Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Term:

Settings

Beginner Intermediate Advanced No Definitions Definition Life:

All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Suggested supplementary reading...

From Carbon Brief's daily broadcast email of Apr 11, 2016:

Explainer: 10 ways 'negative emissions' could slow climate change

Starting today (04/11/16), Carbon Brief is running a week-long series of articles looking at "negative emissions" technologies (NETs). With the Paris Agreement calling on the world to keep global surface temperatures "well below 2C", compared to the pre-industrial era, most of the climate modelling to date shows that we will have to, in part, rely on NETs in the second half of the century to "suck" CO2 out of the atmosphere. The problem is there are a range of NETs to choose from - yet none have been demonstrated to work at a commercial scale. In this first article in the series, we explain the 10 technologies most often put forward as a way to remove CO2 from the atmosphere. Tomorrow, we ask a wide range of scientists and policy experts for their views. Carbon Brief Staff, Carbon Brief

One Planet Only Forever at 00:48 AM on 12 April 2016

The 35 countries cutting the link between economic growth and emissions

TonyW,

I agree that the measure of CO2 emissions and GDP are just measures and the 'uncertainty ranges' of those measurements need to be evaluated and be part of the reporting.

Actually, a measure that would be more meaningful would be the true measure of the amount of truly known to be sustainable activity in an economy. There are many other damaging unsustainable activities that cannot be part of a lasting better future for all of humanity. Replacing activity that increased CO2 with other unsustainable or damaging activity is not 'advancement', no matter how impressive the newer consumer toys for the more fortunate appear to be.

Many things that only a portion of humanity can get a reward from, other than CO2 emissions, are creating problems for furture generations (and others in the current generation). It is simply unacceptable that 'leaders' can still claim that their evaluation shows it is OK to make bigger problems for a furture generation because to not make those bigger problems that others will face would cost 'their portion of current day humanity' more than the impacts on future generations (as they figure it).

Putting that into business terms, a claim that the cost to future generations is justified is like a business developing profitability by doing something that actually damages the profitability of other businesses, but because it controls the rule making it gets to declare that they will only limit the damage they do to the other businesses to the amount of profit they believe they would have to give up to stop damaging the profitability of the other companies, then cooking the books to always show that their potential lost profit is always more than the damage they cause (as they figure it).

There is simply no justification for knowingly continuing to create larger problems that others will have to deal with. Clearly a focus on profitibaility and popularity as justification for things can create impressions of acceptability. The ability of 'people who are not very interested in advancing humanity to a lasting better future for all (because many current day people are more easily impressed by the present they hope to get for themselves)' to create and maintain misleading impressions is a fatal flaw of the system, maybe even the greatest weapon of mass destruction humans have ever created.

CBDunkerson at 00:47 AM on 12 April 2016

The 35 countries cutting the link between economic growth and emissions

TonyW, Monbiot has consistently argued that we need to become less materialistic / use less resources to fight global warming (and other environmental problems). He has dismissed the possibility that efficiency, miniaturization, and technology change (e.g. solar and wind replacing fossil fuels) can achieve significant results alone - despite mounting evidence to the contrary. IMO this represents a pre-existing bias in his thinking. Indeed, he even admits as much in one article. Also note, that the 'offshoring' argument (that countries has just shifted their manufacturing and thus emissions to other countries) is specifically addressed in the article above and shown to be not the case for a majority of the countries with declining emissions and increasing GDP.

José M. Sousa at 00:36 AM on 12 April 2016

The 35 countries cutting the link between economic growth and emissions

https://rwer.wordpress.com/2016/04/01/how-to-decarbonize-look-to-sweden/ This article seems also too optimistic. As might be seen in Jessie Henshaw´s comment here: https://rwer.wordpress.com/2016/03/31/co2-emissions-per-capita-united-states-denmark-finland-norway-iceland-and-sweden/

esjope at 21:59 PM on 11 April 2016

The 35 countries cutting the link between economic growth and emissions

These stats don’t include emissions from bioenergy (as it is often calculated as having 0 – emissions, which it isn’t). Also methane emissions are missing. Shipping and aviation I believe are also on the rise still. Emissions from agriculture are not here either. I’m afraid decoupling is much more difficult than these reports let us think.

Digby Scorgie at 19:53 PM on 11 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

I've thought of a problem. Some oil is needed to manufacture plastics. If there is an accelerating increase in the cost of fossil fuel, what is the effect on plastic products? Also, can plastics be manufactured without having to burn fossil fuel?

