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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 26901 to 26950:

Tom Dayton at 10:42 AM on 14 November 2015

Models are unreliable

Hawkins and Sutton are about to publish a peer-reviewed article explaining why and how choice of reference period is important when comparing model projections to observations. A pre-publication version is available now.

sifeher at 03:43 AM on 14 November 2015

Video: Drought, Climate, Security, and Syria

Thank you for citing this interesting and timely article. The Middle East wars may not have been caused directly by global warming, but it is certainly contributing to the migration of millions from that region and also from Africa. It would be good to call this to the attantion of the G20 meeting in Istambul next weekend and before the Paris climate summit.

Lloyd Flack at 20:10 PM on 13 November 2015

G R A P H E N E

I'm worried by the possibilty that cells could be damaged by the phsical presence of sharp particles in similar ways to asbestos. For now I think it wight be a good idea to use similar precautions to those used in dealing with asbestos. There is the potential for cancers which take a long time to develop,

Trevor_S at 18:24 PM on 13 November 2015

Lamar Smith, climate scientist witch hunter

The strain of anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge.” ― Isaac Asimov

0^0 at 17:21 PM on 13 November 2015

The Skeptical Science temperature trend calculator

I'm still a bit new to R and ARIMA - and I have quite some difficulty in locating where in arima output you actually get those values "1.52+-0.404"

"Nick Stokes at 09:13 AM on 29 August, 2013

KR,

Thanks, I should have looked more carefully at the discussion above. I did run the same case using ARMA(1,1)

arima(H,c(1,0,1),xreg=time(H))

and got 1.52+-0.404, which is closer to the SkS value, although still with somewhat narrower CIs."

I may have problems in getting my input data right - or processing / reading it.. Or both.. :(..

Should those numbers be available from someplace here in this output?

Call:
arima(x = ds_hadcrut4_global_yr_subset$value, order = c(1, 0, 1), xreg = time(ds_hadcrut4_global_yr_subset$value))

Coefficients:
ar1 ma1 intercept time(ds_hadcrut4_global_yr_subset$value)
-0.5092 0.7643 -0.2845 0.0168
s.e. 0.2951 0.2214 0.0351 0.0018

sigma^2 estimated as 0.00739: log likelihood = 35.09, aic = -60.18

ds_hadcrut4_global_yr_subset$value contains - or at least should- yearly averages from monthy anomalies 1980 - 2013..

Thanks!

uncletimrob at 17:07 PM on 13 November 2015

Why were the ancient oceans favorable to marine life when atmospheric carbon dioxide was higher than today?

Sorry, but your question asks the impossible because 300 million years is so big compared to anything we as humans have experienced.

Its the same scale as saying something happend 1 year ago, and then asking about a year and 1/10th of a second ago.

Geologic time scales are hard to comprehend and of course can only be very general and never down to the nearest year. I'd suggest that the "error" is a few tens of millions of years, but will be happy to be corrected by somenone with more expertise than me.

Tom Curtis at 16:26 PM on 13 November 2015

G R A P H E N E

Some graphene related MSDS:

Graphene

"Potential Acute Health Effects: Slightly hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation.
Potential Chronic Health Effects:
CARCINOGENIC EFFECTS: Not available.
MUTAGENIC EFFECTS: Not available.
TERATOGENIC EFFECTS: Not available.
DEVELOPMENTAL TOXICITY: Not available.
The substance is toxic to upper respiratory tract. The substance may be toxic to cardiovascular system. Repeated or prolonged exposure to the substance can
produce target organs damage."

Graphene films on SiO2/Si substrate:

"Potential Health Effects: Generally not hazardous in normal handling, however good laboratory practices should always be used."

