Well, it’s not really all about me. But methane has figured strongly in a couple of stories recently and gets an apparently-larger-than-before shout-out in Al Gore’s new book as well. Since a part of the recent discussion is based on a paper I co-authored in Science, it is probably incumbent on me to provide a little context.
First off, these latest results are being strongly misrepresented in certain quarters. It should be obvious, but still bears emphasizing, that redistributing the historic forcings between various short-lived species and CH4 is mainly an accounting exercise and doesn’t impact the absolute effect attributed to CO2 (except for a tiny impact of fossil-derived CH4 on the fossil-derived CO2). The headlines that stated that our work shows a bigger role for CH4 should have made it clear that this is at the expense of other short-lived species, not CO2. Indeed, the attribution of historical forcings to CO2 that we made back in 2006 is basically the same as it is now.
As is well known, methane (CH4) is the greenhouse gas whose anthropogenic increase comes second only to CO2 in its 20th Century effect on climate. It is often stated that methane is ‘roughly 20 times more powerful’ as a greenhouse gas than CO2 and this can refer to one of two (very different) metrics. If you calculate the instantaneous forcing for an equivalent amount of CO2 and CH4 (i.e. for a 1 ppmv increase in both), you find that the global forcing for CH4 is about 23-24 times as large (depending slightly on the background assumed). Separately, if you look up the Global Warming Potential (GWP) of CH4 in IPCC AR4 (the integrated forcing of a kg of CH4 compared to kg of CO2 over a 100 year period), you get a value of about 25. GWP is used to compare the effects of emissions today on climate in the future. The numbers are only coincidentally similar since the GWP incorporates both the weight ratio and the ratio of effective lifetimes in the atmosphere which roughly cancel for a 100 year time-horizon.
In the Second Assessment report (1995), the GWP for methane was 21, and it was increased in AR4 because of a greater appreciation for the indirect effects of methane on atmospheric chemistry, and in particular its role as a tropospheric ozone precursor (since increasing methane leads to an increase in low level ozone). There is also an indirect effect on stratospheric water vapour where methane oxidation is a significant source of water in an otherwise very dry region. Both tropospheric ozone and stratospheric water vapour are effective greenhouse gases so including these indirect effects made the net effect of methane greater.
In the standard ‘forcings bar chart’ such as seen in Hansen’s papers, or in TAR, or AR4 (figure 2.20), each change in atmospheric composition is given a separate column. Thus ozone and aerosol effects are denoted separately. Starting off with a paper we wrote in 2005, though, a different approach that is perhaps more useful to policy makers has also been adopted. This ’emissions-based’ viewpoint attributes the forcings to the actual emissions, rather than to the eventual concentration. Thus since some of the ozone increase is related to CH4 emissions, you get to include that under CH4. The other ozone precursors (carbon monoxide and volatile organic compounds) can also now be blamed for a portion of the ozone impact.
This was incorporated into figure 2.21 in AR4, where it is clear that the impact of methane (once some indirect effects are included) is greater than you would have thought based on the ‘abundance’ viewpoint. Note the changes basically only affect the reactive species. When thinking about the various metrics, the emissions-based view is more closely tied to GWP than the traditional abundance-based approach. A big difference is that GWP is looking forward in time, while emission-based forcings are looking back at historical events.
The increasing sophistication when it comes to attribution and GWP is strongly connected to the development of more comprehensive Earth System Models (ESM) in recent years. These are the descendants of the General Circulation Models of the climate that have been developed over the last 30 years, but that now include interactive atmospheric chemistry, aerosols (natural and anthropogenic) and sometimes full carbon cycles in the ocean and land surface. This extra machinery allows for new kinds of experiments to be done. Traditionally, in a GCM, one would impose atmospheric composition forcings by changing the concentrations of the species in the atmosphere e.g. the CO2 level could be increased, you could add more sulphate, or adjust the ozone in the stratosphere etc. However, with an ESM you can directly input the emissions (of all of the relevant precursors) and then see what ozone levels or aerosol concentrations you end up with. This allows you to ask more policy-relevant questions regarding the net effects of a particular sector’s emissions or the impact of a specific policy on climate forcing and air pollution (see here for a discussion).
