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Comments 105001 to 105050:

105001. RSVP at 00:04 AM on 10 November 2010
        Climate change from 40 million years ago shows climate sensitivity to CO2
        CBDunkerson #63 "Look, you said that the only way that Mars could have had liquid water in the past was if the Sun had been hotter then. I have shown that this is incorrect" I agree (for a change ;) ), please check the following for more plausible explanations... http://en.wikipedia.org/wiki/Comet_Hale-Bopp "Hale-Bopp's orbital position was calculated as 7.2 astronomical units (AU) from the Sun, placing it between Jupiter and Saturn and by far the greatest distance from Earth at which a comet had been discovered by amateurs.[10][11] Most comets at this distance are extremely faint, and show no discernible activity, but Hale-Bopp already had an observable coma.[5]" Now, for any of this to have significance in the discussion, you have to assume that the coma is caused by melted water, (which is not necessarily the case as there are other more volitile components), however, comets generally get noticed before they pass within Earth's orbit, and they do contain a lot water. Aside from what has been brought up in all these earlier comparisons iwith Mars, the rotation and tilt of planets might be easier to assume having altered over time and having affect on climate, than the Sun's brightness. On the link about Hale Bopp, it says, "Comet Hale-Bopp's activity and outgassing were not spread uniformly over its nucleus, but instead came from several specific jets. Observations of the material streaming away from these jets[42] allowed astronomers to measure the rotation period of the comet, which was found to be about 11 hours 46 minutes.[43]" Then you data on the rotation and tilt of Mars itself... http://www.universetoday.com/14889/mars-rotation/ "For all of its differences, here’s one situation where Mars is very similar to Earth. Mars’ rotation is 24 hours, 39 minutes, and 35 seconds. In other words, Mars only rotates 39 minutes more slowly than Earth." http://www.universetoday.com/14894/mars-tilt/ "Astronomers know that the current tilt of Mars’ axis is just a fluke. Unlike Earth, the planet‘s tilt has changed dramatically over long periods of time. In fact, astronomers think that the wobble in the tilt might help explain why vast underground reservoirs of water ice have been found at mid-latitudes, and not just around the planet’s poles. It’s possible that in the distant past, Mars was tilted at a much more extreme angle, and the ice caps were able to grow across the planet. When the tilt was less extreme, the ice remained, and was covered by a layer of dust." If I have to make a point (based on all of the above), it would be that even if the mean temperature of the Earth were supposely 33 degrees colder without CO2 in the atmposphere, there would still likely be portions of the Earth with temperatures high enough to melt water.
105002. CBDunkerson at 23:12 PM on 9 November 2010
        Ice-Free Arctic
        Heh... obviously I meant 'leveling off BEFORE hitting zero'. The standard hypothesis, as articulated by Riccardo in the article, is that ice loss is being driven primarily by air temperature rise from global warming and ice-albedo feedback. As the amount of ice declines the change in albedo from any further decline becomes smaller and thus there would be 'diminishing returns' and a long period of slowly declining sea ice. Obviously the volume trend, as inferred by PIOMAS, tells a different story unless it suddenly changes course radically some time in the next few years OR the PIOMAS results are off. I don't think the latter is likely based on verifications against other data sources (as I mentioned previously and Artful Dodger has just explained in more detail). However, with Cryosat-2 now online and the current volume trend only a few years from hitting zero I think we'll have a clear answer some time relatively soon.
105003. Tony Noerpel at 23:11 PM on 9 November 2010
        Skeptical Science moving into solutions
        Mike thanks for that link. I agree with the general sentiment to keep the discussion about the problem space separate in some way from the solution space. Also there are several dimensions to the solution space. The first is simply the technology, itself, from caulking to fusion. The second is the economic discussion, what we can afford to do and what we cannot afford not to do. The third is the social problem - how to convince society to implement the technology and that they cannot afford not to do it. The third may be the most difficult.
