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Where is global warming going?
suibhne, did you read my reply on G&T on the "Is CO2 a pollutant?" thread? You did not respond there. I took the time to read their article thoroughly, which was... rather painful. G&T display an appalling lack of understanding of the physics of thermodynamics, particularly radiative equilibrium - a concept dating to 1791, well understood and acknowledged as a scientific consensus. The core of their paper uses a strawman argument conflating convection blocking greenhouse effects with radiative greenhouse effects (not true, demonstrable in any freshman thermodynamics class), and from that stating that since they are not the same thing, radiative greenhousing doesn't exist. That's a pure logical fallacy. They make (by my estimate) ~2 errors, logical fallacies, or outright physics howlers (I'll refrain from labeling them lies, but it's hard to understand how such basics are misunderstood) per page. I'll enjoy further comments from people with better physics skills than mine, but IMO G&T isn't worth the paper it's written upon. I put some references to radiative equilibrium in my previous post (linked above) - I would strongly recommend them, as they're important elements of what we disagreed upon in the CO2 thread. -
Flowers blooming earlier now than any time in last 250 years
An article on Washington DC seasonal creep is described in Abu-asab et al, where they studied 100 species; 89 bloomed earlier over the recorded period (1970-1999), 11 bloomed later, with cherries blossoming 6 and 7 days earlier in '99 than in '70. They also provide precipitation data, with no significant correlation found between precipitation trends and first-flowering dates. They do point out that increasing CO2 levels might have an effect, and do not have an explanation for the 11 species that bloom later - but the earlier bloom dates correlate closely with the temperature changes. -
Chris G at 01:36 AM on 29 April 2010A visual depiction of how much ice Greenland is losing
#39 gallopingcamel, "For the last 2,000 years sea levels have been rising by less than 0.3 meters/century. " Yes, substantially less than 0.3 m/century. Over the last 2,000 years, up until recently, there has been negligible change. Over 20 centuries, anything close to that rate would have caused approximately 6 meters of rise. That hasn't happened. Here is a summary http://commons.wikimedia.org/wiki/File:Holocene_Sea_Level.png -
JulianRGP at 01:09 AM on 29 April 2010Skeptical Science Housekeeping: flags, printable versions, icons and links... lots of links
The "Post a Comment" box does not appear for the most recent post which is "Why are there fewer weather stations and what's the effect?" I'm logged in OK and obviously the Post a Comment box appears in this article otherwise I would unable to post this comment! Can someone check/fix it? Thanks!!Response: Now fixed. The last comment had some dodgy HTML. -
Chris G at 00:36 AM on 29 April 2010A visual depiction of how much ice Greenland is losing
@#34, I really like the river and lake comparisons. The cubic volume that John has in nice, but the numbers are too large to get a good feel for. However, I think your math is a little off. I get Mississippi 12,743 m^3/s = 0.000012743 km^3/s *60 // minute *60 // hour *24 // day *365.25 // year = 402 km^3/year // 1 Gton ~= km^3 water, neglecting temperature and sediments Flow rate from http://en.wikipedia.org/wiki/Mississippi_River, which is derived from USGS measurements. So, to keep things simple, the net loss of water (ice flow + melt) off of Greenland is about 3/4 of the Mississippi river at present. If the two measurements above are directly comparable, that means that the flow increased from 1/3 of a Mississippi to 3/4 in a 6 year span. Wow. -
Paul D at 00:14 AM on 29 April 2010A visual depiction of how much ice Greenland is losing
Gallopingcamel said: "Your "rate" argument is nonsense. At the end of the last Ice Age, sea levels rose at an average rate of more than 1.2 meters/century. About 7,000 years ago the rates started to fall. For the last 2,000 years sea levels have been rising by less than 0.3 meters/century. There is no big mystery about this. The main continental ice sheets melted long ago and all we have left is the Antarctic, Greenland and relatively few glaciers." OK by your own figures and checking some others seas rose about 110 metres between the last ice age and 7000 years ago. Not surprising. Humankind was mobile and used to a harsh life, plus the human population was tiny by comparison with today. No major static cities or other developments. eg. Sea levels rising 1.2 metres per century wasn't a big deal for the population at the time, especially if populations had to deal withj much more severe problems. However Now is not the past. Most populations today live in static locations and invest a lot of time and effort building infrastructures that they expect to be preserved for many centuries. Hence the consequences of the remaining ice melting is huge and you are underestimating the impacts. -