TonyW at 18:12 PM on 10 April 2016

The 35 countries cutting the link between economic growth and emissions
In a paper last year, as reported on by George Monbiot, it's clear that no decoupling has taken place. Indeed, claiming that an economy has "decoupled", as this post does, implies that there is no link between emissions and an economy, which would require far more evidence than mentioned here.The initial estimates by the IEA cover energy emissions only (and not, e.g. land use changes and cement manufacture). So, even if the estimate is true (and I don't think there is consistent stats on GDP), it doesn't prove that decoupling has happened or is in progress. It is far more likely that emissions are underestimated (which is certainly partly true, as they don't include some emissions) or that economic growth is overestimated.

Trevor_S at 16:09 PM on 10 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

Good interview here with Professor Kevin Anderson about COP21 and the task ahead, he's not very complimemtary but always polite.

Also an interesting lecture he gives at the LSE

Digby Scorgie at 11:27 AM on 10 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

OPOF

Yes, a decreasing per-capita demand for electricity could be due to both increasing efficiency and increasing sustainability.

Right, so the next time some politician says we're reducing our emissions, I can look at my list and say, "These are the things that need to happen. They are not. You are wrong."

One Planet Only Forever at 03:27 AM on 10 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

Digby Scorgie,

I agree with including things like the energy efficiency of buildings in the list.

In keeping with the identification of broader categories "reduced energy consumption" may be the category for the variety of reductions of energy consumption that should be developing. Even the consumption of sustainable energy should be reduced because there are other unsustainable implications related to any type of energy production and distribution, not just the global warming ones (however, burning fossil fuels is clearly the least sustainable way of getting useable energy because unlike the resources required for other methods of energy generation fossil fuels cannot practically be recycled).

And I agree that identifying changes people can personally observe would be a good way to raise awareness of the adaptation/change of their local portion of humanity to the necessary changes required to advance global humanity to a lasting better future for all.

ELIofVA at 00:15 AM on 10 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

Tom Curtis wrote about biochar:

But it can never be a substitute for reducing emissions to zero in the long term.

I totally agree with this statement. I would not suggest that an agressive practice of carbon storage by biochar or any other method would be a substitute for reducing emissions. One of the risk of optimism on geo engineering is for the public to believe we do not need reduce our high emissions lifestyle because a technological fix is coming. ak "Clean Coal Techonology". Therefore, biochar is not a substitue for agressive reductions in anthropogenic emissions. However, when we achieve net zero anthropogenic emissions, (I like to be hopeful) we will still be faced with a carbon concentration that are still too high, causing positive feedbacks such as reduce sea ice (higher light to heat absorption), and release of methane from permafrost thawing. Therefore, warming will continue. We must consider how we are going to sequester and store carbon out of the atmosphere.

I will use the metaphor of a retention pond used to mitigate the threat of flooding in an urban environment. A retention pond has an opening for the discharge or rain water. However, the size of the opening is limited so that during an extreme hard rain, or more frequently when the urban environment has created a very low absorption of run off, the opening reaches a maximum it will discharge and the level of the pond will rise above the level of discharge. Limiting the discharge of water allows the drainage systems below time to remove the water within the their limits and avoid flooding. Eventually, all the water is discharged, but at a rate that can be managed.

So, when we look at carbon capture and storage technologies, we must acknowledge that they may not be absolutely permanent. The planting of trees is promoted as a method of sequestering carbon. Yet a tree has a life cycle in which it will die and decompose the co2 back into the atmosphere. However, like the retention pond, the process has temporarily removed carbon, allowing time to reduce anthropogenic emissions.

Using biochar to more permanantly store the carbon from those trees allows much more time. The Terra Pretta soils of the Amazon demonstrates that the time frame is in the thousands of years. The release of carbon is very slow. Better yet, the environment created is a benifit for micro organisms, micro nutrients, and water retention, improving our potential to produce food in a sustainable way for our hungry population. Therefore there is an ecomomic and local environmental benefit that provides incentive for the process that does not require the achievment of global net zero carbon emissions.

From the book, "The Biochar Solution" page 76 the author quotes the belief by Rattan Sal, a soil scientist from Ohio State University that best practices could reduce atmoshperic carbon by 1ppm/4 years. Currently we are increasing by 2ppm/year. Obviously, the best methods do not compensate for current emission practices. Best practices includes other methods beside biochar such as no till farming. Sorry that I do not have a link to that information. However, I found this lecture by Rattan Sal that discusses the potential for capturing carbon as a mitigation strategy for climate change.

http://presenter.cfaes.ohio-state.edu/link/Ratan_Lal_5-7-12_-_Flash_%28Large%29_-_20120507_03.37.06PM.html

Mal Adapted at 23:38 PM on 9 April 2016

Dangerous global warming will happen sooner than thought – study

Tom Curtis @64:

Ergo, if the term is orwellian, then it is likely that many, even most would not agree with the implicit values encouraged by the term with clearer thought. And again, just because a term is misleading does not mean that all who use it are misled or intend to mislead.

