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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.

Recent Comments

Comments 38601 to 38650:

Rob Painting at 17:07 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Klapper - you made this comment @61 - "The problem is that 0.18C/decade trend was boosted by the +phase of the IPO. The underlying anthropogenic signal is not that strong."

You neglected to account for the strong cooling of both the ocean and global surface from the light-blocking effects of sulfate aerosols ejected into the atmosphere by the 1991 Mt Pinatubo eruption. It goes to the heart of your claim highlighted above.

Klapper at 16:47 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

@Rob Painting #63:

Pinatubo would affect my 30 year trend, but not the 10 year (2000 to 2010). Mind the 10 year trends get a bit wobbly as opposed to the 30 year. However, looking at 10 year trends which avoid the Pinatubo problem, I can see that the current rate of sea level rise from tide guages is comparable to the rate of rise from '43 to '53. The complicating factor is net runoff/meltwater input into sea level rise during the recent and mid 20th periods. Because the planet is warmer over the last 10 years than in 1950, one would expect a higher rate of sea level rise from net melt runoff. What that means is there must have been a very large heat gain post mid '40's. Unfortunately the heat content data is pretty sparse back then and even into the '50's.

KR at 16:36 PM on 13 February 2014

Sea level rise is decelerating

jsmith - I believe the issue of concern is statistical significance. "Since 2004" is a very short time period, including the 2010 dip in sea level associated with La Nina, or "pot hole".

You really need to look at multi-decadal time periods to determine trends, as in Church and White 2011 who found "1900 to 2009 is 1.7 ± 0.2 mm/year and since 1961 is 1.9 ± 0.4 mm/year" and "For 1993–2009 and after correcting for glacial isostatic adjustment, the estimated rate of rise is 3.2 ± 0.4 mm/year from the satellite data and 2.8 ± 0.8 mm/year from the in situ data". They also note that "There is considerable variability in the rate of rise during the twentieth century but there has been a statistically significant acceleration since 1880 and 1900 of 0.009 ± 0.003 mm/year² and 0.009 ± 0.004 mm/year², respectively." (Emphasis added)

Short time periods, such as a single decade, are only going to show noise, not trends. While I don't subscribe to that particular journal and have not read the entire article, I fear that the paper is not properly evaluating the statistical significance of their results. If they can clearly support their hypotheses it will be interesting - but as it stands I see little support for such claims.

Rob Painting at 15:57 PM on 13 February 2014

Sea level rise is decelerating

jsmith - that paper has been doing the rounds on contrarian blogs, so you probably 'stumbled' across a contrarian blog.

I haven't looked at the research paper in detail, but the general slowing of sea level rise after 2004-2005 fits in with the sharp acceleration of heat uptake into the ocean during 2000-2005, and a slower rate of heat uptake thereafter. This 'slowdown' is perhaps the most striking feature of the Hiroshima widget.

The recent trend in sea level rise is consistent with ocean heat uptake, so we shouldn't be surprised that the recent trend in sea level rise has slowed somewhat too. A similar pattern seems to have occurred during the 20th century too - short-term accelerations and decelerations against a background of long-term acceleration in sea level rise.

There are a few other factors to consider too (decadal variations in continental storage of water mass, for example), but land-ice melt is accelerating and thermal expansion is not really going to be a factor throughout 21st Century - the disintegration of the vast ice sheets of Greenland and Antarctica will be.

Rob Painting at 15:35 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Klapper - 1976-1999, the last positive phase of the IPO, was interrupted by the large tropical volcanic eruption of Mt Pinatubo in 1991. - which cooled the Earth for several years and made an enormous impact on heat uptake by the ocean. See the graph below from Balmaseda (2013). This would have to be taken into consideration.

DSL at 15:04 PM on 13 February 2014

Sea level rise is decelerating

jsmith, take a look at why SLR might seem to be decelerating between 2004 and 2012. Between 2011 and 2013, SLR was rising at ~7mm per year. You'd do better to ask what caused that trough.

jsmith at 14:36 PM on 13 February 2014

Sea level rise is decelerating

Hello all. I recently stumbled upon a paper which states, in the abstract, that global mean sea level "rises with the rate of 3.2 ± 0.4 mm/yr during 1993–2003 and started decelerating since 2004 to a rate of 1.8 ± 0.9 mm/yr in 2012." This seems to indicate that sea level rise is decelerating globally (not just locally as was the case with Houston and Dean's paper). The paper can be viewed here. I would like to get some feedback on whether or not this does any damage to the apparently "consensus" view that sea level rise is accelerating.

scaddenp at 14:10 PM on 13 February 2014

A methane mystery: Scientists probe unanswered questions about methane and climate change

What the summary above misses but the linked article states is:

"since 2007, atmospheric methane has become more depleted in 13C (14), an indication that growth is dominated by 12C-richer wetland and ruminant emissions"

That kind of lets FF and methane hydrates off the hook to some extent.

dr2chase at 14:04 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

How much does this extra heat dumped into the ocean affect sea level rise?