Our new Science paper (Shindell et al, 2009) expands on some of the earlier work (as was discussed here) and extended consideration of the indirect effects of CH4 and CO (carbon monoxide) to aerosols as well. This is necessary since SO2 requires oxidants to transform to sulphates (and so is affected by the perturbation of the chemistry by other emissions), and it takes into account the competition between nitrates and sulphates for ammonia (which means that there is a small anti-phasing effect – increasing sulphates tends to decrease nitrates and vice versa). When we did this, we found that methane’s impacts increased even further since increasing methane lowers OH and so slows the formation of sulphate aerosol and, since sulphates are cooling, having less of them is an additional warming effect. This leads to an increase in the historical attribution to methane (by a small amount), but actually makes a much bigger difference to the GWP of methane (which increases to about 33 – though with large error bars).
Currently methane levels are relatively stable (despite small upticks in the last two years) and are running below IPCC projections made in 2001 (this of course is good news). However, CH4 is at more than twice its pre-industrial concentration and so still presents a tempting target for emission reductions which, because of our new work and the relatively short lifetime in the atmosphere, will likely be a little more effective at reducing future forcings than previously thought. Given the value of methane as a fuel, it is likely that more of it will be captured (as in this recent story).
CO2, however, is still increasing dramatically despite the slow down in the economy, and so current growth in radiative forcings is dominated by CO2 and that will very likely continue for decades. Despite our increasing appreciation of the role of other forcings (including land use for instance), the overwhelming driver of climate change in the 21st Century will be CO2 increases.
In a follow-up post, I’ll discuss the sources of methane and the implications of the new results for attribution of climate forcing to different sectors (including agriculture), where there have been some very odd (i.e. wrong) recently published numbers.
Andy, here’s the summary. Two amendments; one has a vote on record, the other was passed without taking the names (voice vote):
Reporting of Greenhouse Gas Emissions for Greenhouse Gas Registry: This amendment added language to the bill prohibiting EPA from requiring livestock feedlots to report on their methane emissions as part of the reporting of greenhouse gas emissions for the Greenhouse Gas Registry. (This Latham (R-IA) amendment was adopted by a vote of 31-27.)
Biological Sources of Greenhouse Gas Emissions: This amendment added language to the bill prohibiting EPA from promulgating a regulation to require Clean Air Act permits for emissions from biological processes associated with livestock production. (This Tiahrt (R-KS) amendment was adopted by a voice vote.)
Comments and responses are interesting, for those who like this kind of thing:
http://epa.gov/climatechange/emissions/downloads09/documents/SubpartJJ-ManureManagementRTC.pdf
My understanding of agriculture emissions of methane, and thereby CO2 in 10-12 years, is as follows–
Some time ago there was a report that termites were a major source of methane. Their gut bacteria convert cellulose to sugars with methane as a byproduct. So to protect the climate some method for preventing termite farts should be developed.
The deal is that the termites eat cellulose that was made by trees, or whatever, but this was created by plants that extracted CO2 from the atmosphere. So the methane release just replaced CO2 that had been extracted. A zero sum game.
This is also true of cows, pigs, chickens, or whatever, but only as long as they ate vegetable products that grew naturally. That would be vegetable matter that cultivated or not, did not require any fossil carbon for its growth. The methane produced by a cow (or whatever critter) raised on corn that required fossil fuels for machinery, pesticides, and fertilizer for its production adds to the world CO2 load by the amount of these fuels required. This fossil carbon, and that for any other agricultural products produced for sale, is what the agriculture industry should be taxed for because it adds to the global CO2 load.
Agricultural products can be produced without fossil fuels, but at a higher monetary cost to us consumers. This extra cost represents the, up till now, ignored “externality” of green revolution agriculture fossil carbon. If we all wish to contribute to preventing a major negative ecological, and resulting negative societal, shift we will have to pay more for our food. It is interesting that the poorest people of our world would not be affected at all by this change in production.