105004. Pete Dunkelberg at 22:54 PM on 9 November 2010
        Ice-Free Arctic
        CBDunkerson #43 ... we should know in the next few years whether this 'fast decline' scenario or the 'leveling off' prediction is correct. Unless you believe in negative ice, leveling off is a sure bet. :)
105005. adelady at 22:51 PM on 9 November 2010
        Antarctica is gaining ice
        Did you look at the graphs showing increasing loss of land ice? Or not.
105006. CBDunkerson at 20:24 PM on 9 November 2010
        Climate change from 40 million years ago shows climate sensitivity to CO2
        On the 'Sun may have not been dim in the past' link... in addition to the moderator's point about the article actually exploring mechanisms for the OPPOSITE argument (that the Sun WAS dim) it should be noted that the article was written in 1987. The whole 'the sun may not have been much dimmer in the past' idea which the article describes as "highly speculative" back then would now, with the benefit of 23 years of additional research, fall into the category of 'implausible fiction'.
105007. Artful Dodger at 20:17 PM on 9 November 2010
        Ice-Free Arctic
        Despite some of the comments above, PIOMAS has already undergone extensive Model Validation. Long before CryoSat-2, NASA's ICESAT mission provided 5 years of sea ice thickness data (2003-07). Researchers also used data from US Submarine cruises, and moored Buoy Arrays to have 3 independent sources of data. More details on the model, assimilation procedures and validation results can be found here.
105008. CBDunkerson at 20:09 PM on 9 November 2010
        Ice-Free Arctic
        Pete Dunkelberg #41: "Note that heat transport into the Barents Sea has an influence out of proportion to its fraction of the Arctic heat budget." Aha... precisely the theory I was going on back in comment #10. There is clearly something major missing from the Arctic sea ice prediction models and this seems like a strong candidate to me. It also suggests a very different 'end game' for the Arctic sea ice than current models... because if a large portion of the ice loss is being driven by influx of warmer water there should be no 'slowing down' of the decline. Indeed, it should just keep accelerating as less ice = stronger currents = more warm water imported. Given that there was only 4000 km^3 of ice left this past September (average for the month) and it has been dropping about 1000 km^3 per year for the past decade we should know in the next few years whether this 'fast decline' scenario or the 'leveling off' prediction is correct.
105009. esjope at 19:50 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Marcus @ #29: Our company produces biodiesel and bio-oil from waste fat and oil. It is easy when you have a good point source of raw material. But collecting small amounts from here and there ruins both the economy and energy balance of the fuel production. Fast food industry is already (at least in Europe) producing fuel from their waste oil. Collecting the oils from households is not an option at the moment. Producing fuel from waste has a very good energy balance and is definitely a part of the solution.
105010. JMurphy at 19:38 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Something coming out of MIT recently gives a pointer as to how solar energy can (and, no doubt, will) be stored more efficiently and effectively : Catching the sun’s heat - Storing thermal energy in chemical form has the potential to make it indefinitely storable and transportable. "This is the thermo-chemical approach, in which solar energy is captured in the configuration of certain molecules which can then release the energy on demand to produce usable heat. And unlike conventional solar-thermal systems, which require very effective insulation and even then gradually let the heat leak away, the heat-storing chemicals can remain stable for years."
105011. Bern at 18:34 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Phila @ #28: It already *has* happened - if you consider the lack of regulation of the finance sector and the resulting economic chaos of the last few years... Marcus @ #29: Wikipedia suggests that in the US, at least, waste vegetable oil could substitute for as much as 1% of fossil oil consumption. Only a very small part, but still, 1% of however many $billions is a lot of potential value. (~20million barrels per day, at ~$80/bbl, = $1.6billion per day, so 1% of that would be $16m per day, or $5.8billion per year worth of oil)
105012. Norman at 16:30 PM on 9 November 2010
        Climate change from 40 million years ago shows climate sensitivity to CO2
        Also not to forget this one. Sun may have not been dim in the past.
        Moderator Response: I don't understand your point. The article you linked to says that the notion that the Sun was not dim in the past "remains highly speculative." The article focuses instead on describing several mechanisms that could have made the Sun dim.
105013. Pete Dunkelberg at 16:26 PM on 9 November 2010
        Ice-Free Arctic
        Oops. The title of Irina Mahlstein's dissertation is Ocean heat transport as a cause for model uncertainty in projected Arctic warming.