Tom, I have no doubt we agree on many things. The importance of clear thinking is one of them 8^)!

Digby Scorgie at 18:42 PM on 9 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

Glenn #7

I presume that a decreasing per-capita demand for electricity would imply increasing energy efficiency?

OPOF #8, 9

I think my item on electric vehicles could be modified to cater for your comment about transport. In essence the whole transportation system would have to be seen to be changing to one less reliant on fossil fuel.

Regarding politicians, seeing politicians of all persuasions agreeing on the problem posed by climate change would be an indication of a country's commitment to tackling the problem. But is it an essential characteristic?

Your comment about meat and vegetable protein is probably included in my item on agricultural practices. In fact, delete "agri" and you get "cultural practices", which would indeed have to change if people are to eat less meat!

Finally, you have persuaded me that I should not have been so hesitant about forestry. It should go on the list as a separate item from agriculture.

Additional thoughts

Another belated thought of mine is that the approach to buildings, both commercial and residential, should also be seen to change to designs that require less energy to maintain. There is not much one can do about existing building stock, but at least new buildings can be constructed to a much more environmentally friendly building code.

We would probably end up with a check-list of about ten items against which to measure the performance of countries. I reckon my own (New Zealand) would score one in ten — unless our benighted politicians pull finger!

However, I have to end by saying that I'm aware that many people are going to a lot of trouble to compute each country's emissions. Theoretically these are all that should be necessary to track a country's progress. Unfortunately, from all I've read, these computations seem fraught with error and subject to abuse. I put no trust in them. I'd much sooner trust a list of the kind I've been sketching, one that lists practical and tangible steps that all can see.

One Planet Only Forever at 15:08 PM on 9 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

Digby Scorgie,

A couple of other things to look for:

Reduced global meat consumption, particularly beef.
Increased planting of vegetable protein crops (like beans). This one is already starting to happen in Western Canada.
Reduced rainforest destruction, transitioning to reestablishing rainforest extent.
And yes global expansion of forestry practices that selectively harvest fully mature trees in designated harvest zones while reducing the extent of zones where trees are harvested and locking in the harvest to those zones (unlike the common Western Canadian practice of permitting new areas be harvested rather than requiring the harvesters to manage their future on a set area of land they have to manage the effective regrowth of to have a future).

One Planet Only Forever at 14:47 PM on 9 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

Digby Scorgie,

A few other indications that the message about the required changes is sinking in would be:

Reduced plans to produce overpowered oversized personal use vehicles.
Reduced resale value of overpowered oversized personal use vehicles.
Increased public transit networks with increased renewable energy driving them.
Leaders (in power and in opposition), all declaring openly and frequently that the change needs to happen even if the message is not popular with the "commonly considered to be locked-in reliable voter base of a particular leader's party". And having them all honestly and most fully inform the entire population rather than deceptively try to gain political popularity through misleading messages.

The last point will require the development and implementation of effective laws regarding full and proper presentation of information on an important issue like this (similar to the laws that have recently been developed for commercial marketing - but needing to be more effective than the commercial ones), and effective enforcement of those laws. Of course, many of the current people in positions of influence and leadership related to the making up of the rules can be expected to be reluctant to do this. This change of the game would have far greater impact than helping to more effectively advance humanity out of the damaging fossil fuel burning phase that has been so difficult to break free of (like breaking out of any other damaging addiction the first step is publicly admitting to the problem, then constantly working to overcome the tempting influence of those who would try to tempt the addicted into returning to, prolonging or increasing their addiction).

John Hartz at 11:47 AM on 9 April 2016

Dangerous global warming will happen sooner than thought – study

For those of you who want to brush-up on your understanding of the "tragedy of the commons", here's hand-dandy education module...