Anybody, please explain where I am going wrong with this reasoning from an economic or physics point of view. Steve
Steve Fish (#53),
It is not entierly true that only fossil fuels add to atmospheric CO2. If forests are cut down for the sake of agriculture or animal husbandry for instance, carbon that was tied down will be released into the atmosphere.
In my mind there is a more serious misconception in what you wrote though: some of the poorest people would of course be very much be affected by an increase in the price of food in general and cereals in particular, which are globally traded commodities purchased by most of the world’s poor. This was vividly demonstrated in 2007-2008 and humanitarian organisations such as Oxfam had reports about the situation. Price is not a good way to think about such issues anyway. What matters is whether the amounts produced are adequate and I don’t understand how grain production could be sustained at anything like the currents levels without fossil fuels.
Only a small fraction of fossil fuels are used in agriculture and that that is one of the most humanitarian uses for these fuels. There’s plenty of pointless, gross waste by the richest people of our world that could be addressed before cutting food production. But of course the rich wouldn’t be rich if they could be made to take on burdens instead of the poor.
If you’re looking for measures that wouldn’t affect the poorest amongst us too much, curbs on grain-fed livestock and meat consumption in general would do the trick.
“Anybody, please explain where I am going wrong with this reasoning from an economic or physics point of view.”
Your instincts are good: there is an important difference between fossil-derived methane and bio-methane, which is that when they oxidize to CO2 in the first case it adds to CO2 concentrations, and in the 2nd case it is CO2-neutral.
What you’ve missed is that during the time that the methane was still methane, it has a radiative forcing that is 70 times that of CO2 per kilogram – and in addition, there are side effects from methane of increased ozone production, reduction in hydroxyl radical, etc. Having said that, we mostly don’t care about termite methane anyway – the general presumption is that natural sources that existed preindustrially get a pass (and would be very hard to control). On the other hand, massive rice paddies, giant herds of cattle, etc. are all larger in extent and number and methane emissions than the natural wetlands and bison herds and so on that they replaced. So between our voracious appetites for food on industrial scale, and fugitive methane emissions from landfills, coal mining, natural gas operations, etc., we have added enough methane emissions that methane concentrations are more than double their preindustrial levels (a little less than 1800 ppb today, about 715 ppb preindustrial).
Thanks, Marcus! Appreciated.
For a long time I have been wanting to ask about WF Ruddimans ideas in his book ”Plows, plagues and petroleum”. He brings out the idea that humankind has been affecting the methane cycle for a very long time (millennia).
How broadly accepted is his idea?
Should I count it as a wild idea, a good thought , a probable explanation or..??
Anonymous Coward (~#54. 14 November 2009 @ 7:51 AM), and
Marcus (~#55, 14 November 2009 @ 8:44 AM):
I agree with you both, except for some minor quibbles.
Anonymous Coward (why not just use your name, I feel silly typing this), it is true that there is a pulse of carbon released by cutting a forest for agriculture, and for building your home for that matter (mine is made of recycled steel), but to accurately access the ultimate size of the pulse, you also have to subtract from this any carbon taken up by whatever is planted in its place. If sustainable agriculture were used, this could remove more carbon than the pulse, over time, by improving the soil. I am not sure if there is a difference in methane release from a mature forest and that from agriculture on the same land, perhaps Gavin will deal with this in the future.
I should have qualified that the poor I was speaking to were those folks still engaged in subsistence agriculture. Unfortunately this group is shrinking because of the unsustainable, but inexpensive fossil fuel derived food that mega-agriculture is selling to them. They are also being entrapped into unsustainable (for them) agriculture by GMO crops. Such farmers, and farms, all over the world will have to be rehabilitated. I agree about the waste.
I have two questions for you– What is the percentage of atmospheric carbon derived from fossil fuels used in agriculture? What is your plan for all the poor people when fossil fuels become so expensive that they won’t be able to afford the food (this may not be far off)?
Marcus, I am aware of how methane works in the atmosphere. In the idealistic sustainable agriculture world, the amount of methane (from agriculture) would not be adding fossil carbon to the atmosphere and would be constant. We agree. We just have to deal with this. One way is to aggressively capture and use methane in order to minimize the atmospheric phase of this carbon. I would be interested in any ideas you have beyond removing a large percentage of humans from the earth.