105014. Norman at 16:25 PM on 9 November 2010
        Climate change from 40 million years ago shows climate sensitivity to CO2
        #62 Tom Dayton Thanks for linking the slide show. Some of the slides remained blank. Here is a graph for you that shows little relationship between CO2 and temp over the eons. Not much of a match between CO2 and Temp. Faint Young Sun and Paradox. During the faint Sun, the CO2 levels were low.
        Moderator Response: Regarding your first link, a simple correlation between only CO2 and temperature over the entire history of the Earth of course will not be straightforward, because CO2 was not the only forcing of climate during that entire period, and also acted as a feedback. But recently CO2 has been the dominant forcing; see "There’s no correlation between CO2 and temperature," and for background see "CO2 is not the only driver of climate," where you should be sure to click the Intermediate tab. Regarding your second two links, I don't understand your point.
105015. Pete Dunkelberg at 16:19 PM on 9 November 2010
        Ice-Free Arctic
        After reading Neven, google up this dissertation Ocean heat transport as a cause for model uncertainty in projected Arctic warming [large pdf] and especially Chapter 2, Ocean heat transport as a cause for model uncertainty in projected Arctic warming. Note that heat transport into the Barents Sea has an influence out of proportion to its fraction of the Arctic heat budget. Further study of this heat transport looks to be a key to reducing the uncertainty of Arctic sea ice projections.
105016. Norman at 16:11 PM on 9 November 2010
        CO2 effect is saturated
        Climate4you has graphs that may conflict with this statement. "So we have multiple lines of empirical evidence for an enhanced CO2 greenhouse effect. Satellite measurements confirm that less longwave radiation is escaping to space. Surface measurements detect increased longwave radiation returning back to Earth at wavelengths matching increased CO2 warming. And of course the result of this energy imbalance is the accumulation of heat over the last 40 years." Graph which indicates that longwave radiation is not following CO2 increase. Explanation given to the above graph: "For the equatorial region, the diagram above suggests a certain chain of events, indicating the existence of a mechanism regulating the surface temperature: Periods of surface warming appears initially to be associated with decreasing outgoing longwave radiation (OLR). After some surface warming, OLR then stops decreasing and instead begins to increase, and after a while, surface air temperature then begins to decrease, etc. This chain of events is clearly illustrated by, e.g., the time period around the 1998 El Niño event (diagram above). Part of the explanation of the above succession of events might be that tropical surface warming leads to enhanced atmospheric convectional transport of heat to high levels of the atmosphere above the Equator, resulting in enhanced longwave radiation at the top of the atmosphere. This, in turn, eventually leads to surface cooling, which results in reduced atmospheric convection, etc. Also the potential connection to variations in tropical sea surface temperatures and the tropical cloud cover is interesting, and should be considered in a more detailed analysis." This graph shows poor correlation of CO2 to Longwave raditation. This graph questions the conclusions of the Skeptical Science.
        Moderator Response: Your first link is broken.
105017. Phila at 15:37 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        #28 Usually, when Climate Change skeptics run out of valid arguments, they use the "well we can't do anything, because it will *wreck* the economy" argument. Which tends to be the stock response to every form of regulation among people of that mindset. Addressing the ozone hole was supposed to send us back to the Stone Age, too, as was nearly every regulatory approach to pesticides. (Though to be fair, it really would be terrible if some shortsighted group of self-styled "experts" wrecked the economy by taking enormous risks based on an opportunistic misinterpretation of dubious data. Let's pray it never happens!)
105018. Pete Dunkelberg at 15:31 PM on 9 November 2010
        Ice-Free Arctic
        For the first time, both the northwest and northeast passages offered smooth sailing this summer. I don't know what's up with that first graph, but look for an essentially ice free Arctic winter before 2100 unless we stop burning carbon.
105019. Marcus at 14:12 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Here's a quick question-how much vegetable oil do you think the Fast Food industry goes through in a week? How about a year? How much waste vegetable oil do households usually generate every year? Right there we have an immediate, & viable, source of bio-fuel. All you need is methanol & a little bit of heat & you have the perfect substitute for petrol. The Germans already do it, & sell it at petrol stations alongside conventional petrol & diesel.