Graphene oxide:

"EMERGENCY OVERVIEW: THIS MATERIAL MAY BE AN IRRITANT TO EYES, SKIN OR RESPIRATORY TRACT.
Potential Health Effects: Eyes – may cause eye irritation. Skin – may cause skin irritation. Respiratory tract/inhalation – may cause irritation.Ingestion – not hazardous in normal industrial use circumstances. Cancer – natural graphite may contain small amounts of impurities of 0% - 1% crystalline silica, which is listed as a Group 1 carcinogen by IARC and as a suspected human carcinogen by ACGIH. Inhalation of high concentrations of crystalline silica over prolonged periods of time has been linked to an increase in lung cancer. Inhalation of high concentrations of crystalline silica over prolonged periods of time may also cause silicosis. Inhalation of high concentrations of graphite dust over prolonged periods of time may cause pneumoconiosis."

Reduced Graphene Oxide:

"EMERGENCY OVERVIEW: THIS MATERIAL MAY BE AN IRRITANT TO EYES, SKIN OR RESPIRATORY TRACT.
Potential Health Effects: Eyes – may cause eye irritation. Skin – may cause skin irritation. Respiratory tract/inhalation – at high concentrations may cause irritation. Ingestion – not
hazardous in normal industrial use circumstances. Cancer – natural graphite may contain small amounts of impurities of 0% - 1% crystalline silica, which is listed as a Group 1 carcinogen by IARC and as a suspected human carcinogen by ACGIH. Inhalation of high concentrations of crystalline silica over prolonged periods of time has been linked to an increase in lung cancer. Inhalation of high concentrations of crystalline silica over prolonged periods of time may also cause silicosis.
Inhalation of high concentrations of graphite dust over prolonged periods of time may cause pneumoconiosis.
Physical Hazards: Graphite is electrically conductive. Care should be taken, therefore, to avoid accumulations of graphite dusts or powders in places where these accumulations could cause shorting of electrical switches, circuits or components."

Graphene Films, TEM grid:

"Potential Health Effects: Generally not hazardous in normal handling, however good laboratory practices should always be used."

The upshot appears to be that there is no evidence of significant toxicity from graphene itself, although doping agents can make it toxic. It does act as an irritant (as does any fine dust), but that is not a major problem.

Riduna at 12:55 PM on 13 November 2015

G R A P H E N E

Katesisco @ 9– The US Materials Safety Data Sheet warns against inhalation of pure graphine particulates (dust) which causes cellular damage in the lungs resulting in emphysema. It describes skin and eye contact with dust as a mild irritant and gives no information on carcinogenic effects, if any. More work on its industrial use is needed since it does not address graphene compounds.

Moderator Response:

[PS] A reference would help please.

Digby Scorgie at 11:25 AM on 13 November 2015

Lamar Smith, climate scientist witch hunter

Science-haters in positions of power imperil democracy.

wili at 08:41 AM on 13 November 2015

Why were the ancient oceans favorable to marine life when atmospheric carbon dioxide was higher than today?

" As far as we can tell, looking back over the last 300 million years"

When I see these kinds of claims, I always want to know--was there a more rapid acidification event 301 million years ago? Or is this just as far back as we can accurately reconstruct acidification events at this point?

Does anyone know which of these scenarios we are dealing with here?

KR at 02:03 AM on 13 November 2015

G R A P H E N E

Regarding ultracapacitors, batteries, etc - the best solution for electric transportation will likely be a mix. Hybrid electric storage designs have a lot of advantages.

High energy density but slow storage: Li-Ion batteries, Zinc-air batteries (very high density), fuel cells, whatever comes down the road. These have limitations on charge and discharge rate, which among other things really limits regenerative braking. If the batteries cannot accept energy at the rate of braking, that energy is lost (to normal brake pads, big resistors, etc) as heat.
High power density but limited storage: ultracapacitors can charge/discharge in milliseconds, but with lower energy density they aren't good candidates for primary storage (yet).

A combination of the two permits complete regenerative braking and avoids oversizing battery packs for acceleration - a win-win situation.

Ultracapacitors are currently in use on about 1 million 'micro-hybrid' cars to run stop/start cycles, where the fossil fuel engine is shut down when stopped instead of idling in traffic.