Paul D at 00:02 AM on 29 April 2010A visual depiction of how much ice Greenland is losing
Re: @45. There are a lot of reasons why land falls below or rises above sea levels over time. Most of which are red herrings when viewing the global perspective of what is going on. Some parts of the UK are now land locked where as in the past they were on the coast, other parts are underwater where as in the past they were above sea level. The reasons for changes are numerous, but it doesn't impact on the global picture of what is going on. More often than not they are simple diversions. -
gallopingcamel at 23:50 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
Jeff Freymueller (#41), While I generally agree with what you say, it is worth noting that the remains of stone buildings have been found "beneath the waves" in many places, for example in the Mediterranean and Black seas. The submersion in some cases may have been caused by rising sea levels rather than seismic activity. The folks on this blog generally seem to believe that mankind can influence the rate of rise of sea levels. At the risk of upsetting some of you I consider that idea to be nonsense with no credible scientific basis. The sea levels are going to do whatever Mother Nature wants them to do and we need to stop whining about it. -
Ken Lambert at 23:23 PM on 28 April 2010Tracking the energy from global warming
kdkd #83 No it is not clear now. The starting point of John Cooks blog is the OHC graph and discussion of the 'missing heat' over the last 5-6 years. Your argument is that this whole discussion is worthless without longer timescales (up to 30 years) and more annual data. If you can't draw strong conclusions against climate change based on warming from CO2GHG from *this* data, then neither can you draw strong conclusions *for* it. -
kdkd at 22:58 PM on 28 April 2010Tracking the energy from global warming
Ken #82 Nobody is trying to dispute the first law of thermodynamics. However, it seems to be logically invalid to try to draw strong conclusions from the small amount of TOA/OHC data available. This is because the TOA/OHC data is only available for a small number of annual cycles, it represents measurements from a large, complex (and chaotic) system with an estimated measurement error or around 30%. So until either more data is available, and if possible the measurement error is reduced, it is not possible to reach strong conclusions about anthropogenic global warming from the OHC/TOA data. Is that clear now? -
nautilus_mr at 22:22 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
Now..is this it? Kundzewicz paper If it is the paper to which you refer, I would be cautious about citing a slide show intended to accompany a lecture, without knowing how the speaker intended to use the information. In any case, the graphic on page 7 shows temperature, not the rate of temperature change (temperature anomaly). Naturally, we expect absolute temperatures to be higher in urban areas. Temperature anomaly measures the underlying trend in temperature, irrespective of the urban heat island effect. If urban power use were a significant climate forcing, the trend would differ from region to region, but it is precisely this trend that turns out to be quite homogeneous around the world. It actually doesn't even matter whether the density of stations varies from continent to continent, because the global trend is indicated quite uniformly. This can only be explained by a well mixed, general effect in the atmosphere - urban power consumption is not such a generalised effect, but CO2, which disperses very widely, is clearly the best explanation for the evidence. -
Ken Lambert at 22:21 PM on 28 April 2010Tracking the energy from global warming