105020. Marcus at 14:10 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Unfortunately, Stephen Baines, I've noticed that they're often one in the same. Usually, when Climate Change skeptics run out of valid arguments, they use the "well we can't do anything, because it will *wreck* the economy" argument. Yet according to what I've read, Germany has achieved massive increases in its levels of renewable energy, yet electricity bills-for the average family-were only $12/month more in 2008 than they were back in 1998-hardly an economy wrecking increase! Indeed, I halved my own CO2 emissions just by becoming more energy efficient-& ended up saving myself roughly $100 per quarter. Then I halved it again by switching to a 50% Green Energy Scheme-yet I'm still paying less for my electricity bills than I was 10 years ago! My point is that, even in the absence of technological improvements in the future, the solutions to our problems are not going to be *nearly* as painful as the skeptics would have us believe-& probably much less painful than adaptation to a warmer climate!
105021. Marcus at 14:01 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Oh, & though its somewhat out of date now (at least in terms of raw technology), I'd recommend people here read the book "The Big Switch" by Gavin Gilchrist. An excellent expose on how Australian Governments (primarily Labor) stymied even limited attempts to "Green" our energy grid throughout the '80s & 90's-just to keep the existing electricity industry happy (most of which was still State owned at the time the book was written).
105022. Marcus at 13:56 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        As far as Bio-fuels go, just look no further than High Density Vertical Algal Biomass. The CO2 sequestration density of certain types of algae is absolutely phenomenal. Also, once you've extracted the 50% lipid content to make bio-diesel, you can gasify what's left & burn the resulting gas for electricity-effectively doubling the amount of kw-h's of electricity per tonne of CO2 generated. Methane Gas derived from natural sources-like landfill, sewerage, farm & forestry waste, to name just a few-could also be an excellent source of relatively low Carbon electricity (& heating/cooling), especially if combined with things like Thermal Storage (subjecting methane to varying degrees of heat-from the sun, say-can either boost the energy potential of methane by around 20%, without thermal decomposition, or even cause it to break down to by-products that can be later re-reacted to get back the stored heat) & Algal bio-sequestration. Of course, another benefit of many renewable energy technologies-including bio-gas-is that you can build them on a much smaller scale, & built up from multiple smaller subunits. This has the double benefit of reducing-or eliminating-the almost 12% of electricity lost through transmission & distribution, & allows you to scale the electricity supply back to meet the much lower, off-peak levels of demand. Other things we could look at are placing solar panels on more of our streetlights-& making those streetlights more energy efficient. A properly hooded streetlight can cast 30% more illumination than a light of identical wattage that is unhooded. Also, streetlights converted from High Pressure Sodium to Low Pressure Sodium (or is it the other way around-I must look that up!) can get higher numbers of lumens from an identical number of watts. Back on the energy supply front, more use of Co-generation would also help to lower the CO2 footprint of our economy! I know some people have suggested nuclear power, but I think this is a fools errand (short of some massive, *massive* breakthroughs). Even if we ignore the long-lived waste by-products at both ends of the nuclear cycle, there is the simple fact that uranium reserves are only expected to last til the end of the century-even at *current* levels of use. Proponents have said that global nuclear capacity would have to *triple*, just to achieve a 15% reduction in CO2 emissions!