Steve
Andy, Hank, et al: If they were to report emissions, how do feedlots and other livestock farming operations measure and then report their actual methane and CO2 emissions?
PS, never mind my question. Hank’s reference provided info sufficient for my interests.
Thanks, Gavin.
Before reading your post, I had the most recent Science smack dab in the middle of my desk, open to Shindell et al 2009. I thought it was an interesting read, but this is the first time for me that I’ve read an article *before* the spin came out.
It’s a strange experience. I never would have imagined how the head-in-the-sand club could have twisted this the way they did. It shows how clever they are, which is the really alarming thing: the deniers aren’t stupid; they’re actually rather smart, and that’s why they’re so dangerous. They’re of that class of intelligent people who, rather than using their brains to discern the truth, instead use them to promote their own agenda/predetermined conclusions.
Peter
MS, put “Ruddiman” in the (Site) Search box (top of the page)– much here.
MS (57) — Being but an amateur here, I’m not in a position to say how generally accepted Ruddiman’s ideas are. He has his critics and ably answers (most of) their objections; see his highly readable papers on his web site.
His thesis includes not only methane (early rice production, for example) but also carbon dioxide levels. With regard to the latter, the increases during times of extensive land clearing for agriculture and decreases following great plagues is quite stricking. One such example is the decrease in CO2 concentrations following the spread of smallpox throughout the Americas; very good correlation with the regrowth of forests on both continents.
IMO Ruddiman overstates the case for how cold it would be in, say, England without the human contribution to global warming (so-called greenhouse) gases. Certainly cooler with lower CO2 and CH4 levels, but not as cold as all that! Orbital forcing predictions show quite well that the next attempt at a stade (massive ice sheets) would not be due (baring anthropognic influences) for another 20,000-30,000 years.
On the other hand, Ruddiman in a recent paper with a co-worker answers the objection of those wondering how so few people could have such a large influence on climate. The answer is simply less efficient agriculture than is now practiced; each farmer had a much larger impact then.
All told, I think Ruddiman’s thesis holds up rather well. I regualrly recommend it as a popular beginner’s book about climate. Others do as well. One person stated he lent his copy to a lawyer; upon returning it the lawyer stated words to the effect of “At last! A book about climate I can understand.”
I add that there are several more recent books about climate which might be better starters for those wishing to obtain some overview of climate. Nonetheless, the time prespective of by Ruddiman’s book is, I opine, uniquely important and so should continue to be recommended, right off the bat, to the curious.
A bit OT, but Andy Stahl, thanks for all your hard work at FSEEE.
Sorry for being off-topic. I just noticed the apparent arctic sea-ice extent, reported by the NSIDC has dipped below the 2007 level.
http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png
They also explain what could have caused the reduction in ice formation:
http://nsidc.org/arcticseaicenews/index.html
Thanks for the awesome site: I’ve learnt so much!
PS It’s a bit political, but you could mention what people could do to raise the issue of climate change with their elected representatives. Especially with COP15 ~22 days away.
What dhogaza said, definitely many thanks to Andy Stahl; I hadn’t looked you up to see who you worked for. These are good folks, great website, with a lot of wonderful pointers for people.
#63 “The answer is simply less efficient agriculture than is now practiced; each farmer had a much larger impact then” David, this simply can’t be right. Look at the massively cleared areas in, say, America and Australia. the irrigation, the massive use of chemicals and fertilisers. Compare it to small scale farming with biodiversity retained in hedges and uncleared areas, organic fertilisers, few if any insecticides.
What is the latest concensus re: what contributed to the extreme temps and loss of the arctic ice cover and a substantial loss of the antarctic sea and pack ice in the PETM 50M.y ago. If the level of CO2 in the atmosphere was only elevated by a third over normal levels..what caused the rest of the tipping points to be breached?. Are similar conditions present today?. Did an increasing CO2 suddenly force the uncontrolled interaction with other GH gasses?. Even though this process took roughly 10Ky to take effect. Nowadays the level of CO2 and CH4 is higher than what initiated the PETM, are crucial tipping points already being breached? Could it be that the increase in CO2 caused a sudden explosion of vegetation esp. in the tundra areas and as this vegetation died and began to rot down released massive amounts of CH4 to push a uncontrolled +ve feedback condition? Added to that how much CH4 hydrates were then 50M.y ago stored under the arctic tundra waiting to be released? Comments on this would be appreciated..thanks!
