <mailto:[email protected]>> wrote: >> >> In the IPCC AR6 Summary for Policymakers published today, see sections D.1.4 >> to D.1.6 on page 40 where it mentions CDR - >> https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf >> <https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf>. >> >> Chris >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Carbon Dioxide Removal" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/CarbonDioxideRemoval/d2ad5678-cf60-4af2-8968-3233344509f5n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/d2ad5678-cf60-4af2-8968-3233344509f5n%40googlegroups.com?utm_medium=email&utm_source=footer>. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Carbon Dioxide Removal" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/CarbonDioxideRemoval/CA%2B-rYQEG6iTG9qVC3GD-H5n6JdCBP%3Dwe3T24P-%2BUz6BR3E%2BhNg%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/CarbonDioxideRemoval/CA%2B-rYQEG6iTG9qVC3GD-H5n6JdCBP%3Dwe3T24P-%2BUz6BR3E%2BhNg%40mail.gmail.com?utm_medium=email&utm_source=footer>. >> >> >> -- >> 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] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/geoengineering/012c01d78ea2%2457f06f20%2407d14d60%24%40yahoo.com.au >> >> <https://groups.google.com/d/msgid/geoengineering/012c01d78ea2%2457f06f20%2407d14d60%24%40yahoo.com.au?utm_medium=email&utm_source=footer>. >> >> -- >> 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] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/geoengineering/CAE%3DUiezcG6_KoUsZMQN4jGfV1MA4EEVmmn_L_%2BHjqq3P6bok1g%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/geoengineering/CAE%3DUiezcG6_KoUsZMQN4jGfV1MA4EEVmmn_L_%2BHjqq3P6bok1g%40mail.gmail.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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