105023. Riduna at 12:11 PM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Stabilising CO2 emissions really means 2 things – using electricity more efficiently and replacing fossil fuels with other ways of generating electricity. While there is scope for improving the efficiency with which we use electricity, something which can be achieved by increasing its cost to consumers, a major drawback is the present inability to store it. Development of a light, durable and affordable battery able to hold a significantly larger charge than can present batteries must is achieved. When this is done, it will be possible to replace fossil fuel used by vehicles with electricity. It will also be possible to store electricity required for domestic use and re-charge batteries during off-peak periods or from more efficient pvc’s. It will also be possible for national grids to draw on this storage to meet peak demand Generating electricity by using fossil fuels, particularly coal, has first to be stabilised, second reduced and third stopped, while meeting the energy needs of an expanding global economy. Ability to achieve these stages in Australia is assisted by use of geothermal energy to generate base load power but few other countries have easy access to this source. Others must depend on solar energy as a means of replacing fossil fuels or go nuclear with all its waste problems. Solar technology in its present form generates electricity directly using pvc arrays or thermally, concentrating solar energy onto heat storing materials. PVC’s are inefficient and as noted above, with insufficient ability to store electricity they do not provide a viable alternative to fossil fuels. Concentrator technology, particularly for countries in the tropics and semi tropical areas does offer an alternative to fossil fuels but until improved not a cheaper alternative. Until we tackle development of electricity storage devices, more efficient pvc’s and improved concentrator technology, we are unlikely to make significant inroads into replacing fossil fuels, the major source of greenhouse gases.
105024. michael sweet at 10:24 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        One thing to keep in mind is these projections are very long term and the scientists do not know what will work. It is very unlikely that the 16 wedges proposed will actually be the ones that work out best. Maybe wind will end with 5 wedges and solar thermal only 1. The point is that a reasonable scenario can be put together. Every 5 years the wedges should be adjusted to reflect what has been learned. Additional adjustments will have to be made to counter Ann's issues. As time passes we will learn what needs to be done in the next decade. First we have to get started. Spain and Germany are showing us ways to get started. From their experience we will learn better what works and what doesn't.
105025. renewable guy at 10:19 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Over at Climate Progress there was a lot of discussion about carbon wedges. On cars and biofuels. If society adapts fuel efficiency as a cultural value, 60 to 100 mpg won't be a huge problem. At the moment in the United States leading that charge is political suicide. Even boosting efficiency standards are being resisted. The progressive X prize saw a winner who got 100 mpg with a one cylinder engine, it can go 100 mph, carry 4 people, designed by formula 1 engineers. In production it will sell in the twenty thousands. From that point of view the x prize was a success. With cultural change anything can be done. Easier said than done though.
105026. jcwinnie at 10:18 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        I am skeptical about such credence to CCS (Carbon Capture and Storage). Even if possible (a very big IF) it reflects little change to a system destroying life on the planet as we know it. Particularly with coal, it is an insidious misdirection, or have we forgotten the recent coal ash spills? There is a greater concern. This article jumps ahead without consideration of a critical parameter: when? If the cavalry arrives after the massacre, all they can do is bury the bodies. Quite a coincidence that the time frame chosen by PS04 approximately equals how long U.S. policy makers have delayed since nations convened and acknowledged the problem.
105027. forensicscience at 10:13 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        China has no alternate energy sources to the USA, it needs all of them. 16 wedges is a vast undertaking.
105028. Stephen Baines at 09:36 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        I have a more rhetorical comment, which may be important as this is the first post in an important (IMO) new direction for the site. I wonder if it's maybe more sensible to refer separately to climate skeptics and solution skeptics rather than lumping them together. Otherwise, your first sentence implicitly equates skepticism about the solutions to climate change with skepticism about the science concerning the effects of CO2 on climate. Uncertainty about how the problem should be solved is not trivial -- it requires breaking new ground technologically and in terms of political cooperation. However, whether one thinks those challenges are duanting or not should have absolutely no bearing on the veracity of the scientific evidence for climate change. We should not perpetuate the confusion by using the same term for these two positions, even if it is true that many that are initially solution skeptics decide to become climate skeptics as a result. It will only hinder the focus of the discussion...
105029. Argus at 09:34 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Miles??? Per gallon??? What happened to metrics? Are we really going to move into the future with a mixture of unrelated units, used since the Middle ages or since the Romans; units that were based on fingers, feet, baskets, barrels, the weight of a coin or a seed, and what have you? The metric system was developed 200 years ago, with the purpose of standardizing all units in different fields, and making them connected to each other in logical ways. Let us use 'The International System of Units'! The US is now the only nation in the world that does not officially use the metric system (with the possible exception of Burma and Liberia).
105030. dana1981 at 09:32 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Fair enough KeenOn350, but the wedge refers to a goal nearly 40 years in the future. I wouldn't write it off just yet.