Klapper at 13:20 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

@ HK #55:

"Of course a +IPO can enhance surface warming...."

I think you're starting to understand my argument. I accept there is an anthropogenic signal underlying the IPO cycle. However, the models have trouble with the IPO. They can't duplicate it so they ignore it and project that it should be warming right now at 0.20C/decade. After all, it's already warmed at over 0.18C/decade on a 30 year timescale and the CO2 level is higher then ever so it should be warming even faster than 0.18C decade, right?

The problem is that 0.18C/decade trend was boosted by the +phase of the IPO. The underlying anthropogenic signal is not that strong.

"...likely unprecedented heat uptake..."

That statement is probably not true since a rolling 30 year trend on the Church & White tide level sea level dataset shows an early peak of 2.13mm/year in the period 1933 to 1963 and 2.09 mm/year in the period 1980 to 2010. So if there was unprecedented heat uptake there should have been unprecedented sea level rise, unless you believe that the sea level rise before 1963 had higher levels of glacier melt than in the period 1980 to 2010.

Obviously those rates of sea level rise span both + and - phases of the IPO. However, if you look at shorter time spans (10 years) you will also find that current heat level gain is likely unprecedented, or not by much if it is. The sea level gain 1943 to 1953 was at 3.5mm/yr. 2000 to 2010 was 3.2 mm/yr., so there is nothing unprecedented about the last decade (Church & White ends at 2010 so I can't compare trends later than that to the '50s).

scaddenp at 13:11 PM on 13 February 2014

2014 SkS Weekly News Roundup #6

0.5 to 0.6W/m2 would be a better estimate. Forcings are recalculated to TOA for reasons outlined in I think the 2nd IPCC report. That does not mean you can make more or less direct measurements on which base that recalculation. However, with respect to TOA imbalance, he is right that the instrumentation cannot give a direct absolute measurement. However, the Argo network provides another way to do estimate it. Conservation of Energy dictates that you cannot have OHC increasing without an energy imbalance, and furthermore it gives a good way to estimate the imbalance in absolute terms.

KR at 12:56 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Klapper - The IPO is generally considered to be strongly driven by (among other things) teleconnections to the long term ENSO variations, as per Newman et al 2003.

Given a strong influence such as that, the IPO may wll be an add-on effect to the ENSO variations. And since over the long term ENSO variations cancel out, reddened ENSO teleconnections will too. Remember that correlation is not causation - variations in the IPO may very well be longer term lagged ENSO effects, rather than causes of atmospheric temperature variation in and of themselves.

As others have noted, you appear to be jumping around from thread to thread, topic to topic, in search of support for pre-existing convictions - rather than following the physical evidence to see where it leads. Once a particular unsupported assertion is shown not to hold (it's the sun!, the models are bad!, ENSO, now IPO) you jump to something else that might give your views support. The term for this behavior is confirmation bias.

I would recommend applying some of your skepticism to your own views, rather than making additional unsupported assertions.

Bob Loblaw at 12:40 PM on 13 February 2014

Australia’s hottest year was no freak event: humans caused it

Something nopbody has mentioned is that solar radiation reaching the surface is only one factor in how much energy is available to heat the overlying air (which is where air temperature comes from).

Nobody has mentioned the role of soil moisture, which plays a critical role in the division between thermal transfer to the atmosphere and evaporation (latent heat) transfer to the atmosphere. Dry soil means less evaporation means more thermal transfer means hotter air.

An less evaporation combined with warmer air often means less cloud, which lets more solar radiation through to the surface. HIgher solar radiation could be the result of the hot, dry conditions, not the cause of it.

And "more water vapour means more cloud" is not necessarily true, either. To form cloud, you need to take moist air and cool it to the condensation point. If the air is both more moist and warmer, it may be further from the condensation point (dew point temperature) rather than closer.

Klapper at 12:39 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

@ scaddenp #54:

If by "internal variability" you mean some random process, I disagree. The IPO cycle doesn't look random. And if it is not random, then what drives it?

KR at 12:38 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Bob Loblaw - Tamino's model is even simpler than that. The two boxes are representative of the atmosphere and the oceans, not different levels of the oceans. What he's doing is a (relatively) simple statistical correlation of forcings and temperature with a 6-month lagged ENSO index (lag from the lowest residual result as per Foster and Rahmstorf 2011) as part of the multiple regression.

The fit of even this simple energy balance correlation is quite remarkable.