Introducing the economic concept of 'tragedy of the commons' using global warming, Laura Triplett, Gustavus Adolphus College

Summary

In this 50-minute classroom activity, students begin by discussing historical environmental problems that demonstrate the economic principle of the 'tragedy of the commons'. The examples available here are sewage disposal in the Mississippi River, smog in London, and the ozone hole, but other examples could be used. Next, the instructor poses the question of whether global warming fits the tragedy of the commons model, and teaches some basic climate literacy concepts. Then, students brainstorm possible economic solutions to the global warming tragedy-of-the-commons. Instructor finishes by giving examples of economic solutions to historical environmental problems. This could easily lead into topics such as monetary and fiscal policy, economic development and globalization.

This class was developed as part of the Interdisciplinary Teaching of Geoscience for a Sustainable Future (InTeGrate) project funded by the NSF in August, 2011.

RedBaron at 10:04 AM on 9 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

Tom,

That is a far more reasonable explanation. I would agree that there is no substitute for carbon zero energy long term. But I don't believe that really is the point of carbon farming either. I see the point being to remove the excess already in the atmosphere, not as an excuse to ignore alternatives to fossil fuels. Without alternative energy sources long term, obviously there will reach a time when there really isn't any way we know of to remove that extra CO2.

On the other hand even with zero emissions tomorrow, AGW lasts for a very long time. We simply have to help with drawdown, and it's a good thing too, because the soils need that carbon. In my opinion the loss of soil carbon caused by poor agricultural management is an even more pressing issue, with even more catestrophic potential than extra carbon in the atmosphere. Since the solution to both includes moving some of that carbon already emitted by fossil fuels to the soil. I see any accounting defenciencies that you mentioned as a failure of accounting systems, not a failure of the principle of carbon farming in it's many forms.

Tom Curtis at 09:24 AM on 9 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

RedBaron @21:

"Any further decomposition of biochar after sequestered in the soil, although very slow, would be carbon sequestered"

Yes (obviously), but when sequestering the full carbon content sequestered is accounted for as coming out of the atmosphere. When figures are quoted for carbon sequestration by biochar, the amount cited is the amount buried at the time of first burial. Not the amount still in the ground after 100, or 1000 years. Therefore any decomposition must be accounted for as new emission to balance the books. And unfortunately it is a new emission that is hard to account for and easy to falsely pass of as a natural emission.

The result is that people who do not explicitly acknowledge the decomposition (or in most cases even know of it) might think that two pathways, one in which emissions are reduced by 400 GtC by replacing fossil fuel with renewables and one in which 400 GtC is buried as Soil Organic Carbon, and the fossil fuel emissions not reduced, are equally valid responses to climate change. But they are not, first because the Soil Organic Carbon burial would need to be ongoing, but also because some of that carbon in the Soil Organic Carbon will make its way back into the atmosphere, and over the long term, most of it will.

That means the role of burial of carbon by improved farming practises represents a good way to buffer the response to global warming. It allows us to slightly overshoot emission targets to remain below 2 C and recover the difference by sequestration through farming practices. But it can never be a substitute for reducing emissions to zero in the long term (or indeed, within the next 50 years). And, what is more, it is a buffer which comes at a cost. For increased SOC by improved farming practises, that cost is the need to maintain those practises in the long term to retain the equilibrium of SOC. If for economic reasons we drop those practises in the future, the extra carbon buried will quite rapidly return to the atmosphere (on the order of a century or two). Biochar, though more limited in the rate at which it can bury carbon, is far more stable so that the rate of return to the atmosphere can take from thousands to tens of thousands of years. For low levels of biochar, the impact of that will be negligible, but for very high levels it is not. That means we would need to either commit to long term burial of biochar at a rate to compensate for the decomposition (or other means of sequestration), or not have as great a reduction in temperature as a result of the natural drawdown of CO2 into the ocean.

Note further that similar problems beset other forms of sequestration. Even for deep burial in geological strata, there will be leaks so that some indeterminate percentage will be returned to the atmosphere over time. Indeed, with that method there is the possibility of catastrophic failure of a reservoir and a rapid short term release of some of the CO2 sequestered. Consequently I think that methods of sequestration by improved farming practise are preferable to the use of biochar, which is much preferable to more industrial means of sequestration. But none of them can be a substitute to converting to an emissions free energy and transport system.