MA Rodger at 20:28 PM on 12 November 2015

G R A P H E N E

Graphene is a technology that is still in the laboratory and like so many similar technologies is surrounded by all the hype which is employed to attract the attention of the movers & shakers. The technology is at the point of demonstrating laboratory devises comparable in weight to lead-acid batteries but being capacitors rather than batteries they have blindingly fast charge/discharge rates. This achievement allows talk of matching lithium-ion batteries for weight, although such batteries are themselves also a developing technology. Yet rapid charging rates make the total on-vehicle capacity of graphene capacitors (and thus its weight) a different priority than it is for batteries. I don't think graphene is being seen anywhere as powering airliners. However there is another very interesting applcation mentioned in this SkS post. Being made of carbon rather than lead, the technology could be more amenable to scaling up in capacity to allow the useful storage of renewable power and enabling that 24/7 supply.

bozzza at 19:50 PM on 12 November 2015

G R A P H E N E

@ 11,

So not even graphene will make electric airplane travel possible?

bozzza at 19:46 PM on 12 November 2015

G R A P H E N E

The issue with subsidies for fossil fools is: ..THAT OF GREASING THE PALMS OF INDUSTRY...aka: TOO BIG TOO FAIL!

Power runs industry and prevents anarchy and holds all borders etc...(.. not to mention preventing house, and therefore massive city-wide, fires from candle-lit after dark shin-digs!!_

Moderator Response:

[JH] The use of "all caps" constitutes shouting and is prohibited by the SkS Comments Policy.

ubrew12 at 14:50 PM on 12 November 2015

Lamar Smith, climate scientist witch hunter

If Lamar Smith has a problem with the modern temperature record, he should contact the BEST survey. Easiest way to do so is to contact their funders: the Koch Brothers. Surely Smith has the Koch Brothers on his speed-dial...

Mark Welsch at 13:54 PM on 12 November 2015

G R A P H E N E

If we could get rid of subsidies for coal and other fossil fuels, this and other types of green electric generation and storage would happen more quickly. Or, we could help Dr. James Hansen.

Dr. James Hansen, from NASA says, “Most impressive is the work of Citizens’ Climate Lobby… If you want to join the fight to save the planet, to save creation for your grandchildren, there is no more effective step you could take than becoming an active member of this group.”

A revenue neutral fossil fuel tax (that increases every year) and dividend law would create 2.1 million jobs in ten years - not hurt the economy.

To learn more about the tax carbon, pay people plan, (and hopefully join us) click here: https://citizensclimatelobby.org/carbon-fee-and-dividend/

michael sweet at 12:04 PM on 12 November 2015

G R A P H E N E

Andrew:

The fastest trains in the world are electric. You just have to think differently. Many jobs currently done by trucks could be done using electric trains. Trucks could do the short haul. Just because it is not how we do it now does not mean that it cannot be done.

scaddenp at 11:49 AM on 12 November 2015

G R A P H E N E

" FFs are the only realistic sorces of energy in those scenarios."

If you are only going to liquid fuels for planes and trains, then biofuels are an alternative. Lot of work going into woody feedstock. Just a little matter of pricing...

AndrewMF at 10:55 AM on 12 November 2015

G R A P H E N E

"The Oil Industry will only flourish as long as constraints on use of EV’s remain in place. They are vehicle price (at present often double for EV’s), refueling time (over 40 hours from standard mains) and kilometres per charge (usually under 200 km."

Here in Australia, there are a few EV's at attainable prices: The Leaf and the BMW i3 for example. Both of those vehicles charge to full in a few (6-8) hours from standard 240v 10A power points, so easily overnight. Not sure where you found 40 hours? With a 32A EVSE, the i3 charges in under 4 hours, and with the DC charge option it charges to 80% in 20 minutes. (well, once DC chargers become common)

Less than 200km range is the current norm, and it does cause range anxiety until you actually use an EV. Most commuters travel way less than 100km in a day, so having less than 200km is hardly a big issue for most. The owner involvement in refuelling the EV is a minute at home (just plug it in) Compare that to your FF vehicle. If your trip is 50-60km, why would you need to lug around a large vehicle with a 450km battery like the Tesla?