[Source]

Bob Loblaw at 12:26 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Papy:

The 2-box model that Tamino uses has no "horizontal" in it, and very limited "vertical", so it can't include much in teh way of a physical process. When he incorporates an El Nino/La NIna process via the Souther Oscillation Index (SOI - a pressure indicator), all he is saying is that he can adjust heat transfer between his two ocean boxes (stacked vertically) according to the SOI. Including this adjustment in the model improves the fit, so that he had conclude that something (not sure what) about SOI/El Nino/La Nina cycles provides statistical explanation of the global surface temperature variation. It's a statistical correlation, not a physical explanation.

In contrast, the new study examines the physical process in much greater detail. It includes measurements of actual wind (not just a pressure index), reanalysis data (based on GCMs), and consideration of the physical processes. This is a much stronger methodology/confirmation than the statistical correlation at Tamino's.

Bob Loblaw at 12:13 PM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

mgardner and ianw01:

Thanks for the feedback. Perhaps it could be said that "all explanations are wrong, but some explanations are useful".

I do indeed manage to muddy the waters a bit by switching back and forth between force and shear stress, which have different units. SkS does not allow one to edit posts - perhaps a good thing as everything that is said is there for posterity. Shear stress is a concept that is difficult to put into simple words. I won't even try to go into strain.

..but to clarify mgardner's comment about the friction not depending on area - yes, as is easily demonstrated (if your brick isn't a cube) by turning the brick onto the smaller side (less area in contact with the ground) and seeing that friction (as measured by the pull on the rope) has not changed. The shear stress between the brick and the surface has changed, though. If the area is now half, then the shear stress has doubled - but with only half the area, the (shear stress X area) is constant... (to first order, as Ianw01 says).

Another place where shear stress shows up is on hill slopes. Stability depends on how large the shear stress induced by gravity is compared to the shear strength of the soil. As soon as the stress exceeds strength, the soil "breaks" and failure occurs.

We now return to our regularly-scheduled program.

barry1487 at 12:05 PM on 13 February 2014

Australia’s hottest year was no freak event: humans caused it

bruiser,

reference to "1990 - 2013" is not my comment.

I'm not sure you read my post clearly. I didn't "go back 80 years." All the records were pre-1909, and half of them were from the late 1880s. The reason a handful of them are little more than 80 years long is because the record truncates in the 1980 or 90s. I took your reference to pre-1900s and early 1900s as the basis for the selction.

The majority of sites are rural. For many of them I checked the siting of the weather station.

In the records I saw 1888 or 89 were often warm, occasionally warmest, but for the most part the average decadal warmth of that period was less than in the last decade or two of the record selected, whether the period stretched to recent temps or the 1980s/90s.

The topic we were discussing was the influence on solar exposure on the 2013 record. Your argument seems to have shifted to a general proposition that Australia is no warmer than it was more than a century ago. Your argument is based on very spotty data with obvious problems (and you have cited precisely one weather station), vague assertions about UHI (which the Australian record attempts to correct for), and absolutely no number-crunching or even casual testing of your opinion as I did. As the global record is quite robust on warming from 1880, with all large-region (continental-scale) records showing significantly warmer temps now than then, your assertions are not at all convincing. (Not enough data for the Antarctic, but it shows warming from the 1950s, corroborated by analysis from 'skeptics')

I provided a list for you of Australian weather stations with long records. Amongst them is a usable subset that roughly covers the periods you have nominated. The station numbers are provided, which you can type into a box at the BOM page you linked me to, and immediately bring up the annual min/max temperture series, each of which BOM will chart for you with a click. Why don't you select all that fit the period, cherry-picking none, and see for yourself? It's no more than two hours' work. Confirming the locations for those stations takes ony a little bit of googling. There is a site that briefly describes the locations, and plots them on google maps for you. Frequently the description I read was in the vein of "the station is located 650 metres from an unnamed sealed road."

If you take the trouble to investigate for yourself, I will repeat what I did the other day, this time noting down the weather station numbers and providing them to you so that you can cross-check that I selected appropriately.

To reemphasise a point, our excursion has little to do with the analysis given in the main article, which would be unaffected by pre-1910 data. If you're not sure why, I recommend reading it carefully.

Riduna at 11:51 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

Dr Abraham presents a very conservative view. Admittedly there are many areas where our knowledge is less than perfect but surely we know enough to know that we are already, to use a technical term, in dire shtuck.

Seems to me there is little, if anything, we can now do to retrieve the situation.

Chandra at 11:46 AM on 13 February 2014

2014 SkS Weekly News Roundup #6

Hi, apologies for a long question, but I would appreciate an opinion on a discussion I have had with a skeptic. I have understood there to be an energy imbalance and have seen it quantified as being about 1.7W/m2 currently and expected to rise. The skeptic, who appears to be a retired but experienced engineer, electronics perhaps, questions this. Here are some of his observations to me:

1. The properties of CO2 in absorbing and radiating IR over certain wavelengths has been precisely measured and is not open to dispute.

