May I recommend to read Sam Carana’s blog (http://arctic-news.blogspot.com/2016/07/olivine-weathering-to-capture-co2-and-counter-climate-change.html ) on the olivine concept in your considerations. It is, after all, the ONLY process that has made a livable Earth for us, by capturing and storing practically all the CO2 that was ever produced by volcanoes in the past 4.5 billion years, and it is straightforward to increase its efficiency by mining, milling and spreading the olivine grains to capture CO2. Olaf Schuiling
From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of John Nissen Sent: dinsdag 23 augustus 2016 0:02 To: Benjamin Sanderson Cc: geoengineering; Andrew Lockley; P. Wadhams; Paul Beckwith Subject: Re: [geo] Michigan Scientists See Urgency for Negative Emissions | Climate Central Dear Benjamin, I was interested to read your paper, co-authored with Brian O'Neill and Claudia Tobaldi, about what it would take to achieve the Paris temperature targets [1]. There is clearly a limit of what can be achieved in emissions reductions, of around 50% per decade if 7% per year were to be achieved: “Although recent integrated assessment simulations have achieved 7% yr−1 reductions [Rogelj et al., 2015a<http://onlinelibrary.wiley.com/doi/10.1002/2016GL069563/full#grl54597-bib-0033>; Riahi et al., 2015<http://onlinelibrary.wiley.com/doi/10.1002/2016GL069563/full#grl54597-bib-0030>], this is only by massive transformation of the global energy system in the near term [Bertram et al., 2015<http://onlinelibrary.wiley.com/doi/10.1002/2016GL069563/full#grl54597-bib-0002>], achieved by rapid phase-out of existing infrastructure and by decoupling carbon emissions from economic growth [Rozenberg et al., 2015<http://onlinelibrary.wiley.com/doi/10.1002/2016GL069563/full#grl54597-bib-0035>].” Clearly negative emissions will be needed, but how soon and how much? I wonder about tackling the problem based on observations without having to rely on climate models which tend to have built-in assumptions. A logical approach is to ascertain the observed rate of global warming produced from the current level of climate forcing, and then see how much and how quickly that has to be reduced to achieve a given target, which is an integration of the rate over the next 84 years. The current underlying rate of global warming is generally agreed to be around 0.2°C per decade, based on the trajectory of the past thirty years (but neglecting this year when global warming forged ahead by 0.1 to 0.3 °C). The current forcing from CO2 is due to its excess in the atmosphere of 120 ppm, with a further 90 ppm CO2eq from other GHGs and black carbon, offset to some extent by SO2. In order to have a hope of achieving the <2°C target this century, the rate of global warming has to quickly halved from 0.2°C per decade to around 0.1°C per decade, which means halving the current forcing, e.g. by halving the excess levels of CO2 and other forcing agents in the atmosphere, in which case CO2 would need to be reduced from over 400 ppm down to around 340 ppm within about two decades. Similarly to achieve the <1.5°C would require a quartering of the current forcing. Do you accept this basic argument, because I cannot see how it could be fundamentally wrong? Now, the CO2 already in the atmosphere has a long lifetime. The rapid halving of excess levels of greenhouse gases and black carbon is feasible only if there is a drastic reduction in emissions (far faster than in RCP2.6) combined with aggressive and massive drawdown of CO2 to remove the gas faster than it is being emitted, probably only possible by increasing biomass in the sea as well as by using some land-based methods you have discussed. As I understand it, the main justification for attempting the <1.5°C target is to avoid tipping points. But the Arctic sea ice is already in a death spiral according to leading sea ice experts [2]. And the above reduction of climate forcing cannot be done quickly enough to prevent the Arctic Ocean becoming seasonally free of sea ice, adding considerably to climate forcing as well as risking abrupt climate change and sea level rise. Thus the Arctic needs to be cooled and sea ice preserved. This intervention must be made in addition to emissions reduction and CO2 removal. Professor Paul Beckwith describes these three actions as the legs of a three-legged stool, needed to prevent dangerous climate change. You can see an interview with him here [3]. I look forward to hearing your reaction to these arguments: whether you think they are valid or not. If they have any validity, interventions to remove CO2 and save the Arctic sea ice cannot come soon enough. Kind regards, John [1] http://onlinelibrary.wiley.com/doi/10.1002/2016GL069563/full [2] https://www.theguardian.com/commentisfree/2016/aug/18/ice-scientists-arctic-ice-disappearing-reduce-emissions-peter-wadhams [3] http://inhabitat.com/interview-paul-beckwith-on-the-jetstream-crossing-and-global-climate-emergency/ On Tue, Aug 16, 2016 at 7:22 PM, Andrew Lockley <andrew.lock...@gmail.com<mailto:andrew.lock...@gmail.com>> wrote: http://www.climatecentral.org/news/scientists-see-urgency-for-negative-emissions-20588 Michigan Scientists See Urgency for Negative Emissions Published: August 8th, 2016 By Bobby Magill ANN ARBOR, Mich. — When Sarang Supekar describes how he thinks global warming will have to be stabilized, he talks in terms of sucking a lot of carbon dioxide out of the air and in a very short timeframe. Supekar, a systems engineer at the University of Michigan, is part of a team developing a computer model that estimates how countries can stay within their carbon budgets, limiting their greenhouse gases so that the earth does not warm beyond the 2°C (3.6°F) threshold. His research, which is ongoing and has not yet been published, is suggesting an increasingly dire situation: Countries may have only until 2026 to begin retiring most old coal-fired power plants and replacing them with 100 percent renewable power sources, or the globe is likely to blow through its carbon budget