Chris #80 Forcings in W/sq.m are both positive and negative energy fluxes (power) which when summed; produce a theorized imbalance. If you integrate the forcing 'imbalance' WRT time you get the total energy over that time period added to or subtracted from the earth - atmosphere - ocean system. First law of thermodynamics says that this energy (Joules) must show up somewhere in the system either by warmer or cooler land, atmosphere, water; or phase changes into ice, melting ice and evaporation or condensation of water. This is not 'numerology'; it is long established scientific fact. If we see flattening of temperatures over the last 5-6 years or more, then less energy is being added to the system or due to thermal lags, this reduction has already happened some tme ago. Tell us Chris how long these lags (response times) are? If you look at your sea level graph, the Topex data follow the 3.2mm/year slope until 2002, and the Jason data follow a lesser constant slope from 2002-10 or if you stop linearizing a non-linear system - a curve fit would show pronounced flattening from 2005 onward. This is real evidence that sea level rise has slowed or flattened, and being such a giant reservoir of heat energy, indicates a reduced or non-existent uptake of heat. When the observation goes against the theory of increase forcing imbalance and greater energy uptake, have a hard look at the theory as well as trying to bolster the observation with better data. -
nautilus_mr at 22:01 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
re # 8, Would you kindly provide a link to the Kundzewicz paper please? -
Arkadiusz Semczyszak at 21:21 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
re#7: Just compare the map on page 7, "Climate change and extreme events - the Central European perspective," Z. Kundzewicz (IPCC expert - COP 14, 2008) the population density of Europe; to accept - at least the possibility of existence - the European UHI (covering and villages) . The same is true in SE China, Japan, and other. Only in the U.S. there is a sufficient number of truly rural stations. Among other things, hence the temperature change in the U.S. differ greatly from those in Europe and worldwide. -
neilrieck at 20:58 PM on 28 April 2010The significance of past climate change
Good presentation but here is a much more straight-forward method when presenting to non-scientists. <<< Point #1 >>> The primary mover of Earth's overall climate is Milankovitch Cycles (the main one being changes in the orbital shape from circular to elliptical then back). http://en.wikipedia.org/wiki/Milankovitch_cycles When the orbit is circular like now, we experience interglacial periods which average 20,000 years in length. When elliptical, we experience glacial periods which average 100,000 years in length. This is verified by ice cores from Greenland (Century Station), Antarctica (Vostok Station), as well as deep sea cores from the Indian Ocean (Vema 28-238). <<< Point #2 >>> Effects from volcanoes, thermohaline circulation, atmospheric currents, storms systems, and feedbacks from greenhouse gases add or subtract from the Milankovitch cycles. <<< Point #3 >>> During the previous interglacials, warming always occurred first which then triggered the release of dissolved CO2 from the oceans. This caused the release of other greenhouse gases like methane and water vapor (to only name two) which the forces Earth's climate hotter. In our current interglacial which started 11,700 years ago, industrial humans released CO2 ahead of the main warming trend. So a run-away warming effect could be right around the corner. reference (see the second graphic): http://www.southwestclimatechange.org/climate/global/past-present <<< Point #4 >>> Heat doesn't always immediately increase temperature. By definition: one calorie of heat will raise the temperature of one cc of water by one degree Celsius. However 80 calories of heat are required to convert one cc of zero degree ice into zero degree water. Question: what happens when all the ice is melted? Answer: heat will begin to raise water temperature. http://en.wikipedia.org/wiki/Enthalpy_of_fusion 70% of the Earth's surface is water. When it is heated, atmospheric and ocean currents move this excess energy toward the poles. So why is the arctic melting much faster than the antarctic? Answer: The Arctic is mostly an ice structure at sea level where it is exposed to oceanic heat. The Antarctic is an ice covering over a continent with an average elevation of 2300 m (which is the largest of all contents). As everyone already knows, higher elevation means cooler temperature. But higher elevation also means less exposure to warm oceanic water. Most people already know that ice reflects 90% of incoming sunlight while water absorbs 90%. This albedo change (hysteresis) is another snap-action feedback. <<< Optional-Speculative Point 5 >>> Has Earth always been effected by glaciations this way? Scientists don't think so. Major changes to Earth's climate occurred after geological forces formed the Panama land bridge 3 million years ago (joining North America to South America). This blocked east-west ocean currents between the Pacific and Atlantic. Many believe that this triggered changes in Atlantic currents which caused warmer temperatures to be delivered to Europe. (London England is warmer than Labrador while Glasgow is warmer than Moscow). Since it now seems that ocean currents are more important than previously thought, we now need to wonder what will happen if climate change disrupts the thermohaline current or even the gulf stream. If this happened, global warming could actually cool Europe while melting Russia's Arctic (I'm sure Russians would think this a benefit) -