Slightly OT, but why does the IPCC radiative climate forcings bar-chart include stratospheric water vapor but not tropospheric ?
I remember the reason was something about water vapor’s short residence time in the atmosphere, I think, but never understood why that should exclude it from the list.
[Response: It only refers to the component of water vapour change that is caused by human emissions. Nothing we do in the troposphere makes any difference given the large amount of water there already and the very short residence time (10 days or so). However, the stratosphere is very dry and has residence times measured in years. So the oxidation of CH4 (to produce CO2 and H2O) is a big deal (providing about half the water in the middle stratosphere for instance). Therefore an anthropogenic increase in CH4 leads to a direct increase in stratospheric H2O and that is what is counted. Changes in water vapour that occur as a result of temperature or circulation changes are still considered feedbacks. – gavin]
Lawrence, did you read this yet?
https://www.realclimate.org/index.php/archives/2009/08/petm-weirdness/
You asked about a study in an earlier topic but I never found a cite, can you point to that one? https://www.realclimate.org/index.php/archives/2007/12/the-forecast-in-the-streets/comment-page-3/#comment-78385
Oh, for Lawrence Coleman again, speaking of asking for cites,
just above, you write: “Nowadays the level of CO2 and CH4 is higher than what initiated the PETM” — I’m curious where you got that idea. It does bear double checking against the information in the recent RC thread on the PETM.
Steve Fish @ 58
I fear that industrial agriculture is unsustainable for more reasons than just fossil fuel inputs. It is also really tough on soil fertility, which is why fertilizer is such a large a part of it. We are mining phosphate deposits at a similar rate (wrt the amount available) as fossil fuels, and in my opinion they are more fundamental, as nonfossil fueled energy could be used to fix Nitrogen and drive tractors etc. Also we have been mining ground water at an even greater rate, and it is starting to run out in many places. Recent GRACE results estimated anual withdrawls of 54KM**3 for Northern India. These largely one shot agricultural inputs will soon collapse. The crunch may not be far off.
Incidentally there was a Steve Fish in my New Jersey high school class of 70. Any chance that you are the same fellow?
re: #69
Gavin, I think you may be mistaken, the chart is of radiative forcings since 1750, man-made and natural.
Its caption in chapter 2 of the AR4 WG1 report is:
“Summary of the principal components of the radiative forcing of climate change. All these radiative forcings result from one or more factors that affect climate and are associated with human activities or natural processes as discussed in the text. The values represent the forcings in 2005 relative to the start of the industrial era (about 1750). [..]”
Water vapor content hasn’t remained constant since 1750, and its net change is unlikely to have been zero, so it will have provided a radiative forcing.
[Response: A forcing in this context is only for changes in composition externally imposed. Changes in water vapour that happen because of temperature changes affecting the saturation humidity are part of the response, not the forcing. Water vapour does have a radiative impact (which is why there is a feedback), but it isn’t directly affected by emissions. – gavin]
Thanks Hank for the follow up..i’ll look into that, and the website as well.
HI,
Here in Sweden we have on a national weather site, a carbon counter, which works for most of the time, and shows second by second the CO2 figures. It is not a true record but more of theoretical figures. Do you know if there is any such website where this is also done, somewhere in the world.
George
Coward asks: “…what would be the point of focusing on relatively easy methane emissions reductions at this stage?”
Buying time so that we have time to tackle the really big problems. Every hybrid, every CF bulb, every light switch turned off or mile not driven makes a difference and buys time.
#75 George
Try CO2 Now http://co2now.org/
Thanks, Ike Solem, #22. I still await Gavin’s comment on Walter’s work.