I'm sure that as battery tech improves we will see greater range on these EV's. Nissan is apparently about to release an extended range Leaf to solve the range anxiety issue.

chriskoz at 10:21 AM on 12 November 2015

G R A P H E N E

Ken in Oz@8

I would not be so optimistic about all electric transport including trucks & planes.

For starters, the energy density of 10kF supercapacitor weighing as muchs a "paperback book" (let's give it a mass of half pounr or 250g) and maximum voltage say 3V (most supercapacitor support even max breakdown voltage of 2.7V and this one seems no exception, Riduna please confirm), the energy yield is:

1/2 * 10kF * (3V)²

which is 45kJ per 250g or 0.18MJ/kg (I think I've overestimated it but Riduna might provide that detail, missing in the original OP)

which is still behind the existing battery technologies (e.g. Li-Ion up to 0.875MJ/kg) and far behind the miraculous energy density of burning petrol (44.4MJ/kg) or gas or other liquid FF.

https://en.wikipedia.org/wiki/Energy_density

So while graphene may be an important step forward in energy storage technology (I'm especially excited about the prospect of superfast recharge of say 15mins in an average EV), it is not a universal solution to all transportation at this stage. You cannot load 100 tons of charged graphene on board of a jumbo jet and expect it to fly a few Mm between continents or fill in a 100t truck or 1000t train and expect it to roll for 1 Mm accross the desert. There is simply not enough energy for that. FFs are the only realistic sorces of energy in those scenarios.

Riduna at 09:16 AM on 12 November 2015

G R A P H E N E

chriskoz – I don't know. The literature does not show how graphene mass is calculated. It may be as you suggest that mass can only be calculated for a 3D material, or it may be due to each hexagonal containing only 2 atoms. I have e-mailed Manachester University seeking clarification.

katesisco at 00:10 AM on 12 November 2015

G R A P H E N E

http://www.nano.northwestern.edu/research/carbon-nanotubes-and-graphene

Perhaps I am mistaken but if carbon nanos are graphene, then how is the toxicity to human cells going to be overcome?

Moderator Response:

[PS] fixed link, but carbon nanotubes are not graphene. A link concerning potential toxicity from applications as discussed would be more useful.

Ken in Oz at 21:06 PM on 11 November 2015

G R A P H E N E

When coated with Lithium it becomes a superconductor, having no resistance to an electric current at room temperature.

As Ed pointed out - 5.9K - a wee bit cooler than most rooms. Still, it's good to know there is innovation in the pipeline with the potential to make electric ships, trucks and planes as well as cars, solar homes and businesses not merely possible but the superior option. Not all innovation makes it to commercialisation let alone ubiquitous utilisation but there is no sign that the well is drying out.

Tom Curtis at 19:28 PM on 11 November 2015

Climate's changed before

JH inline @506, NN1953VAN-CA previously linked to the data Alley et al (2000), ie, GISP2, and Petit et al (1999), ie, Vostok, as the data justifying the claim. However, he clearly misrepresents it. Specifically, he claims temperature variations of 3 degrees for Vostok, GISP2 and global temperature series within the last 300-400 years. Vostok shows a maximum 0.36 and minimum -1.84 variation from the most recent value after 1600 AD, giving a maximum variation over that period of 2.2 C. GISP2 shows a maximum variation from the most recent value of 0 C and a minimum -0.4985 C over the same period, giving a maximum temperature variation of 0.5 C. The average** of the two shows a maximum 0 C and minimum -1.1412 C, giving a maximum variation of 1.14 C.

Of course, had he said 500 years, he would have shown a 3.17 C decline in temperature between 1553 and 1716 (163 years) for Vostok, but still not for GISP2 or the average value.

That is, of course, irrelevant as you know. Both GISP2 and Vostok are regional temperature indices, and regional temperature fluctuations are expected to be much larger than global temperature fluctuations. That is particularly true at the poles, where we expect higher value fluctuations than at the equator. If we expand the number of proxies to just eight, any notion of large scale global temperature fluctuations over a short the centenial scale in the holocene is clearly unwarranted:

Note, the eight temperature series include both Vostok and Gisp2. As this is very well known, the question for NN1953VAN-CA is, why are they excluding data to make plausible a clearly falsified claim?