nautilus_mr at 20:42 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
re#4: Is this the de Laat article to which you refer? (pdf version here- http://www.knmi.nl/~laatdej/EOS2008.pdf) I have to say it makes a pretty underwhelming argument, consisting of little more than innuendo. It makes no predictions in order to engage with data - but there are obvious predictions it should make: namely that if human energy consumption is a significant forcing of global temperature, we should observe the rate of warming to vary dramatically by region. As we all know -and as is spelled out elsewhere on this site, for example- the rate of warming is remarkably consistent across the globe. -
sleepership at 20:18 PM on 28 April 2010Flowers blooming earlier now than any time in last 250 years
Actually last winter we where a Zone 7- lowest temperature was 1 degrees in my north central/eastern Connecticut location. Boston & Providence where a few degrees warmer (Bostons low was actually 10 degrees-making it a borderline zone 8- and Providence at 6 degrees making it a solid zone 7. -
HumanityRules at 19:25 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
John can you just clarify a few points. 1) Have the "dropped stations" stopped recording temperature or have they been dropped from the set of stations that go into the GHCN series? 2) Has the data from the "dropped stations" that was collected before they were dropped been dropped from the GHCN series? Just from the 3 graphs you show the looks to be good correlation from 1950's onwards but earlier decades look very different. Any thoughts why? -
JMurphy at 19:19 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
I'm still amazed that there are people out there who will cite Watts as a source for anything but humour and laughter. His beliefs about the Darwin station have been dismissed and disregarded by all but those most in denial. Just by reading one blog (The Way Things Break) I was able to get access to two official sources (BOM, Australia & NOAA) which show why Watts is mistaken - as usual. It even led to a pertinent REALCLIMATE comment which summed up the situation very nicely : "Second, just because the writer can't work out why something changed, it does not mean it was 'manually adjusted'". As for UHI, you should read more of the articles on SKEPTICAL SCIENCE, especially here and here -
Mike_Allen at 19:18 PM on 28 April 2010Has Arctic sea ice returned to normal?
I have a question about sea ice formation. How does salinity effect the sea ice. How much salt remains in the sea ice, does the layer below the ice become more saline? Does this affect the temperature of ice formation? What about acidification and ice? I can't test this in my freezer it just won't do -20C. I'm thinking about optimal conditions for sea ice growth. -
Arkadiusz Semczyszak at 18:24 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
There is no sufficient argument to deny the existence of the current warming relying on data from rural stations, but ... ... the scale of the current warming is questionable. For example, data from rural stations in Europe may not be reliable. All Europe Central and Western Europe is (in all likelihood) a great sub-continental UHI (de Laat, ATJ, 2008: Current Climate Impact of Heating from Energy Usage). There is also the problem of homogenization of data from different time periods. Anthony Watts wrote about it (for example: the Darwin station in Australia). -
Chad at 17:50 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
johnd, Calculating a global average of temperature as opposed to temperature anomaly would seriously bias the analysis. For example, losing spatial coverage at high northern latitudes would cause the global average to spike when it shouldn't. By converting the station data to anomalies the fact that the tropics is much warmer than higher latitudes and that stations are being lost in those colder regions becomes much less a serious concern. The difference in anomalies is much smaller than the difference in temperatures between those two regions so the potential for bias is much lower. Like John Cook pointed out, losing stations at high latitudes (which have experienced the largest warming) will depress the warming trend a bit. -
A visual depiction of how much ice Greenland is losing