RedBaron at 08:45 AM on 9 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

Tom @ 21,

Any further decomposition of biochar after sequestered in the soil, although very slow, would be carbon sequestered from the atmosphere via photosynthesis in the first place, thus rendering it at worst carbon neutral and in no way "increases the long term stable temperature", but rather contributes to long term stable temperature decreases. Agreed it is not large enough to actually decrease temps on it's own, but in no way does it contribute to increased temps, now or in the future. That carbon came from the atmosphere and at the very worst in some extremely long distant view it could be considered carbon neutral once it eventually in thousands of years decomposed completely. Assuming worst case scenario of no transfer to another long term sink besides the atmosphere. The natural cycle adds and removes CO2 to keep a balance; fossil fuels add extra CO2 without removing any. For this reason natural cycles do not add to AGW, but burning fossil fuels does. Also for this exact same reason, since the biochar is sequestered long term, it reduces atmospheric CO2 long term and helps make up part of that lost balance. So for a third time I will ask for a citation. Otherwise just admit your logic was flawed, you made the same mistake climate deniers often make but in reverse (see denier argument #33 and rebuttal from this website), and we move on.

Tom Curtis at 08:27 AM on 9 April 2016

Dangerous global warming will happen sooner than thought – study

Mal Adapted @63

"That was a little garbled"

Yes it was. Try:

"I utterly reject, however, your implication that because I think a term is misleading that it will mislead all who use it; or that all who use it because it is a commonly recognized term personally intend to insult the sufferers of the historical tragedy of the commons. That is entirely a strawman."

I apologize for my poor copy editing.

"you didn't actually mean that the term "tragedy of the commons" can only be used to "justify the seizure of customary rights of access to land/and or fisherys and giving them a simple property rights to the wealthy", "Nothing more, and nothing less", then we have no dispute."

In my original claim, I intended to indicate that that the rhetorical use of the term to justify the seizure of customary rights was a modern enclosure movement, "nothing more and nothing less". That makes the term "the tragedy of the commons" orwellian, as I claimed. I did not mean to indicate that anybody using it had orwellian intent. Indeed, it is the nature of orwellian words that they shape your thoughts regardless of your actual intentions, thereby leading you to accept or justify things you would not accept or justify if thought about clearly. Ergo, if the term is orwellian, then it is likely that many, even most would not agree with the implicit values encouraged by the term with clearer thought. And again, just because a term is misleading does not mean that all who use it are misled or intend to mislead.

But again, just because not all are misled by a term does not mean a misleading term should not be replaced by a better one.

Mal Adapted at 08:10 AM on 9 April 2016

Dangerous global warming will happen sooner than thought – study

Tom Curtis@62:

I utterly reject, however, your implication that because I think a term is misleading that it will mislead all who use it; all that all who use it because it is commonly recognized personally intend to insult the sufferers of the historical tragedy of the commons. That is entirely a strawman.

That was a little garbled, but if by:

In current usage, the term "tragedy of the commons" is used to justify the seizure of customary rights of access to land/and or fisherys and giving them a simple property rights to the wealthy. It is in fact, a modern enclosure movement. Nothing more, and nothing less.

you didn't actually mean that the term "tragedy of the commons" can only be used to "justify the seizure of customary rights of access to land/and or fisherys and giving them a simple property rights to the wealthy", "Nothing more, and nothing less", then we have no dispute.

Tom Curtis at 07:55 AM on 9 April 2016

Dangerous global warming will happen sooner than thought – study

Mal Adapted @61 your case that my point represents an insult to Elinor Ostrom ignores the fact that she found the term "Tragedy of the Commons" sufficiently distorting of what actually happens on commons that she used instead the term "Drama of the Commons" for the title of the book, which in turn points out a multitude of instances where what happens on the commons is not adequately described by Hardin's term.

My point is that Hardin's use suggests that there is only one possible tragic result from use of the commons - something which is definitely false as shown by the tragic results of enclosure. In doing so it belittles the actual historical tragedy in favour of a hypothetical tragedy whose rhetorical use is to justify replicating the historical tragedy. That it has that rhetorical use does not mean it cannot, and has not been used by others in careful analysis. For that purpose, however, more neutral terms such as "n-person prisoner's dilemma" or the "Gordon/Schaeffer model of the Commons" would be appropriate. (The later term recognises two people who independently and formally analyzed the scenario Hardin later informally analyzed but gave a catchy name to.) In general, rhetorically motivated names do not aid clear analysis. Rather the contrary. But they no not make it impossible.

Indeed, I have already pointed out that one of your examples was such an example of poor analysis. Specifically, the analysis by Berger-tal et al was impoverished by thinking an unusual 'tragedy' in the commons where mutual grazing resulted in both grazers eating less than half of what they would have eaten alone was thereby an example of 'The tragedy of the Commons'. In this case, the claim in Hardin's term that there is one, and only one type of tragedy related to the commons has directly lead the researchers to misclassify the type of situation they discovered.