** Average taken by infilling a value for all dates by persistence within each data series, then taking the mean at each date.

Moderator Response:

[JH] Thank you for the clarification.

NN1953VAN-CA at 14:08 PM on 11 November 2015

Climate's changed before

responding to moderator,

In my comment NN1953VAN-CA @504 I was not being dismissive and I do understand nature around me.
There is no politics in my comment, unless … mentioning that CO2 is taxable??
I was trying to point out proportions in atmosphere content and emphasize proportional influence.
Somehow present content of CO2 concentration in the atmosphere does not produce mathematical models calculated temperature raise. That is point and lacks reasonable explanation.
IPCC prediction quote:
The average predicted temperature increase over the next 100 years is around 3 degrees centigrade
Looking at previous measurements – Antarctic or Greenland Ice core – Global temperature, recently (300 – 400 years ago) varied within 3 degrees in span of 200 years without significant CO2 change.

Moderator Response:

[JH] Please document the sources for the assertions that you have made.

[PS] Yes, your comment on tax was a completely political insertion. And your last sentence would certainly be dismissive hand-waving to me. Furthermore, your comments so far contradict your assertion "I do understand nature around me." For instance the comment "Looking at previous measurements – Antarctic or Greenland Ice core – Global temperature, recently (300 – 400 years ago) varied within 3 degrees in span of 200 years without significant CO2 change." only makes any sense if you somehow believed that science asserts that only CO2 can change the global temperature. It does not (eg see here) as both the above article and the pointers I provided indicate. Furthermore you continue to conflate local temperatures with global. A better way to assess climate sensitivity from glacial cycle (using all forcings), is discussed here (note Fig3)

villabolo at 13:05 PM on 11 November 2015

G R A P H E N E

And what will the Koch brothers do to stop this technology?

chriskoz at 12:57 PM on 11 November 2015

G R A P H E N E

Typo in my previous post: of course Avogardo constant is 6.022E23 atoms per mole

chriskoz at 12:53 PM on 11 November 2015

G R A P H E N E

...one atom (0.35 nm) thick. 1 gram of graphene is sufficient to cover an area of 2,630 square metres and one square metre weighs 0.77 milligrams

2,630 m²/g seems ~right based on the calculation I've done using Avogardo constant (2.022E23 atoms per mole, i.e. 12g in case of C)

But 0.77 mg per m² looks like a mistake. 1000mg over 2,630 m2 reduces to 0.38mg over 1 m². Unless "1 m²" cannot exist in a single layer but for a strange reason, two layers are needed.

Tom Curtis at 11:44 AM on 11 November 2015

Water vapor is the most powerful greenhouse gas

The misnamed "old sage" (@ 222) asserts that raindrops are "... the only generator of radiation of any significance in the atmosphere". That is, he claims the vast majority of radiation in the atmosphere comes, not from water vapour, but from water in a liquid (or, presumably, frozen) state. He provides no source or data for the claim. It is, however, a claim shown easily to be false by clear sky surface, downward IR spectrums such as this one from Wisconsin:

Note that the H2O lines shown are for water vapour, not liquid water which has a different spectral signature, being effectively a black body in the IR spectrum.

The relative contribution of liquid water to atmospheric radiation can be checked by comparing the cloudy and clear sky radiation using a radiation model. Using modtran, with tropical atmosphere, 0 km altitude looking up, but otherwise default settings, the back radiation is 347.91 W/m^2 in the clear sky state, and 418.25 W/m^2 with a low cumulus cloud cover. That is, the low cloud cover increases the backradiation by 70.34 W/m^2 or by 20.2%; but that liquid water contributes >50% of the total radiation where it is present.