#39 gallopingcamel, You mention plants growing from pole to pole, but never explain exactly how long you think this would take. I assure you new ecosystems do not sprout up overnight. In the meantime, our society could be going through some severe economic and environmental turmoil. It is of little comfort to say that 2000 years from now our problems may not seem so bad. It's also interesting you noted potential agriculture improvements in Canada and Siberia, but neglected to mention any other possible effects. There are other places in the world after all. How would lower latitude countries be affected? Did you weigh the negative effects vs. the positive to come up with your conclusion that warming will be a "blessing", or did you just cherry pick the details that support your conclusions? That's an intellectually lazy approach, and you'll need to do better if you want to make a convincing argument. If you are interested in knowing more about the predicted effects of global warming, both positive and negative, this post is a great start. The IPCC and EPA also go into more detail on the subject. -
johnd at 17:24 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
Is there any chance of getting graphs that compare the calculated temperatures rather than comparing the anomalies? Only then can we be sure that there is no basic bias. -
qball17 at 16:08 PM on 28 April 2010CO2 effect is saturated
so the atmosphere is infinitely large is it? so what is the better model? can you show me some solid evidence that debunks the saturated greenhouse effect and proves that CO2 drives climate? -
robert way at 16:06 PM on 28 April 2010Why are there fewer weather stations and what's the effect?
I know that in my region the GHCN has dropped some stations which still operate. The stations take only daily recordings and have them online in the climate.gc archive for all of canada. Turns out GHCN only downloads the monthly data which results in leaving out a lot of available data. In a related story, the two stations I looked at in particular that they dropped are rural stations which have undergone incredible warming in the last two decades (2-3 degrees) -
robert way at 15:58 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
Chris G, I wouldn't call it a nitpick at all. This individual spent so much time on skeptic blogs looking up his argument that he forgot that you need the overall knowledge of the issue at hand also. It is not as though we were referring to some abstract type of specialist. Glaciologists are very well known today and not taking the time to learn who it is that studies these things, and then talking in a manner as if he/she were an expert is not something which I am willing to defend. You look up the core literature and gain the core knowledge before you make accusations about the existence of AGW or not. I don't want to be rude to the individual in any shape or form but it does get a little annoying when comments are made with such certainty and yet such ignorance all at once. -
scaddenp at 13:43 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
The "rate" question relates to the ability of our society to cope with change. Past rates are of no relevance but some projections exceed 1.2m/century. While there is less ice to melt now, the rate of temperature is higher, much much higher. Ice leaves behind outwash and rock, not past soils. Plant colonisation is rapid but a productive soil, especially compared to delta, very slow. -
Jeff Freymueller at 13:30 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
#39 gallopingcamel, I would point out that there were no advanced human civilizations at the end of the last Ice Age, so the rapid sea level rise (and radical changes in river flow near the coastline) did not threaten any fixed human assets. In fact, I might remind you that the rise of the first agricultural civilizations began only AFTER the rapid sea level rise stopped, and in fact it began in several places around the world shortly after the time that sea level stabilized (6000-8000 years ago). Which is a relatively long way of saying that your point about sea level rise having been faster then is totally irrelevant to the present day. -
Jeff Freymueller at 13:23 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
The Mississippi and Lake Erie comparisons are interesting. But still hard to visualize unless you have seen them. What about the discharge of all the world's rivers? That might be an informative comparison. One of my students expressed ice volume volume loss in terms of Nimitz-class aircraft carriers, reasoning that these were probably the largest mobile things built by man. But that still resulted in a huge number -- who can visualize 10,000 Nimitz-class aircraft carriers? (that number was not for Greenland). -
gallopingcamel at 13:09 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