You are welcome to defend a term that both misleads and is offensive on the grounds of mere custom. I, on the other hand see no reason to do so. I utterly reject, however, your implication that because I think a term is misleading that it will mislead all who use it; all that all who use it because it is commonly recognized personally intend to insult the sufferers of the historical tragedy of the commons. That is entirely a strawman.

Tom Curtis at 07:31 AM on 9 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

sidd @12, thanks for the presumably interesting reference. I say presumably because it is behind a paywall and for some odd reason, Nature won't accept my money to let me get beyond it. I have, however, found an interesting Scientific American article on the Nature article. The key quote is:

"The study says that if all the Earth’s farmers were to manage their fields so the soil stored more carbon, the impacts of the greenhouse gases emitted from burning fossil fuels annually could be cut by between half and 80 percent.
More realistically, the emissions reductions would likely be much lower, possibly between 10 and 20 percent of total annual human emissions.
“The question of what the most ‘realistic’ potential is, is not really possible to answer directly, at
least from a science perspective, because it really depends on enactment of policies that would encourage adoption of the climate-smart soil management practices,” study lead author Keith Paustian, a soil ecologist at Colorado State University, said."

The figures you cite (22.9%) presumably come from the discussion of the "more realistic" figures, which therefore comes with the important qualification that what counts as realistic depends on the policies actually adopted. The Scientific American article does show that the various news releases that only report the 80% figure are overegging the study, indicating the upper limit of a scenario that is not considered realistic.

One question I have is, does the paper discuss the effect of the decomposition of the Soil Organic Carbon overtime, and in particular the total amount sequesterable under equilibrium conditions for the farm management practises dicussed?

Tom Curtis at 07:13 AM on 9 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

RedBaron @19, the citation for that quote is https://www.skepticalscience.com/news.php?n=3340#116774

I am unsure why you need it.

Perhaps you meant a citation for the claim made within the quote. The contentious part of the quote, however follows from two simple syllogisms:

1) Biochar decays to CO2 and other decay products over time;

2) CO2 from biochar decay is emitted to the atmosphere;

3) Therefore, over time, ceterus paribus atmospheric CO2 will increase overtime as the result of biochar.

And

1) CO2 is a greenhouse gas;

2) Increasing greenhouse gases increases the total greenhouse effect;

3) Therefore, ceterus paribus, increasing CO2 will increase Global Mean Surface Temperature Overtime.

Now admitedly I allowed for all not being equal, specifically the natural draw down of CO2 if net anthropogenic emissions are reduced to zero, so that the temperature increase is only relative to what it would have been with the draw down from an equivalent initial peak CO2 level achieved by a more rapid transition of the energy economy, and no use of biochar. That, however, does not change the logic of the case.

No citation is needed for the conclusion of a syllogism, no matter how obdurate is the person with whom you discuss the issue.

So, unless you are claiming that biochar does not decay, simpliciter, (in which case see this, this, this, and and this) your request for a citation is bizarre. If that is what you are requesting a citation for, you should have actually quoted my claim to that effect.

But, I remain convinced that your request of a citation is just the response of somebody who has not coherent response to my points; but has to post something to disguise that fact.

Tom Curtis at 06:25 AM on 9 April 2016

Factcheck: Are climate models ‘wrong’ on rainfall extremes?

martin @2, Professor Sherwood's comment can be found here (along with two others). In full, he states:

"They did a lot of work and its a nice study and a valuable proxy dataset, but it has many complexities in the way it was done. They are heavily smoothing the data so as to look only at centennial-scale shifts, not what we usually think of as droughts or rainfall extremes (which would be scales of days to at most a decade or two).
Previous studies, based on models, have shown that warming-induced trends in regional precipitation have not yet emerged from natural variability (“noise”). This seems inconsistent with the paper’s claim that the changes predicted by these same models are unrealistic, since it should not yet be possible to tell even according to the models themselves.
They normalised all data series to unit variance over the 1200 years. If I understand correctly, that means if there is too little natural variability in the models (which has been reported in other studies) or noise in the proxy observations (which is inevitable), either of these would help create an apparent discrepancy such as they’ve noted. Thus, other interpretations of their results may be more consistent with past studies.
In models, they looked at precipitation, but the observational proxies they have are probably measuring soil moisture or something similar. Many people think these two quantities are equivalent, but they are not, because as soon as you warm the whole planet they decouple (precipitation generally goes up while soil moisture may stay the same or go down). This will cause discrepancies during the last century, due to the global warming not seen in earlier periods. Future studies should compare these hydroclimate proxy results to a more appropriate model variable such as soil moisture.
If this paper’s conclusion about model overprediction holds up to further scrutiny it will be extremely interesting; my own work focuses on model-data discrepancies so I am particularly interested. But due to the above aspects of the study, I am not convinced that this particular conclusion will hold up. We shall see, as I am sure this result will attract lots of attention."