105031. KeenOn350 at 09:20 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        @ Dana1981 re: "biofuels coming from non-food crop sources." I defer here to Fridley's expertise - he suggests that experimental non-food crop sources are a long ways from being scaled up to commercial use - and other factors come into play, such as water use, even for non-food crop sources. The referenced video is quite long - but chock full of information.
105032. Rob Honeycutt at 09:17 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        forensicscience.... The folks in power in China are no dummies. They clearly see that fossil fuel use is not going to carry them through the rest of the 21st century. Oil is going to be a dwindling resource during a period where they are continuing to try to bring their entire nation up to first world standards. The ONLY way they can to that is by getting off carbon based energy. Honestly, the issue is not just climate change. It's population, resource availability, energy demand, pollution issues, geopolitical issues... all oriented toward a massive crisis. Like it or not, one of the big advantages China has right now is their political system. Their government is not beholden to established energy interests. Ours, in the US, is.
105033. dana1981 at 09:07 AM on 9 November 2010
        Skeptical Science moving into solutions
        Karamanski - yes, most Skeptical Science articles will probably still center around climate science, as opposed to climate solutions. We'll just have some solutions articles and rebuttals interspersed in there.
105034. forensicscience at 09:01 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        China may be investing in it all but its still using increasing amounts of fossil fuels too and that is one of the big issues, growth. Growth is measured by the log2=70 so divide any annual growth rate into 70 and you get the doubling time. So lets say presently the annual growth rate of fossil fuel usage is 2% then in 70/2=35 years we will have doubled our fossil fuel usage and more than likely our emissions to 60 billion tonnes of Co2 per annum up from 30 today. Add it all up and in just 35 years time (2045) we will have added another 1.5 trilion tonnes leaving around half of it in the atmosphere. Thats is a lot more than is presently there by humans. Combating it is a time issue as well as a political, economic and technological one. Any unproven technology not demonstrated to be scalable to industrial proportions cant be viable, thats leaves csp, wind and nuclear really at the moment.
105035. mothincarnate at 08:58 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Great write-up Dana, One thing worth mentioning as it relates to both 14 and 15 - Cleveland and Townsendm (2006) did an interesting study where they fertilised rainforests with phosphorus (many rainforests are have very limited P). This lead to much of the carbon in litter being lost through CO2 emissions rather than being used by the forest or stored. P fertilisation of agricultural land adjacent to forest has the potential to alter mineral cycles and cause P fertilised forests to become net emitters rather than sinks of CO2.
105036. Karamanski at 08:54 AM on 9 November 2010
        Skeptical Science moving into solutions
        Will Skeptical Science still post articles about global warming itself even though the blog is shifting to the solutions of global warming? Because I think this is a brilliant blog about the science of climate change.
105037. dana1981 at 08:43 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        forensicscience - China is investing in green tech more than the USA right now. They see the writing on the wall.
105038. forensicscience at 08:34 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        All those wedges 16 of them required concurrently to stabalise at 450 ppmv is unlikely considering that a lot of car enriching countries such as China are not doing it now but could with persuasion but capatalism states that you can make money and drive what you like. Can a 2 tonne car do 60 MPG
105039. forensicscience at 08:31 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Dana1981, Shale gas is a pipedream regardless of what is said. Its just not sound science to suddenly up the reserves based on a dubious method drilling.
105040. forensicscience at 08:30 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Ann, what you are saying is not very reasonable to be fair. Its the we cant do it attitude. Coal can easily go technologically but its the economics and politics that are the issue. Lots of power in coal, its an old industry with lots of political know how and finance to see that its interests are met.
105041. OPatrick at 08:01 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        I'm sure many on here will already have come across David MacKay's Sustainable Energy - without the hot air. He gives a number of scenarios showing different combinations of sustainable energy solutions. I'd be interested to hear how people think this stands up. The PriceWaterhouseCooper's report showing how Europe could be powered entirely by renewable energy by 2050 is also interesting reading.