scaddenp (#37), Your "rate" argument is nonsense. At the end of the last Ice Age, sea levels rose at an average rate of more than 1.2 meters/century. About 7,000 years ago the rates started to fall. For the last 2,000 years sea levels have been rising by less than 0.3 meters/century. There is no big mystery about this. The main continental ice sheets melted long ago and all we have left is the Antarctic, Greenland and relatively few glaciers. Your "soil creation" argument is not much better. For much of Earth's history there were no ice caps so plants were growing from pole to pole. Once the ice melts, plants will start growing again, except in those places that have been stripped down to the bed rock by glacial flow. -
scaddenp at 12:53 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
And while we are at it, in terms of straight productive farmland, how do you think polar islands and mountain basins compare to river deltas? -
scaddenp at 12:15 PM on 28 April 2010A visual depiction of how much ice Greenland is losing
How many more times gallopingcamel do I have say "rate" to you? Melting glaciers might be fine if they do so slowly enough for us to adapt to the rising sealevels. And areas left by glacial retreat do not instantly turn into productive farmland -soil creation takes time. Also, if rates of sealevel rise were set to remain at around 3mm/yr then it wouldnt be too bad, but they are not. -
gallopingcamel at 11:33 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
e (#30), "Unfortunately temperatures are continuing to rise, so not only will the melting continue, it will get worse." It is strange that reasonable people can draw entirely different conclusions from the same data. Temperatures have risen by ~0.7 degrees Celsius since 1850 and I would describe that as "fortunate" given the miserable conditions during the "Little Ice Age". During the LIA glaciers were swallowing up Swiss farms. With a little more warming large areas of Canada and Russia would become farm land. Overall, the melting of glaciers is a blessing, not a curse. -
Rob Honeycutt at 10:05 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
@notcynical... I think it would be hard to relate to the volume of lake Erie. Mississippi river is better but I think people don't have a clear relationship to that either. Volume might be better represented by something more common like the Superdome or some other stadium. Some large common object or space that represents volume. I also think that CBDunkerson's comments on the linear growth aspect of ice sheet loss is very important. It's probably valid to mention that the trend is likely accelerating without attaching a particular rate to it. And even Berényi Péter's comment of relating it to the total volume of the Greenland ice sheet is important. I think this gets right down to the nitty-gritty of why a) so many people are reacting negatively to the idea of AGW, and b) why it's been so easy for the climate change denier crowd to make hay out of the issue. Regular non-scientific folk lack adequate ways to understand the scale and meaning of climate change. What John's trying to do, along with all the great suggestions here, is totally on the right track to fix that. -
notcynical at 06:41 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
For what is is worth, the Empire State Building in the graphic was not informative for me. If I'm comparing the height of the E.S.B. to something, I'd use other buildings, towers, etc. If we are comparing annual ice loss to something, other water volumes seem more appropriate. Previous suggestions about the entire ice sheet and the amount of sea level rise are informative, even if less dramatic. Two comparisons I found interesting are to the annual discharge of the Mississippi River: about 0.4 km**3/year and the volume of Lake Erie: 480 km**3 (both from Wikipedia with unit conversion). If my arithmetic is correct(and I know I'll hear about it if I'm not) every year Greenland is adding the equivalent of 60% of Lake Erie into the world oceans, or the equivalent discharge of 715 Mississippis. That might be a challenge to put into a graphic. -
mspelto at 05:41 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
#30 and #32 whether you look at the Alps, Sweden, North Cascades etc. there were significant advances in the 1950-1980 period. The glaciers have since entered a very pronounced and significant retreat that has led to the loss of a number of glaciers. This is not merely an ongoing retreat since the Little Ice Age note three of hundreds of examples that could be givenMer de Glace or Brady Glacier orGigjokull before the eruption. True there are many that have been retreat ever since the LIA, but it is not the majority in most alpine ranges. -