It contributes greater than 50% because the other radiation is still emitted, but then absorbed by liquid water drops. Indeed, where present, if we consider all the radiation emitted by liquid water drops and then absorbed by other drops before escaping the cloud layer, the total emission by liquid water, where present is >> 50%, but how much greater would be very difficult to determine (and beyond the capabilities of public access radiation models). It may be this fact that "old sage" is relying on in his claim. If so, it still does not justify the claim as it only applies where the liquid water (ie, clouds) is present.

A full examination of the issue using global cloud cover and allowing for all emissions may justify the claim that liquid water in the atmosphere is responsible for the vast majority of all emissions in the atmosphere - or not. That however, is irrelevant to "old sages" specific claim, however, which was that it was "the only generator of radiation of any significance". As seen above, under some circumstances adding the cloud layer only increases backradiation by 20%, so that emission from liquid water in those circumstances is of significantly less (approx a quarter of) significance than emission by gases (including WV), because it only makes about a 25% difference to the total backradiation.

Even that, however, is overly generous to "old sage". An increase in backradiation makes no net difference to the surface energy balance because it will be balanced by increased evaporation, or increased convection (as we have all seen in the formation of cumulo-nimbus clouds). In contrast, a TOA energy balance is, in the end, only eliminated by a change in surface temperature. Therefore it is the TOA energy balance which determines the effect on GMST of changes in radiative components of the atmosphere. And there we are fairly confident about the relative effects. Specifically, CO2 contributes about 20% of the total greenhouse effect, clouds (liquid and frozen water in the atmosphere) about 25% and WV about 50%.

So, in the end, what "old sage" says may be true if "significance" is interpreted purely in terms of quantity of emission (although he has not shown it). If that is how he intended it, however, it is doubly misleading. Misleading because, by focussing on emission only and ignoring absorption, he grossly overstates the relative impact on daily weather (backradiation); and misleading because by focusing on backradiation he completely ignores the primary factor effecting global climate change.

Tom Curtis at 10:49 AM on 11 November 2015

By rejecting Keystone, President Obama cements his climate legacy

ryland @4, another way of saying there is an increase in transport complexity is to say that the cost of the tar sands oil, delivered to market, will be greater. And if the cost is greater, sales will be less. From that it follows that, on your own assumptions, less tar sands per unit time will be consumed, because of the pipeline ban. As other, renewable energy sources become cheaper and more available, that in turn means that less tar sand oils will be consumed overall. So, from your own assumptions, it is clear that your first claim is mistaken.

Apart from that consideration, in moral issues (and the bringing of new sources of CO2 emissions to market is definitely a moral issue in todays world), that the immoral act will be done anyway by some other never excuses doing it yourself. The appeal that the tar sands oil will be transported by some other means is just the naked claim that moral considerations should be excluded from economic considerations. It do not subscribe to that sociopathy.

Dcrickett at 07:52 AM on 11 November 2015

G R A P H E N E

When I was in college, a common saying was that it was not too urgent to quit smoking, because science was about ready to bring us "safe" cigarettes. And when I was in high school, Lewis Strauss, Chairman of the Atomic Energy Commission, promised us "electricity too cheap to meter." And we hear about the limitless inexpensive energy we'll get from fusion power.

"Graphene Power" might well be the answer to the billion+ maidens' prayers. But time scales for implementation? I fear that under the best of lucky-but-reality-based dreams, we gotta quit smoking, diet, exercise, drink more water and less alcohol... and walk/bike/bus, wear long underwear in season, etc.

John Hartz at 07:52 AM on 11 November 2015

Water vapor is the most powerful greenhouse gas

In a press release issued yesterday (Nov 9, 2015), the World Meterological Organization (WMO) states:

Water vapour and CO2 are the two major greenhouse gases. But it is CO2 which is the main driver of climate change. Water vapour changes are the so-called feedback mechanisms and happen as a response to the change in CO2. For a scenario considering doubling of is CO2 concentration from pre-industrial conditions, i.e. from about 280 to 560 ppm, water vapour and clouds globally would lead to an increase in atmopsheric warming that is about three times that of long-lived greenhouse gases, according to the Bulletin*.