2. There is no doubt that a planet with an atmosphere of pure CO2 would be warmer than the same planet with an atmosphere of a gas that did not interact with IR.

3. From there on things are not “well understood” in the way that expression is normally used in science. The radiation imbalance does not come from measurement or observation of any actual imbalance. It comes from calculations based on notions including “radiative forcing” which can exist only in computer models and which is inherently incapable of being validated by observation or by experiment. ([Science of Doom] is not very complimentary about radiative forcing, though mainly because of its approximations.)

Its very, very hard for me to express how utterly ludicrous or irresponsible the idea of relying on unverified models would be regarded in any of the fields I have worked in. The fact that its widely done in climate science means that the subject just cannot be taken seriously. Its got the word science in its title but, whatever it is, it is simply not science. If learned people believe things about a physical system for which there is no physical evidence – and nothing that comes out of a model is evidence – then their learning has to be regarded as a form of theology. Its faith, not science.

And he goes on later, quoting from Science of Doom / IPCC:

“The radiative forcing of the surface-troposphere system due to the perturbation in or the introduction of an agent (say, a change in greenhouse gas concentrations) is the change in net (down minus up) irradiance (solar plus long-wave; in Wm-2) at the tropopause AFTER allowing for stratospheric temperatures to readjust to radiative equilibrium, but with surface and tropo-spheric temperatures and state held fixed at the unperturbed values”. (IPCC)

In other words, a concept that has no physical existence, that can exist only within computer models and which is incapable of being validated (and, equally, of being falsified). This give a lucid illustration of how climate science is not science, despite having the word in its title and wearing some of the clothes of science. If a concept cant be verified by experiment, it makes no difference how many learned people believe in it, it remains unverified.

A good principle when things are uncertain is to look for the simplest explanation that requires the fewest assumptions.

Instead of looking in the deep ocean, under the carpet, or elsewhere, to find what has happened to “the missing heat” that radiative forcing says should be there, climate scientists might well take a hint from Nature. With their models unvalidated, they cannot rule out that Nature is whispering: “Im sorry but the static temperature of the past fifteen years is simply because there is actually no imbalance between incoming and outgoing energy flows. The missing heat is nothing but a phantom conjured up by the approximations and errors in your models.”

I don’t have the necessary smarts to judge adequately what he says, but his mentioning of static temperatures for 15 years at the end indicates to me that he is not as “skeptical” as he would like to suggest. Can someone help untangle this web for me please?

ubrew12 at 10:41 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

Abraham asks "why does this have to be so hard?" I'm going to hazard a guess, take it as you wish. Loosely translated, the 2nd law of thermodynamics applied to a system (such as, a human) surrounded by much larger Environments, says "Your Environments are bigger than you". So it says you tend toward your Environments rather than the other way around. But what is the Environment? For Liberals, its Nature, for Conservatives, its humanity (i.e. the socioeconomic construction humanity has wrung from within Nature). For us as humans, it's probably a bit of both. Regarding the Conservative interpretation the phrase that applies is "there's the right way, the wrong way, and the Army way". That means: you may have a strong opinion about Right and Wrong, but the way that is going to apply is the Army way. You cannot ignore your socioeconomic Environment, even if it is poised to destroy Nature and with Nature, itself. That's why its so hard. The people you are asking to listen to the Natural Environment are fundamentally oriented to listen to their more immediate Socioeconomic Environment. To them, you are a 'tree hugger': you hug the tree rather than the stock market. It's your choice, but as we showed recently, the FED will make up whatever money it needs to support the stock market. Of course this matters: trees have no such recourse. The reason this is so hard, is that you're trying to convince people that the real environment still matters, is still powerful, and has the ability, as in days of old, to make your life miserable if ignored for long. But they are increasingly trained to think that's not true, that humanity exists outside of Nature, and is the exception to it. The reason this is so hard is that, in the short term, they are right. Of course, in the long term, even Nature balances her books.

HK at 09:57 AM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Klapper 51:

Of course a +IPO can enhance surface warming just as –IPO can enhance surface cooling as more heat is released from or stored in the oceans, but there are very good reasons to believe that its impact on the long-term climate is close to zero compared to anthropogenic greenhouse gases.

Look at the bottom frame in figure 1 in the blog post.
The IPO was negative until 1920, positive until 1945, negative until 1978 and then positive until 2000, in other words a typical oscillation around an average value without a clear trend.
The temperature in the top frame shows a very clear trend over the same period, so whatever caused that, the IPO cannot have been a factor when we consider the entire period from about 1910 to 2000.