Gavin, you are right about the difficulty in measuring deforestation caused emissions, especially since the data is so politically explosive. I wrote an article in Forest Voice about North American deforestation, and its effect on our carbon budget. I proved that by switching from wood to steel framing, our emissions would be lowered more than if we required all new cars to be zero emission vehicles. Top forest carbon scientists helped with the research. The article and background research links are
tinyurl.com/ycxfsqu
tinyurl.com/yc8ncuq
Thomas (~#72, 14 November 2009 @ 11:59 PM):
This is all very scary and pushed to the background, along with ocean acidification, by all the denialasphere hoopla. The crunch may be very ugly.
My part of the Fish clan left Leicestershire for Rhode Island in 1643, moved west in several jumps, and arrived in California in 1925.
mike roddy (~#78, 15 November 2009 @ 9:56 AM):
Thanks for this information. A local, self advertised as green, architect told me that I was being unecological for building an all steel home. I knew he was wrong, but haven’t seen all the information put together like this.
By the way, I couldn’t get your name link to work.
Steve
Many of you probably know about this site; I just found out about it thanks to folks at nnrg.org:
http://www.engaginglandowners.org/
“This resource has been developed by the Sustaining Family Forests Initiative (SFFI) using data from the National Woodland Owner Survey. SFFI is a collaborative of federal and state forestry and conservation agencies, businesses, and nonprofit organizations that realize private landowners play a crucial role in sustaining and nurturing our natural resources. It is coordinated by the Yale School of Forestry and Environmental Studies and the U.S. Forest Service’s Family Forest Research Center. “
Terran, you may be interested in this post on radiative forcing and feedback. Hopefully this will clear things up with water vapor
http://chriscolose.wordpress.com/2009/10/08/re-visiting-cff/
how would the all steel building stack up compared to the plantation timber
house , in my own house i went for steel cladding on a plantation timber frame
steel on steel tends to get a bit noisy
Probably a silly question, but would manure from the 95 million cattle in the United States produce less methane if it the animals were widely dispersed in pastures instead of being concentrated in feedlots?
[Response: Most of the methane from livestock is from their stomach’s fermentation processes, so that isn’t affected. But where you get a lot of effulent all concentrated together in anaerobic conditions, you will get more methane production there. I’m going to guess that this happens more on feedlots than on pasture. I don’t know how big of an effect that is. -gavin]
#73: Thank you for the correction, Gavin.
If I could ask another question about the radiative forcings charts : on page 32 of the Technical Summary (AR4 WG1), there’s a chart ‘Global Mean Radiative Forcings’. Adding up the RF values for the anthropogenic forcings gives 1.72 W/m2, yet the ‘total net anthropogenic’ figure provided in the chart is 1.6 W/m2. The difference between the two is 0.12 W/m2, which happens to be the solar irradiance forcing, the only non-anthropogenic forcing on the chart. How do these numbers fit together? Am I being dim again?
[Response: I don’t think so. The confusion might be because of the way that the estimates are added together. They don’t just take the best guess and do the summation, but rather use the (sometimes skewed) uncertainties for each term and aggregate them into a pdf. I haven’t done the math myself, but I’ll guess that the ‘best guess’ for the total is slightly less than the sum of the best guesses because the uncertainties in aerosols are significantly skewed towards more negative values. It doesn’t look to have anything to do with the solar term. – gavin]
#81 Cheers Chris, reading it now.
Steve Fish,
14 November 2009 at 12:09 PM
Your question: “What is your plan for all the poor people when fossil fuels become so expensive that they won’t be able to afford the food (this may not be far off)?”
Although it was directed at someone else, allow me to answer it:
Ditch fossil fuels as soon as possible in favor of renewables|nuclear (pick your favourite flavour), so the lower demand them will drive the prices lower (or reduce the price increase)
Alternatives exist.
http://www.google.com/search?q=joel+salatin+cow+methane
“Every bit of the alleged science linking methane and cows to global warming is based on annual cropping, feedlots and herbivore abuse. It all crumbles if the production model becomes like our mob-stocking-herbivorous-solar-conversion-lignified-carbon-sequestration fertilization. America has traded 73 million bison requiring no petroleum, machinery or fertilizer for 45 million beef cattle, and we think we’re efficient. At Polyface, we practice biomimicry and have returned to those lush, high organic matter production models of the native herbivores. If every cow producer in the country would use this model, in less than 10 years we would sequester all the carbon that’s been emitted since the beginning of the industrial age.”