Greenhouse Gas Concentrations Hit Yet Another Record, WMO Press Release, Nov 9, 2015

*WMO Greenhouse Gas Bulletin issued Nov 9, 2015.

KR at 06:49 AM on 11 November 2015

Water vapor is the most powerful greenhouse gas

old sage - Um, no. The only phrase in your comment that is correct is that "..as it warms, more water vapor is produced". Not even a complete sentence.

Water vapor acts as a feedback to CO2 driven temperature changes, and while it radiates a significant portion of climate energy to space, it's strictly through thermal emission from water vapor - not collecting energy from molecules 'dissolved in water droplets', which is complete, utter, nonsense. Nor by any means is it the only pathway to Earth emissions - CO₂, CH₄, CFCs, clouds, the atmospheric window, etc, all share in IR emissions.

The limiting factor in climate feedback is the Stephen-Boltzmann law, wherein energy radiated to space scales with total Earth emissivity and T⁴ temperatures.

I strongly suggest, 'old sage', that you do some reading before posting additional misunderstandings - The Discovery of Global Warming by Spencer Weart is an excellent and approachable place to start.

ryland at 06:46 AM on 11 November 2015

By rejecting Keystone, President Obama cements his climate legacy

Tar sands oil will still be extracted, transported and consumed whether the pipeline is there or not. Can't quite see how this pipeline ban will affect this except to increase transport complexity.

old sage at 05:57 AM on 11 November 2015

Water vapor is the most powerful greenhouse gas

There seems to be an obsession with positive feedback here. Earth's stability arises from the fact that as it warms, more water vapour is produced. That then rises and condenses out into water droplets. These collect translational energy from all the molecules which dissolve in them - h2o, co2, n2,o2, converting it to vibrational together with latent heat of condensation. The raindrops - being the only generator of radiation of any significance in the atmosphere - then get on with the job of pushing more energy out, the higher they are and the more complete the cloud cover the greater the portion leaving earth. It is radiation from clouds which keeps the temperature up under a cloudy sky. It's radiartion from clouds which keeps earth warmer under cloudy skies, not radiation from water vapour.

Moderator Response:

[PS] Attempted to fix html.

Can I please suggest that before you criticize the science, that you take some time to first understand it. There are good resources on this site to do so. Repeatedly making nonsense assertions will be regarded as sloganeering.

Ed Wiebe at 03:41 AM on 11 November 2015

G R A P H E N E

According to the paper about the discovery of superconducting lithium decorated monolayer graphene, it is superconducting at 5.9 K.

http://arxiv.org/abs/1508.05925

Moderator Response:

[PS] Fixed Link, html.

wili at 02:40 AM on 11 November 2015

G R A P H E N E

"Graphene does not occur naturally"

Does that mean it can't be broken down by natural processes? Don't we already have problems with pollution from nano-tubes etc. Is this going to add to that problem?

kar at 02:38 AM on 11 November 2015

Lessons from Past Climate Predictions: Wallace Broecker

Please check if you could update the correct URL for the "missing link" to the paper, in the first sentence:

... to predict future global temperature changes. His 1975 paper Climatic Change: Are We on the Brink of a Pronounced Global Warming? is widely credited with coining the term "global warming". ...

Moderator Response:

[PS] Thanks for that heads up. In meantime try this link.

wili at 02:28 AM on 11 November 2015

G R A P H E N E

"The only way to curb production of fossil fuels and ultimately end their use is to replace them with an affordable, reliable alternative."

Certainly, this is an important element in moving away from ffs. But we also need to increase efficiency and decrease total use. As Kevin Anderson has pointed out, these can be done much more quickly and radically than a build out of a whole new energy generation system. And time is one thing we don't really have enough of!

www.youtube.com/watch?feature=player_embedded&v=KumLH9kOpOI

CBDunkerson at 23:45 PM on 10 November 2015

Tracking the 2C Limit - September 2015

For future updates you may want to express the total warming as a range, or at least talk more about how the baseline impacts the result. I'm seeing more news articles mention a total warming figure, and most seem to be using a higher baseline figure.