and exceed 2°C of warming. What happens if countries miss that target? “Then we have no option than to remove the CO2 we have already emitted,” Supekar said. However, nobody is certain if removing carbon dioxide from the atmosphere — something called “negative emissions” — to help stabilize the climate is possible or feasible on a mass scale. The program Supekar works under at the University of Michigan — Beyond Carbon Neutral— is one of several university programs across the country investigating potential ways of taking large-scale negative emissions out of the theoretical realm and into the real. The negative emissions technology that exists today is in its infancy. Much more research on carbon dioxide removal is necessary, and understanding the costs is paramount because the technology will take time to develop and scale. Mounting research suggests that negative emissions may have to be a major part of any global strategy to stabilize the climate because simply slashing carbon dioxide emissions likely won’t be sufficient. That’s something that the Intergovernmental Panel on Climate Change acknowledged when it factored negative emissions into some of its climate stabilization scenarios in its Fifth Assessment Report in 2014. A National Center for Atmospheric Research studypublished in July showed that halting global warming at 2°C is likely to require carbon dioxide to be removed from the atmosphere on a large scale by the second half of this century. But researchers say the world would benefit by developing negative emissions technology as soon as possible. Scientists are studying how to make carbon-dense forests absorb more carbon dioxide from the atmosphere as a way to create negative emissions. Credit: Francis Eatherington/flickr “I think we should not make the mistake to only look at the second half of the century,” said Sabine Fuss, a climate change mitigation researcher at the Mercator Research Institute on Global Commons and Climate Change in Berlin. “We’re talking about a huge infrastructure that needs to be developed in time and we need to be in a position to make use of it, too, because if we continue to emit as much (carbon dioxide) as we do currently, then negative emissions won’t help us either to achieve ambitious climate targets.” Scientists are studying many different ways of carbon dioxide removal, including growing trees for biomass electric power production and then capturing and storing the resulting emissions. Other strategies involve planting large forests across the globe, and altering soil management to increase the amount of carbon it can store. Mark Barteau, director of the University of Michigan Energy Institute and co-founder of Beyond Carbon Neutral, said the one of the biggest challenges to developing negative emissions technology is overall lack of research funding and only recent recognition that it may be necessary at all. With the global emphasis on emissions cuts, scientists need to think more strategically about how to generate interest in negative emissions so the technology can be developed sooner — the primary goal of Beyond Carbon Neutral, Barteau said. Researchers at Beyond Carbon Neutral are developing both negative emissions technology and thinking about ways it could be implemented on a broad scale. Supekar’s model, for example, focuses on what it might look like to build large “negative power plants” — renewable energy-powered installations that would directly remove carbon dioxide from the atmosphere and store it someplace. He said the model suggests that many thousands of negative power plants would be needed globally, requiring a massive new electric power and carbon storage infrastructure whose cost could range into the quadrillions of dollars. “Removing emissions using direct air capture as a large-scale mitigation approach is likely to be more expensive by at least two to three orders of magnitude relative to preventing our emissions in the next 10 years,” Supekar said. Beyond Carbon Neutral scientists are also researching ways that forests can be enhanced to store more carbon dioxide. Forests can only create negative emissions if they increase the rate at which they absorb carbon dioxide from the atmosphere and keep it locked up in the ecosystem’s roots, tree trunks and soil, saidJohn DeCicco, a University of Michigan climate mitigation researcher and co-founder of Beyond Carbon Neutral. >From a carbon cycle perspective, once plant leaves have removed carbon dioxide >from the atmosphere through photosynthesis and stored it in tree trunks and >roots, “we are as ahead of the game as we can ever be with respect to the >atmosphere,” he said. As part of the Beyond Carbon Neutral program, Nina Lin, a chemical engineering professor at the University of Michigan-Ann Arbor, is researching how microbes can help store carbon dioxide from the atmosphere. Credit: Bobby Magill/Climate Central So the key may be to enhance the rate at which forests absorb carbon — something Beyond Carbon Neutral scientists are studying on private forestlands in northern Michigan. The solution is simple: “Grow more trees better and keep them parked longer, DeCicco said. In the U.S., the more than 500 million acres of federal public lands also present a major opportunity for negative emissions, DeCicco said. With the federal government as the single land manager of such a vast area of land, ecosystems could be optimized for enhanced carbon storage, he said. “Instead of a big effort to promote biofuels, that should be completely abandoned from a scientific point of view and we need to be making a full-court press to protect and preserve and expand forests, wetlands, natural grasslands and natural ecosystems that are carbon sinks,” DeCicco said. Barteau said there are many unanswered questions about how carbon can be removed from the atmosphere, but it’s urgent that those questions be answered sooner than later. “Start now,” he said. “We may wish we could throw a switch in 2040 or 2050 to turn it on. 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