If IPO was as important as you seem to think it is, the negative IPO should have had a cooling effect between 1945 and 1978. In that period, the global sulphur emissions tripled, from about 25 to 75 million tonnes, so the negative IPO got a lot of “help” from global dimming.
Why was the temperature more or less flat despite two large negative impacts? Maybe because one of them wasn’t as large as you seem to think?

The next period (1978-2000), with a positive IPO and a very clear warming trend, coincides with a continued growth of the greenhouse gas forcing and a moderate reduction of the sulphur emissions (global brightening). It’s worth noting that the oceans continued to accumulate a lot of heat, so the main driver of the surface warming must have been an external forcing even if the positive IPO gave a small contribution.

Regarding the period after 2000, I find it interesting and revealing that it takes “unprecedented” trade winds and likely unprecedented heat uptake in the oceans to slow down the surface warming, even with some help from a weak sun and (possibly) Chinese aerosols. And maybe the surface warming hasn’t slowed down that much after all.

Greenhouse gases are still the most important factor controlling the Earths climate!

scaddenp at 09:56 AM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Klapper, "could the +IPO have enhanced the warming between 1975 and 2000?"

Firstly, the IPO is an index rather than process and would appear to be a metric recording the superposition of a number of oceanic processes. If you restate the question, "could internal variability enhanced the post 1975 warming, (esp 1992 to 2006)" then yes, as noted it in Rahmsdorf 2007.

scaddenp at 09:24 AM on 13 February 2014

2014 SkS News Bulletin #1: Keystone XL Pipeline

I doubt that you would find much argument amoungst climate scientists for the desirability of a pigovian tax on carbon (the "Hansen tax"). Except that it is more expensive to administer than simple ban on new FF infrastructure.

There have been a no. of studies on cost of mitigation versus cost of adaption. (eg the Stern report). If the study considers impacts in line with the IPCC WG2 report, then mitigation is economically desirable. Further discussion on this could perhaps take place here.

gws at 09:24 AM on 13 February 2014

A methane mystery: Scientists probe unanswered questions about methane and climate change

biomass burning provides at least a partial answer

Russ R. at 08:52 AM on 13 February 2014

2014 SkS News Bulletin #1: Keystone XL Pipeline

chriskoz,

I'm quite familiar with the tragedy of the commons (from a few years of economics study at both the undergraduate and graduate levels), but I don't believe your analysis of solutions is complete.

You listed:

some form of governmental regulations,
individuals can cooperate to conserve the resource in the name of mutual benefit
conversion of common good into private property, giving the new owner an incentive to enforce its sustainability.

First of all, you omitted a perfectly valid solution:

4. Do nothing (if the costs of correcting the externality exceeds the costs of the suboptimal outcome).

But I'll leave that one aside for now.

Second, after excluding solutions 2 and 3, you picked up solution 1, "some form of governmental regulations" and jumped straight to "banning the further proliferation of FF infrastructure" without considering that there may be other forms of "governmental regulations" that are less drastic (and impose fewer externalities of their own).

For example, a Pigouvian tax.

As above, to avoid argument over the appropriate figure for the social cost of carbon (SCC) let's just use the $36/tC figure adpoted recently by the White House. Insert a different value if you prefer.

We've already established above that the differential CO2 emissions between the tar sands oil coming through the pipeline and conventional light crude available in the US Gulf Coast is 0.121 tCO2/bbl (559.6 kgCO2/bbl vs. 438.6 kgCO2/bbl). That works out ot 0.033 tC/bbl. Applying a tax of $36/tC results in a charge of $1.19 per bbl to the outflow from the pipeline to correct the "externality" of using tar sands oil instead of conventional oil.

Problem solved.

scaddenp at 08:32 AM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Klapper I have responded on aa index in a more appropriate thread, here.

scaddenp at 08:30 AM on 13 February 2014

It's the sun

Over here Klapper postulated a link to climate from AA index.

Klapper, lets see if I have understood this:

You are postulating a climate effect from geomagnetic activity (or other) for which the AA index is a proxy. Furthermore, you are implying that variation in this phenomena is more effective climatically than variations in radiative energy from the sun (ie TSI, measured directly from satellites since 1979). As a corollary, you are also postulating an undiscovered negative feedback or process that stops the extra longwave irradiation due to enhanced greenhouse effect from warming the earth.

Your lag proposal postulates a process where the response can increase after the driving force has decreased.