105042. dana1981 at 07:49 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Ville - assuming that coal power prices will drop is unrealistic. Ville and forensicscience - the reason natural gas prices have been dropping is that more reserves have been identified, particularly from unconventional sources like shale gas. KeenOn350 - that's why I specifically made a note about biofuels coming from non-food crop sources. apsmith - good point, thanks. I just used the numbers in PS04, but obviously that's now 6 years old. Ann - the wedges have to assume some sort of baseline, so they assume all else is equal. Of course if not all else is equal, then the numbers have to be adjusted accordingly. But since we can't forsee every change in response to a wedge action, and human responses are not very predictable, the simplest and best assumption is 'if all else is equal', and in the future we can adjust the numbers as necessary.
105043. Ann at 07:42 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        I must admit in this area I am very skeptical indeed. The “wedges” idea is based on the wrong assumption that you can change one parameter of the system and keep all the rest constant. I am frankly amazed that climate scientists, who are used to work with complex, chaotic mathematical models seem to think that simple sums suffice to calculate the effect of drastic economic and technical measures on human society. Mind you (before someone reads me wrong), I am not claiming at all that we cannot achieve some of the points that are mentioned. We could for instance produce a substantial amount of biofuel to replace fossil fuels. What I am doubting is the effect such measures will have against climate change, because I think that next to the desired effect (reduce CO2 emissions) there will be a myriad of unforeseen and undesired effects that may very well render the whole operation useless. My skepticism is not entirely unfounded. We have already seen at least one result of this simplistic thinking: the massive promotion of biofuels (particularly in Europe) has lead to rapidly increasing deforestation in many parts of the world, thereby negating any positive effect that could have resulted from using biofuels in the first place. Another example: “improved fuel economy. One wedge would be achieved if, instead of averaging 30 milesper gallon (mpg) on conventional fuel, cars in 2054 averaged 60 mpg, with fuel type and distance traveled unchanged.” The question that immediately comes to mind is: Did improving fuel economy of cars in the past reduce CO2 emissions ? Between 1975 and 1985 the fuel economy of an average car doubled, from 13,5 to 27,5 miles per gallon. Did this reduce overall CO2 emissions ? Of course the trick is the phrase “with fuel type and distance traveled unchanged”. Unfortunately, this is not what is going to happen. If people pay less for their fuel, they will in general drive travel longer distances. Such side effects must be taken into account, instead of setting unrealistic preconditions. I am not advocating despair, but you need more to convince me than this kind of 1+1=2 logic. Climate scientists wouldn’t dream of linearly adding up climate forcings and feedbacks to arrive at a predicted climate change – at least I hope so. Why use this simplistic logic when trying to predict how human society reacts to certain measures ? To evaluate the impact of the proposed measures on human society, a mathematical model should be constructed that is in every way as complex as any climate model. The relevant parameters are at least: population growth, economic rules like supply and demand, total available global and local resources (e.g. food and energy, with food being heavily dependent on energy), etc., economic growth, ecological footprint, government subsidies etc. This should give us some insight in the interactions that exist between abovementioned parameters. And then you could start truly evaluating the actual effects the proposed actions may have on CO2 emissions.
105044. muoncounter at 07:42 AM on 9 November 2010
        Climate change from 40 million years ago shows climate sensitivity to CO2
        #50: "It is fully accurate to say that cooling oceans CAUSE lower CO2 levels. Much like warming oceans CAUSE higher CO2 levels." Not so fast. If you expect warming oceans to release CO2, then why do we see increased acidity in today's warming oceans? The oceans are absorbing carbon dioxide (CO2) from the atmosphere and this is causing chemical changes by making them more acidic (that is, decreasing the pH of the oceans). ... Calculations based on measurements of the surface oceans and our knowledge of ocean chemistry indicate that this uptake of CO2 has led to a reduction of the pH of surface seawater of 0.1 units, equivalent to a 30% increase in the concentration of hydrogen ions. -- Raven et al 2005 Similarly, warming temperature and increasing ocean acidity during the Eocene --> oceans absorbing CO2. During the most prominent and best-studied hyperthermal, the PETM, the global temperature increased by more than 5C in less than 10000 years. At about the same time, more than 2000 Gt C as CO2 -- comparable in magnitude to that which would occur over the coming centuries -- entered the atmosphere and ocean. -- Zachos 2008 CO2 entering just the atmosphere could be ocean outgassing. But entering both ocean and atmosphere hardly indicates that the ocean is giving up the gas. A controlling factor is the 'carbonate compensation depth,' which can vary considerably with both ocean temperature and acidity. Tripati et al 2005: ... report evidence for synchronous deepening and subsequent oscillations in the calcite compensation depth in the tropical Pacific and South Atlantic oceans from 42 million years ago, with a permanent deepening 34 million years ago. ... suggest that the greenhouse–icehouse transition was closely coupled to the evolution of atmospheric carbon dioxide, and that negative carbon cycle feedbacks may have prevented the permanent establishment of large ice sheets earlier than 34 million years ago.