The claim appears to be that Llungqvist et al themselves smooth the data rather than that it is innately smoothed. The reason the observational proxies "are probably measuring soil moisture" is that trees draw their moisture from the soil, not the air, and therefore respond to soil moiture rather than directly to precipitation.

Michael Mann' facebook page (link in main article) refers to several of his own peer reviewed papers to justify his comment regarding extremes:

"Our own extensive work analyzing paleoclimate proxy data has shown that they are not well suited for reconstructing past climate *extremes*. Tree rings and many other chemical and biological climate proxy records, by their nature, tend not to record very large short-term fluctuations, and for this reason they are likely to show muted extremes, i.e. less extreme variation than actually exists in the climate record. We published several articles demonstrating this problem over the past several years:
Schurer, A., Hegerl, G., Mann, M.E., Tett, S.F.B., Separating forced from chaotic climate variability over the past millennium, J. Climate, 26, 6954-6973, 2013.
Mann, M.E., Rutherford, S., Schurer, A., Tett, S.F.B.,Fuentes, J.D., Discrepancies between the modeled and proxy-reconstructed response to volcanic forcing over the past millennium: Implications and possible mechanisms, J. Geophys. Res. 118, 7617-7627, doi:10.1002/jgrd.50609, 2013.
Mann, M.E., Fuentes, J.D., Rutherford, S., Underestimation of Volcanic Cooling in Tree-Ring Based Reconstructions of Hemispheric Temperatures, Nature Geoscience, 5, 202-205, 2012.
(all available here: http://www.meteo.psu.edu/…/publi…/Mann/articles/articles.php)."

That being said, the relevant sections of all three articles are about responses of proxies volcanism, which is not an evident factor for the 20th century period in which the discrepancy lies. On that basis, I cannot see the relevance of Dr Mann's remarks.

martin3818 at 00:08 AM on 9 April 2016

Factcheck: Are climate models ‘wrong’ on rainfall extremes?

I have a few questions.

Why do tree rings smooth the signal for precipitation so strongly?
I would have expected a tree ring not to smooth more than the one year it takes for a tree ring to grow.

How does this paleo reconstruction for the twentieth century compare to direct measurements?

Why do the reconstruction and the models stop agreeing for the twentieth century? Did the number of precipitation extremes increase significantly?

Glenn Tamblyn at 16:23 PM on 8 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

"Are there other effects we will be able to see?"

Substantial improvements in energy efficiency across the board.

bozzza at 16:05 PM on 8 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

Global Accounting methods exist for a reason: to prevent Anarchy in the market place.

Global Warming is a mixed markets failure that is purely down to the worlds Governed markets picking fossil fuels as the winner!

Extraction of said intervention into the fabled free-marketplace was never going to be easy and any year 11 economics high school student could tell you that. There is a lot of vested interests in messing with the numbers here and if the educated taxpayer that supports it all gets wind of a ruse it's anarchy full stop!

If biochar and soil sequestration can't be reliably quantified then they can't be reliably quantified.

Digby Scorgie at 10:44 AM on 8 April 2016

After COP21: 7 Key Tasks to Implement the Paris Agreement

OPOF #5

Yes, that was my reasoning. If fossil fuels remain cheap for the next decade or two, we'll know that humanity has blown it.

To return to the characteristics of a country that is taking meaningful action to avert global warming, should I have included forestry in my list? Are there any other characteristics I've omitted?

I live in New Zealand where I observe no action whatsoever on any of my listed characteristics, except perhaps electricity generation. But we're in the fortunate position of being able to rely heavily on hydro-electricity. There has been some movement in recent years to introducing more wind farms, but these tend to meet resistance — they spoil the scenery, and there is not much of New Zealand that is not scenic.

RedBaron at 10:09 AM on 8 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

Tom,

While it may be true that biochar has limited use, again Citation needed for this quote:

"The effect of that decomposition, however, will be a reduced reduction in atmospheric CO2 from the natural take up of carbon once we reach zero net emissions, which in term increases the long term stable temperature increase we can expect from current CO2 emissions."