The media will likely make a big deal when we 'pass 1 C' warming... based on whatever standard they are using. While the 1880-1909 baseline is certainly logical, you might want to try to get an idea of where the media is getting their results and what standard those sources are using. I'm wondering if it isn't just the single year 1880 value.

Tom Curtis at 16:17 PM on 10 November 2015

Climate's changed before

NN1953VAN-CA @504, water vapour is mentioned all the time in discussing climate, as the water vapour feedback. That is because, if you suddenly doubled the amount of water vapour in the atmosphere what would happen is that over a few weeks at most, the excess water vapour would precipitate out resulting in a WV concentration similar to current values. Likewise, if you suddenly halved the WV in the atmosphere, over a few weeks at most the WV would be replenished by evaporation. The upshot is that the only effective means to change the WV concentration of the atmosphere over the long term is to change the temperature.

In contrast CO2 concentrations are far more amenable to alteration over the short term. Indeed, for periods of time less than a few hundred years, changes in CO2 concentration are an almost direct function of emissions. Consequently, be emitting CO2 we have a small effect on temperture which is reinforced by the effect of that temperature change on the water vapour concentration. Doing the reverse, however, would not work.

Finally, as an aside, concentration alone is not a good way to judge the relative effect on the total greenhouse effect of a gas. CO2 may only have one fiftieth of the concentration of WV in the atmosphere, but it has 25% of the effect on the total greenhouse effect.

Moderator Response:

[PS] Any further discussion of water vapour should go to "Water vapour is the most powerful GHG".

NN1953VAN-CA at 15:46 PM on 10 November 2015

Climate's changed before

Thank you, CO2 significance in GW
With CO2 measurements of almost 400 ppm, the recent global temperature measurements somehow do not reflect publicity given to CO2. I am trying to understand how something that is measured in ppm can make such a significant change in global temperature. At the same time, water vapor, which is present in thousand time higher concentration, is not being mentioned at all. There are dry areas on earth, trade winds carrying enormus quantity of water vapor, global circulation, ocean currents (gulf stream) all more influential than CO2 but CO2 somehow has the publicity.

Maybe this is because it can be taxed, or maybe because we can't influence any other factor. Regardless, trying to prove that in the present atmosphere the CO2 at 400 ppm influences the GW and WV at 40% is not mentioned at all, somehow does not work. Our planet has a stable pattern in climate changes for millions of years with CO2 either higher or lower than now; many spices appeared and disappeared, what one has to consider natural, as if not, we as recent planet product wouldn't even come to existence.

Moderator Response:

[PS] Please check your politics at the door and stick to science. Your comment about water vapour are pure sloganeering - the role of water vapour is in an integral part of science. Take the time to read what the IPCC WG1 actually says before trying to be dismissive. Just because you dont understand something doesnt mean that science doesnt either.

Tristan at 15:31 PM on 10 November 2015

2015 SkS Weekly Digest #44

Has this been toon of the week before? It's awesome.

chriskoz at 13:04 PM on 10 November 2015

By rejecting Keystone, President Obama cements his climate legacy

Obama's he climate policy legacy may be overstated by this article.

Most of his policies, including XL rejection and fracking industry expansion, can be attributed to his desire to free US dependence on foreign fossil fuels rather to care about environment.

Perhaps his car and power plant regulations and talks with China are driven by env concerns but this XL may be not.

wili at 13:02 PM on 10 November 2015

By rejecting Keystone, President Obama cements his climate legacy

"When we look back, the Obama Administration will be acknowledged as the first Administration to take climate change seriously"

If true, how sad, given that the Clinton Administration include Al Gore as VP. But I'm not sure one decision out weighs years of 'all of the above' policies that saw big increases in domestic oil drilling, huge increases in fracking, and continued mining of coal, much of which was sent oversees to be burnt. And of course, TransCanada may well try again with the next administration.

John Hartz at 05:11 AM on 10 November 2015

By rejecting Keystone, President Obama cements his climate legacy

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