105045. scaddenp at 07:37 AM on 9 November 2010
        Keep those PJs on: a La Niña cannot erase decades of warming
        TIS - I see the "oceans are causing it" argument again. If the oceans are cause, then you need to look at the surface temperature trend from say 1975 and reckon what means as an amount of an energy transfer from the oceans (as you see in small scale in ESNO). To prevent a violation of first law, what must that mean for OHC? Got a single published paper that presents a thermodynamically sound model for accounting for that trend by ocean cycles?
105046. michael sweet at 07:36 AM on 9 November 2010
        Skeptical Science moving into solutions
        I think the division of the Skeptical Science site lends itself to this type of discusion. People read the threads that they are interested in. The moderators will have to learn how to keep the discusion on track and not let one person overwhelm everyone else. There will be a learning curve but it sounds good to me.
105047. scaddenp at 07:28 AM on 9 November 2010
        Climate change from 40 million years ago shows climate sensitivity to CO2
        TIS - the paper is about a transient event at 40my. The plate reconstruction in the paper infers drake strait had not opened and I am not aware (but could be uninformed) of evidence for persistent ice sheet in the antarctica at that time. I dont see really what you points have to do with this paper. However, you claim that development of ice sheets in antarctica would reduce CO2 and cool the ocean (presumably you mean ocean cooling reduces CO2??). I wonder what you think the mechanism for this is? Ice sheets definitely increase albedo but if you think changes to GHGs are an insignificant element in determining climate, then I am interested to you how the ice sheet development cools the global oceans. Can you make the arithmetic add up? Warming oceans can cause higher CO2 levels (amplifying warming - that is what "sensitivity" is about) but you do know that the elevated CO2 levels at present are from fossil fuel and not from out the ocean?
105048. KeenOn350 at 07:22 AM on 9 November 2010
        Skeptical Science moving into solutions
        I'm inclined to agree with BillWalker - SS as it is now is a very valuable reference site, in part because it is apolitical. Solutions get complicated - even the question of their " scientific validity". Maybe a related site would be a good idea.
105049. apsmith at 07:11 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        Some of the numbers are out of date. For example on wind, total world installed capacity at the end of 2009 was 158 GW, of which almost 40 GW was added in that year. That's a factor of 12, not 50, to get to 2000 GW. And by now it should be down to a factor of about 10, not 12. See here for this data: http://www.renewableenergyworld.com/rea/news/article/2010/02/global-wind-installations-boom-up-31-in-2009 I think a better source than Pacala and Socolow are the various McKinsey studies that also consider the economics, rather than just technical feasibility: http://ww1.mckinsey.com/clientservice/sustainability/service.asp in particular their GHG abatement cost curves: http://ww1.mckinsey.com/clientservice/sustainability/Costcurves.asp and this 2009 report on "Pathways to a low carbon economy": http://ww1.mckinsey.com/clientservice/sustainability/pathways_low_carbon_economy.asp The interesting thing is that the first chunk of carbon abatement actions actually *pay for themselves*: they are worth investing in independent of any government incentives or support.
105050. KeenOn350 at 07:09 AM on 9 November 2010
        Solving Global Warming - Not Easy, But Not Too Hard
        [A little PS: Maybe a sister site for solutions would be a good thing - this is going to be a big topic!]

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