Kiwiiano at 05:14 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
And don't forget that the need for mass evacuations and the loss of many ancient and treasured cities & their infrastructure will be against a background of rapidly depleting resources and the end of cheap energy. -
aj1983 at 04:28 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
@Alexandre: Yeah, but not if you are living near or below sea level in the Netherlands (or several other places), then every meter becomes very much inconvenient. Our species is not very much at risk, but our modern society is much more vulnerable. BTW, at many places glaciers have been melting since the little ice age, I think you can find many examples in the NH. However, the rate of melting seems to be accelerating, which is a bit worrying. How large the impact of natural variability is compared to AGW we will probably see in the next few decades, because of the quiet sun and negative PDO (which have both been proposed by the skeptics for giving large global temperature variations). -
A visual depiction of how much ice Greenland is losing
gallopingcamel @#25 and nofreewind @#3, Even if there was glacier retreat in 1900, it would be consistent with the steady increase in global temperatures at that time. CO2 does not cause glaciers to retreat, CO2 causes warming which causes glaciers to retreat. Unlike the warming that began around 1970, the warming from about 1850 to 1940 was primarily due to an increase in solar activity. This is discussed some here. It is also worth pointing out that the warming now is already more extreme than the 1850 warming period, and projected to get worse. To the other question, even if temperatures were stabilized today glacier retreat would continue for a long while, there is nothing inconsistent about this. This was already pointed out in John's original post: "It takes time for the massive Greenland ice sheet to respond to warming." The glacier retreat you see today is the result of warming in years past. Unfortunately temperatures are continuing to rise, so not only will the melting continue, it will get worse. -
Rob Honeycutt at 03:11 AM on 28 April 2010Has Arctic sea ice returned to normal?
@CBDunkerson... Thanks for that response. I guess I'm also curious about the relative importance of summer and winter extent. Winter ice extent is, I'm assuming, a nominal feedback and mostly an annual data point, whereas summer ice is going to be a more important data point because it's going to suggest more about ice volume and positive feedback due to the albedo of the open ocean. -
Rob Honeycutt at 02:54 AM on 28 April 2010Has Arctic sea ice returned to normal?
@nofreewind... I'm not sure you can call two positive upticks a recovery in the face of 30 years of negative trend. If that positive trend continued for the next 5 years we might have something to begin talk about. But I don't think this answers my question. I'm actually asking less about the disingenuousness of WUWT and more about the lack of negative feedback because winter ice extent occurs mostly during the 24 hr darkness of winter. I'm not suggesting that the winter ice extent isn't important - it's a relevant data point - but with regards to climate change winter ice extent is going to offer very little of what one might hope for: Increased albedo and some negative feedback. (FWIW - We should ALL be hoping that there are more negative feedbacks out there than science seems to be currently finding.) -
Alexandre at 02:48 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
It´s only a small fraction of Greenland´s ice each year. It´s only a tiny increase in CO2 concentration each year. And hey, a few meters of sea level rise are pretty insignificant compared to the total ocean depth. Rationalization is the ultimate solution to global warming. -
Riccardo at 02:29 AM on 28 April 2010Tracking the energy from global warming
Just one more tiny bit of informations. A huge current originating in Antarctica and flowing northward in the Indian Ocean below 3000 meters has recently been discovered. It's volume transport is around 30 Sv. For those of you not familiar with this unit of measure (Sverdrup), 30 Sv are about 20% of the maximum transport of the Gulf Stream (which so nicely helps warming north-western Europe :)). There's much more in the deep ocean than we'd like to admit.Response: Thanks for the link to the Nature article, that's a fascinating development. Considering the Southern Ocean is warming faster than the global trend, I wonder if this is a possible mechanism for transporting extra heat to the deep ocean. I noticed a comment posted repeating the common error of confusing sea ice with land ice and posted a follow-up comment.