— Joel Salatin, Polyface farm
Anne van der Bom (~#86, 15 November 2009 @ 6:29 PM):
My question was regarding the inexpensive food (e.g. corn) that big US agriculture (as one example) is selling all over the world. So, encouraging them to continue their practices with low oil prices, where transportation is a large component of their already high CO2 production, is probably a very bad idea.
As I hinted at in my #58 comment, helping farmers that produce for a local market to learn (or relearn) sustainable agriculture might be a better alternative. This type of agriculture tends to be more labor intensive, and this works well on lo-tech farms in undeveloped areas.
There are are universities that have programs that research “organic” agriculture methods for perfecting the required techniques. In my opinion, we need to spread knowledge not CO2, and thereby improve the agriculture economy in poor nations.
Steve
Gavin, the old cow puncher in me is ponderin’ on it. I think there is a difference in terms of burping methane while munching away out on a grassy pasture, and I suspect that difference is also, in a lesser way, manifested in the cowpies.
I’m guessing that which enters and does not end up hangin’ on their growing bones (less operational use), exits.
They fatten slower on grass, and out it goes – not only more burps and more pies, but possibly richer burps and richer pies.
Steve Fish, #79, glad you liked my article. Architects often claim to be green, but most don’t do their homework, and they’re inundated with timber industry BS at trade shows and even in school.
What did you mean by being unable to find my name link? My email is greenframe@aol.com.
And I’m still surprised that we haven’t heard about Walter. Maybe that means that her work hasn’t been quite accepted by Gavin and others. I’m of course not qualified to make a call on that one, but welcome information on the subject. Margot Roosevelt wrote a very good summary of Walter’s work in the LA Times (searchable on Google).
Re Marcus @ #20, thanks for the detailed info, it is most appreciated.
As to the reason I’m interested in the short term impact of methane, may I refer you to James Hansen and Makiko Sato’s 2004 paper entitled ‘Greenhouse Gas Growth Rates’:
http://pubs.giss.nasa.gov/abstracts/2004/Hansen_Sato.html
A reduction in methane (or NOx, or other trace gases) would seem to produce a fairly significant short term effect and would buy us some time to scale up the new technologies that are required to reduce emissions of fossil CO2. And I’m quite happy to follow their lead on this, they’re climate scientists and I’m not!
I wonder if by averaging the effect of methane over a century, we’re perhaps underestimating the effect that a reduction in methane would have in the short term to buy us the time we seem to need to wean ourselves off coal. I’m not saying that this is a justification of laziness, simply that building many megawatts of new power stations will take time.
As an example, Australia’s CO2 emissions in 2007 were 448.876Mt, CH4 emissions were 5.603Mt. If you use 72 to calculate the near term (20 year) warming impact as CO2-e, that 5.603Mt becomes 403.416Mt (if you use 88 it is 493.064Mt CO2-e).
Re Marcus @ #21, I didn’t get the satire, colour me embarrassed! I have apologised to Inferno on his (?) blog. I did skim over the blog the other day, having read several ‘denialist’ blogs, this one seemed pretty similar, in fact one of the posts was very similar to an argument being mounted by a family member recently (that was a fun family dinner). I didn’t read it too closely, I was starting to get too depressed after hanging out at a certain Herald Sun columnist’s blog to subject myself to more of the same. So I missed the crucially placed ‘imaginative’ in the about section. Oops.
Though I’m obviously not the only one to make this mistake, and I hate to say this but I think that quite a few of the people that I know who would fall for a satirical blog that takes the opposite position. There are gullible people everywhere (of which I am one it would seem, much to my chagrin).
Which is why we should really leave this to the experts, like Gavin Schmidt, James Hansen etc, etc.
#89 Possibly the result of a different rumen flora on grass as there is on , say, pelleted food. Also different digestibility.