Frankly, call me skeptical. What is missing from your arguments is evidence for plausable physical processes. Rather it seems further evidence that you have uninformed a priori position on AGW and looking for supporting arguments while ignoring the overwhelming support for a better model.

chriskoz at 07:47 AM on 13 February 2014

A methane mystery: Scientists probe unanswered questions about methane and climate change

In the figure by Andy@2, the biggest surge of emmisions happened at N mid-lattitude around 2002-2003. That was immediately followed by the biggest drop in the following year at the same location (is it really the same 'locality' in the raw data or just happens to be in the same band but somewhere else, e.g. NAmer vs. Europe/Asia?). These are the two biggest anomalies on this figure. Has anyone looked at explaining this? Do we have a 'smoking gun' here (but do not understand the processes involved yet) or is it just random noise from naturaql variabilities?

Papy at 07:45 AM on 13 February 2014

Unprecedented trade wind strength is shifting global warming to the oceans, but for how much longer?

Last year, Tamino estimated the influence of ENSO with a 2-box model, NASA forcings and SOI data for ENSO.

Could someone explain me what's the difference with this tremendous new study ?

gws at 07:32 AM on 13 February 2014

A methane mystery: Scientists probe unanswered questions about methane and climate change

thanks, witsend @10 for pointing out that paper. However, the study was about live, standing trees, not dead/decaying trees. Its sample size was very small, the variability (range) near 100% in most cases, and its extrapolation (from the mean) rather bold. If real, there is no reason to believe the source (~20 Tg/yr, thus relatively small) would not have existed before 2007/08, thus cannot explain the current rise.

ubrew12 at 06:44 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

In the '2014 SkS Weekly News Roundup #6' there was an article 'How to convince your friends to believe in climate change' that seemed fairly helpful. Shortly, avoid trotting out Scientific facts or Scientific consensus. Come from your heart, state that the issue is important to you. Then offer 4 reasons why you 'came around': 1)taking action is like taking insurance, 2)taking action will involve nuclear power, 3)since illness hits people where they live, talk about how tropical illnesses are expected to spread if we do nothing, 4)mention that the US Department of Defense considers AGW to be a top threat. If I get the psychology right, you aren't talking to people who care about Nature, and have probably already pegged you for a 'Tree Hugger'. These people are prudent and buy insurance policies to cover most things, they like nuclear power because they know it irritates the 'greenies', like most people they feel illness in their bones, and they are apt to salute whenever you mention the Military. Good Luck!

scaddenp at 06:23 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

What Russ R is pointing to for "unintended consequences" to my mind is actually the certainity of pursuing policies favoured by business lobby groups which nearly always turn out badly - namely using subsidies. That these will have unintended consequences is a near certainity not an uncertainity. I accept the need for government subsidies on health and education but in every other arena, they tend to be a disaster. "Dry" governments of both left and right here (NZ) in the 90s ended subsidies right across the economy - a good move. 73% renewable generation and no subsidy in sight. First step is kill subsidies on fossil fuel, second step is ban new generation using FF and let the market decide the next best source. The obvious foreseeable consequence is that you will pay more your energy. However, you are going to pay more future energy one way or the other - if not directly, then through your insurance bill if not worse.

Rob Honeycutt at 05:57 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

CBD @14... But I think all that is a function of how many conservatives are processing the problem. Scientists say we have this looming issue that can have extremely severe consequences in 75-100 years. In the minds of many people that just doesn't compute at all. When you say, "75-100 years" you might as well be telling them the problem is on another planet. And then we're saying we need to adjust markets and taxes to compensate for this problem that exists on another planet.

SteveFunk at 05:48 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

I tend to agree with Russ R. The cost of the baby steps we have taken to reduce emissions are going to be insignificant compared with what we need to do to stay at 400. The costs are up front. The benefits and costs avoided are a number of decades in the future.

HOWEVER, when I went to look for a specific example, it went the other way. The five year ownershop costs for a Nissan Leaf, according to Edmunds, are about $4000 less than the five year costs of a Toyota Corolla. And that doesn't include the $7,500 tax subsidy that the leaf gets. For someone who just needs a commuter car, the Leaf is a good deal.

CBDunkerson at 05:42 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

This just doesn't match my experience. So far as I have seen, nearly everyone who contests AGW does so on the basis of disbelieving one or more of the three 'known and not controversial' items listed in the OP.

Yes, it would be wonderful to have a logical discussion about risk and uncertainty and the best course of action in the face of proven realities... but that just isn't anything remotely similar to what I see. I'd estimate maybe one 'skeptic' in a thousand accepts the basic realities of global warming and is only questioning the details. Frequently, even those who actively say that they accept the science will 'slip' and repeat the most demented illogical arguments imaginable. Thus, I don't believe this is a 'rational debate' at all. Getting to that stage would require a significant change in beliefs by the vast majority of climate 'skeptics'.