Keep in mind you are talking about the stable soil carbon fraction, not the active fraction, nor the biomass. I have yet to see anyone at all except you claim that increasing the soil stable carbon will somehow increase the long term stable temperature under any circumstances at all. Firthermore your hypothesis it is so backwards from how the soil and even the entire biosphere actually functions, please provide good citations.

Tom Curtis at 09:53 AM on 8 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

RedBaron @17, I have provided two citations for the decomposition of soil carbon to atmospheric CO2 already. Many more are easilly found by a search on google scholar. That decomposition will result in an increase in atmospheric CO2 levels relative to what they would be absent the decomposition. No further citation is needed.

Your request for a citation is nothing more than a tactic to avoid reasonable discussion of soil organic carbon. It is on a par with your deliberate, and libelous misrepresentation of the discussion of the subject @15 (since deleted by the moderators). It is also an evasion of the primary point, the very limited capacity of biochar by itself as a tactic against global warming.

RedBaron at 08:54 AM on 8 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

Tom,

"The effect of that decomposition, however, will be a reduced reduction in atmospheric CO2 from the natural take up of carbon once we reach zero net emissions, which in term increases the long term stable temperature increase we can expect from current CO2 emissions."

Citation needed. Please make it a good one too, no magical thinking citations please.

Moderator Response:

[DB] Inflammatory snipped. Keep it clean.

Tom Curtis at 08:22 AM on 8 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

ELIofVA @14, as of 2012, the total global production of plantation timber was 520 x 10^6 m^3 (download of PDF of report 3MB), or approximately 260 x 10^6 tonnes of wood. That wood in turn contained about 130 x 10^6 tonnes of carbon. In the same year, total human emissions amounted to 10.5 x 10^9 tonnes of Carbon. That is, if the world's entire production of plantation wood was turned to charcoal, and buried, you would sequester just 1.2% of the total annual anthropogenic emmissions. Inother words, biochar can at most provide one strategy among many to tackling climate change, and a relatively minor one.

One concern I have about sequestering carbon as biochar is that it is not permanent storage. Specifically, carbon in soil decomposes, releasing CO2 into the atmosphere. That decomposition may, or may not be temperature sensitive, but it certainly exists. The consequence is that there is an upper limit on the improvement of soil organic carbon by improved agricultural methods, which will vary by location, type of soil, drainage, and other factors. That does not mean such methods are not a good strategy for reducing CO2 content in the atmosphere, but they will not permanently offset CO2 emissions. (They will also need to be sustained more or less permanently a significant fraction of the increased soil organic carbon content will be returned to the atmosphere as CO2.) Biochar is said to be resistant to this type of decomposition, but it will not be immune to it. In the limit, biochar will decompose until its contribution to soil carbon does not exceed the equilibrium value of soil organic carbon in any particular environment. That will probably take thousands of years. The effect of that decomposition, however, will be a reduced reduction in atmospheric CO2 from the natural take up of carbon once we reach zero net emissions, which in term increases the long term stable temperature increase we can expect from current CO2 emissions.

knaugle at 06:20 AM on 8 April 2016

Factcheck: Are climate models ‘wrong’ on rainfall extremes?

The idea that all models are wrong is both correct and misleading. No model is 100% correct in any scientific or engineering discipline. HOWEVER, this argument is used to IMPLY that the climate models are useless, when it is abundantly clear they are of significant use and more and more look in aggregate to be more correct than some would like to see.

RedBaron at 01:42 AM on 8 April 2016

To meet the Paris climate goals, do we need to engineer the climate?

@ ELIofVA #14,

You wonder why carbon capture by biochar is not given more love by the climate activist? It's simple actually. The one industry even more taboo to mess with besides the fossil fuel industry is industrialized agriculture. Both need radical changes to be sure, but try arguing that and you will meet with massive opposition and obfuscation.

So basically those of us who are concerned about and working to develop carbon mitigation strategies are facing massive pushback. In some cases even from climate scientists. In the case of agricultural mitigation strategies there even is an unholy alliance between climate scientists and denialists, even ecologists in some cases. I could even give you examples from this website, but not willing to upset the apple cart too much. I still need the ability to post here. Don't want to lose that priviledge. This way at least I can post scientific studies and reviews from the minority opinion as they get published and I find them.

Just keep plugging though. Soon enough opinions will be forced to change. Agriculture will be forced to change even sooner than the fossil fuel economies due to soil degradation worldwide. Since the solution to both is carbon in the soil, one way or another it will happen.

Moderator Response:

[DB] Inflammatory snipped.

Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

Climate Science Glossary

Term Lookup

Settings

Term Lookup

Settings

Latest Posts

Recent Comments