There is a lot of organic material in cowpies. Under feedlot conditions, much of that goes to methane. On pasture, that organic material is more aerobic and dryer. On the high plains, it can be incorprated into the soil and persist for centuries. On pasture, over all, a lot less methane is generated.
As you do life cycle carbon footprints, remember the energy to related to the fertilizers and pesticides to grow grain. That also brings the synthetic nitrogen cycle into the analysis.
#89 and # 92
Apparently grass fed cows produce something like 4 times as much methane as high intensity feedlot cattle. And that doesn’t include anaerobic decomposition of the cow pats.
http://jas.fass.org/cgi/content/abstract/77/6/1392
#89 as for ‘cowpies’. I went to a bad taste party once. Everybody had to bring some food. One guy was fooling around and ‘in bad taste’ grabbed a full sized cake and bit into it. Only then did we realize that he had picked the only iced cow pat on the table.
Cheers
76
Ray Ladbury says:
15 November 2009 at 6:36 AM
“Every hybrid, every CF bulb, every light switch turned off or mile not driven makes a difference and buys time.”
No it doesn’t Ray. Not even close. Those things are about assuaging guilt and not about ameliorating co2 emissions. They make absolutely NO difference to emission levels even if every light globe on the planet was changed.
You do the math Ray. How many squiggly light globes would it take to save only 1GT of emission? Hybrids are a joke (They still have to be re-charged on mains electricity.
WAKE UP!! It does not make a difference.
Oh, balls, Steckis. If it reduces electricity consumption, it’s clearly going to reduce emissions, too–unless somehow there’s a demand “feedback” of some sort. Do you have any evidence of any such effect?
A 30-second search turns up this link: http://tinyurl.com/yll23hb
6.5% for lighting; reduce that by 50%, slice 3.25% off total demand.
It’s a simplistic analysis, sure, but show why it’s incorrect if you want to convince.
> Hybrids are a joke (They still have to be re-charged on mains electricity.
No, that’s electric cars. Hybrids use gasoline (or diesel), only do so better (smarter) than regular cars.
Steckis, every watt of electricity not used saves 3 watts of energy. Increased efficiency matters. It ought to be one thing everyone in the debate on remediation could agree on. Increased efficiency is good for the climate AND for the economy. Hell, Dude, if the US automobile fleet had an average fuel efficiency of ~30 MPG, the country would be self sufficient in energy. I would suggest, Sir, that perhaps it is you who should do the math, [edit – don’t start]
Yes really Richard. To make a difference we have to get the emissions trajectory to be decreasing a few percent every year. Those quilt assuaging modifications will give us two or three years worth of that change at almost no pain.
And hybrids (currently not plug ins), do save, they are simply more efficient. Same for plugins or electrics, they need considerably less energy to move around, so much so that they could be powered by coal generated electricity and stil cut emissions. Ever heard of engine breaking (leave your car in gear -or even downshift going downhill to control your speed without braking), the internal combustion vehicle is fighting those considerable loses whenevr the engine is on, the hybrid/electric could be banking the downhill potential energy in the battery.
Now I’ll give you, that those are only a good start, they won’t take us where we need to go long term. But as they say, a journey of a thousand miles begins with a single step. If we are afraid to take that first step, we’ll never get there.
#96 I agree that lighting changes could reduce consumption significantly.
However I wonder about the idea that such reductions ‘buy time’. Buy time for what? Surely it depends upon how the world in general reacts.
Will the world debate the problem in an intelligent responsible manner, come to some reasonable conclusion based upon evidence about what needs to be done and then gets it done.
Or will the world continue on as usual until some event causes such havoc and disaster, that just about everyone remaining takes notice, demands action and is willing to make drastic changes.
Buying time makes sense in the former case, giving extra time to implement change and allowing rather slower change to achieve the required goals.
I am not sure that it helps in the latter, and it is possible it could make the situation worse in the long run. If one has already implemented large numbers of mitigation steps, especially those that could actively remove CO2 from the atmosphere such as reafforestation, while most of the world continues with business as usual then the cupboard will be bare (so to speak) when such efforts are really needed.
Given past performance I know which alternative is most likely, and it isn’t the first.