To take the Inhofe example, no it doesn't seem likely that he has a 'villain lair' where he plots new ways to destroy the planet, but he also certainly isn't anything like the 'rational skeptic' portrayed in this post. No, he is out there saying that human greenhouse gas emissions cannot cause warming. That volcanoes caused CO2 levels to rise. That AGW is all a big hoax. Et cetera. And he isn't alone. That is standard fare from Fox News, Limbaugh, virtually every GOP politician, and the rest of the 'conservative' (an even less accurate term than 'skeptic') faction in the U.S. Maybe it is different in other countries, but I for one would be unspeakably relieved to see anything like the level of sanity this post suggests exists.

ubrew12 at 05:39 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

Russ R.@11: google "ray kurzweil solar will power the world in 16 years". It's not my idea. It's an extrapolation of a 20 year trend. I certainly hope you're right about SLR, but nature reveals itself in exponential functions all the time, and I can think of no physical reason why it wouldn't apply with SLR as well. The main thing, however, is the uncertainty: we're messing with a form of matter whose flow behavior gifted the English language the word 'Avalanche'. That's like taunting a Shark.

ubrew12 at 05:34 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

Composer99@10: To tack on to your point, and add to my own (above), here, in red, is the shape of sea level rise from ice sheet melting, in the last 10 years:

http://www.skepticalscience.com/pics/SLRIcesheetcontributions-VanDenBroeke2011.jpg

It's an exponential curve, as would be expected in a situation like this, and I found that a reasonable approximation to it is: Cum SLR = exp((year-2000)/4.1). Assuming this trend continues out going forward, then SLR hits 5 feet by 2030, and 57 feet by 2040!! I can't believe it'll happen that fast, but I also can't believe it'll trend linear either. We are in uncharted waters: a tipping point has been passed, in 2000, and nobody noticed. Ice sheets are melting exponentially, as one would expect, and the nonlinear exponential function is no help when it comes to prediction accuracy.

Russ R. at 05:27 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

ubrew12:

"Suppose that rate doubles every ten years? Then by 2100, 17 feet will have been added,..."
"Only 8 more doublings and Solar PV could power the World."

Your technique of extrapolating exponential growth into the future... you might want to rethink it. It doesn't work so well in the real world.

Composer99 at 05:15 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

Russ R:

In my view, Dr Abraham is overstating the uncertainties regarding global warming - or rather, that he has not clarified enough the distinction between the uncertainty regarding ultimate outcomes and uncertainty regarding timeframes and severity.

For example, analysis of paleoclimate data suggests that, if CO2e were to stop dead at 400 ppm, we would still be in for substantial sea level rise due to the melting of the large ice sheets in Greenland and Antarctica (e.g. see here for an estimate of sea level, relative to the present, in the last interglacial period). If that emissions continue unabated, we can be extremely confident that given time, all the ice would melt away eventually.

The ultimate outcome of unabated greenhouse gas emissions - massive sea level rise following the melt-off of the continental ice sheets - follows of necessity from the assumption of unabated emissions and what is presently known regarding cryosphere response to global warming. There is, effectively, no uncertainty regarding the ultimate outcome: if we warm the planet enough we could end the current ice-house state of the Earth and return it to an ice-free, hot-house state. This would entail a sea level rise of some tens of metres.

What is uncertain is how long it will take to get there. A higher climate sensitivity and more sensitive ice sheet response, for example, would suggest such sea level rise would occur very rapidly, in geological terms at least, and vice-versa for lower sensitivity and less sensitive response.

As the ultimate outcome of unabated warming with respect to sea level rise is not in doubt, we must sooner or later look to decarbonisation and, if technology permits, carbon sequestration in order to avoid it (on the assumption that multi-metre sea level rise is undesirable).

I could go on about other consequences of global warming - impacts on (agricultural) plant growth and distribution, heat stress on mammals, and so on. The ultimate consequences of unabated warming are, in my view, very cut and dried; the uncertainty lies in how quickly they will arrive (and/or how they will be distributed spatially, in the case of, say, changing weather patterns).

What is more, the ultimate outcomes of warming are not avoidable just by virtue of climate sensitivity being, say, on the low end of IPCC estimates. All that means it that it takes longer to get there, assuming unabated warming.

TL,DR: Assuming we want to avoid the ultimate outcomes of global warming, we have to abate it. And, as many people have pointed out in many articles and comment threads here and elsewhere, while there may be reasonable points of disagreement on how quickly and extensively to ramp up decarbonisation and sequestration, uncertainty is not our friend.

----------

As some final notes, with respect to the Globe & Mail article, I find the following paragraph very telling:

It is also the latest sign of turbulence in the green-energy industry after the global recession reduced the need for power and an uncertain economy made less costly conventional electricity more attractive than pricey renewables.

Leaving aside the fact that in Ontario about half of power generation is from nuclear power, the remaining proportion of "conventional" (that is, fossil fuel) electricity is only "less costly" than renewables because of (a) enormous direct and indirect subsidies paid out by various levels of government (in effect, we citizens pay fossil fuel power generators for the privilege of having lower numbers on our bills and at the fuel pumps), and (b) the rather large externalized costs of fossil fuel combustion (namely, global warming and its attendant consequences), which are not currently well-reflected in the prices we pay for, say, electricity from fossil fuels. (This latter point is the basis for arguing for carbon taxes, fee-and-dividend systems, and the like.) Their lower apparent cost compared to renewables is, in effect, an illusion.

Further, the Globe & Mail article suggests that the growth of renewable energy in Ontario is not falling victim to some perverse consequence of pursuing renewable energy per se, but rather to such things as retrenchment during economic stagnation and what I assume would be a normal driving down of prices due to over-supply ("After a decade of rapid expansion, during which Ontario badly wanted to increase the power supply as it shut down coal plants to cut greenhouse-gas emissions, the recession drove down demand and the province wound up with an electricity surplus"), austerity measures and/or perception-management by the government ("The still-shaky Ontario economy has also made it politically harder to justify the cost of subsidizing green power both to cash-strapped households and industrial enterprises for whom power is a major business expense"), and competition ("The rise of low-cost solar panel manufacturers in China has put further pressure on Western-based companies").

Rob Honeycutt at 05:14 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

What I often wonder is whether much of the conflict on this issue revolves around how people process risk differently. And that may play into the whole liberal/conservative aspect of it as well.

My sense is there are people who respond to immediate risk and those who respond to long term risk. I think you see it playing out right now in the US in terms of the national debt. Conservatives view the debt as this problem that must be addressed immediately. Liberals tend to lean toward saying, the debt is important but is something that can addressed over a longer period. It's short term vs long term risk response.

The same thing plays out relative to climate where conservatives tend to focus on economic risks related to addressing climate change now, whereas liberals tend to look at the longer term risks of not addressing climate change.

The nit for all of this is that, honestly, I believe addressing the long term issue can have net economic benefits now.

Rob Honeycutt at 05:03 AM on 13 February 2014

Discussing global warming: why does this have to be so hard?

Russ... I would also add, unintended consequences going to happen one way or another, regardless. Renewables are on an unrelenting march toward cheaper and cheaper energy. Any problems that are going to rise from this are going to rise whether we manage that process or choose to just let it happen.

What would be a shame would be if we did have all the technologies and abilities to address climate change but acted too slow to make a difference. That's a very real possibility as things are going right now.

william5331 at 04:24 AM on 13 February 2014

A methane mystery: Scientists probe unanswered questions about methane and climate change

Since methane is an energy source for a range of bacteria and bacteria can multiply at prodigious rates if the conditions are right, perhaps we are looking for a sink involving methane using bacteria to explain the missing methane. Also the comment (5) that the rate of a chemical reaction is very much dependent on the concentration of the reactants is very much to the point.

Incidentally, methane is a lot more powerful than 50times Carbon dioxide. A recent figure given in the NSIDC was X86. Reverse engineering the figures suggests as much as X140

http://mtkass.blogspot.co.nz/2013/03/the-real-strength-of-methane.html

witsend at 03:51 AM on 13 February 2014

A methane mystery: Scientists probe unanswered questions about methane and climate change

Perhaps the methane increase is due to dying trees. Interesting that the jump began in around 2008, which is the year I first noticed that they are all dying. From this post: http://witsendnj.blogspot.com/2012/10/spill-scarlet-rain.html

New information also comes from the Yale School of Forestry, where researchers have discovered high levels of methane emissions from trees that are dying from fungal infection, which they claim is a worldwide phenomena, and yet they cannot (in fact, don't even try to) explain WHY trees that are only at the beginning of maturity (80 to 100 years old) are dying prematurely all over the earth. I suspect they do not appreciate the implications of their own discovery beyond the acceleration of climate change. From SummitCountyVoice:

Sixty trees sampled at Yale Myers Forest in northeastern Connecticut contained concentrations of methane that were as high as 80,000 times ambient levels. Normal air concentrations are less than 2 parts per million, but the Yale researchers found average levels of 15,000 parts per million inside trees.

“These are flammable concentrations,” said Kristofer Covey, the study’s lead author and a Ph.D. candidate at Yale. “Because the conditions thought to be driving this process are common throughout the world’s forests, we believe we have found a globally significant new source of this potent greenhouse gas.”

“If we extrapolate these findings to forests globally, the methane produced in trees represents 10 percent of global emissions,” said Xuhui Lee, a co-author of the study and Sara Shallenberger Brown Professor of Meteorology at Yale. “We didn’t know this pathway existed.”

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