So one Sverdrup is equivalent to 30 million cubic metres per second. Hmm, I wonder how big that much water would compare to the Empire State Building... -
Chris G at 02:08 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
#16 Arkadiusz, "By this work in the years circa 193X-5X in Greenland was warmer than today " I understood the work to say that the slope of the 'line' (line segment?) was steeper then than more recently. That doesn't say anything about the height of the line, and temperature is X. Regarding #3 NoFreeWind, #8 rway024, #22 CBDunkerson #23 The Ville, #25 gallopingcamel, @#25, It's hard to know how to answer questions that imply what you believe to be a false premise. (Have you stopped beating your wife?) If you are going to answer at all, the first step has to be pointing out that the premise is false. Once the premise has been shown to be false, there's really no need to answer the original question. (#3, #8, #25) @#23, "Prior to about 1999 Greenland's ice sheet was pretty much in mass balance." (#22) is at least in part a response to "Greenland has been warming and loosing ice for well over 150 years" (#3) @#8, 'glaciologist not a "glacierologist" ' is a bit of a nit-pick. You're correct of course, but Camel is right, there's no need to make a point of it. Lastly, and to further address one point from #3, "Temperatures didn't seem to rise but glaciers did melt." It might be useful to remember that, in proximity of a phase state change, temperature looses its tight coupling with energy. The temperature in a glass of ice water will not change significantly between when it is mostly ice to when it is mostly water, but there is a lot of energy change. But then also, melting isn't the only way for a glacier to retreat. -
chris at 01:39 AM on 28 April 2010Tracking the energy from global warming
Ken Lambert at 00:15 AM on 28 April, 2010 That's not really right Ken. As kdkd says, measurement errors over very short periods of observations/data collection can easily confound interpretations. One needs to be confident of the measurements before making significant interpretations. That's a basic tenet of science. There's not much point in running free with calculations and various forms of numerology, unless one is fairly certain of the data; without that your interpretations are really only "theories" or hypotheses". That confidence (that the data is a true measure of the phenomenon under investigation) comes from (a) analysis of trends over sufficiently long periods that measurement and stochastic variations average to small values, and (b) having sets of self-consistent independent data (e.g. sea level rise and its mass and steric contributions; ocean heat measures; radiative imbalance etc.). So for example although the rate of sea level rise was apparently a bit slower for a couple of years, it's still smack on the 3.2 mm line now (see updated data in my post above), and there isn't really any evidence that the rate of sea level rise has slowed down. Your comments about solar and greenhouse forcings aren't quite correct. Remember that one can only interconvert forcings and temperature changes under equilibrium conditions. Otherwise one needs to factor in the various response times of the climate system. So the expectation that the effect of the solar cycle downturn on surface temperature on average temporarily (5/6 years) cancels the temperature rise from the enhanced greenhouse forcing doesn't say anything necessarily about the relative magnitudes of the forcings (solar and enhanced greenhouse). It just means that surface temperatures are rising near 0.15-0.2 oC per decade under the cumulative greenhouse forcing, and that the solar cycle opposes this by around 0.1 oC during the 5/6 years of the solar downturn and supplements this ( by a similar amount on average) during the 5/6 years of the solar upswing. -
Cecilia at 01:11 AM on 28 April 2010Phil Jones says no global warming since 1995
Could I ask what the significance level (confidence level) of 1995-2009 really is? I've read blogs about 92-94%, but is this correct? -
CBDunkerson at 01:04 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
Ville, your general conclusions are valid but there are a few caveats. First, the 'doubling every six years' scenario is extremely unlikely and the only one which would require immediate action. For any other plausible situation we've got some time to work with and thus can afford (on this issue) to give it several more years to see how the trend line is actually developing. Currently we don't know if it going to be decades, centuries, or millennia... in ten years we likely will (though still not exactly how many). Each of those timeframes requires different kinds of planning. Thus, yes we should be planning for long term sea level rise. However, I think we have time to see how that is going to develop to better inform our efforts to handle it. Of course, all of this is just Greenland. Antarctica is melting too... and oceans are also rising from thermal expansion. However, even with all those factors combined we have time to see how trends are going to develop before taking action. -
mspelto at 01:03 AM on 28 April 2010A visual depiction of how much ice Greenland is losing
I like the graphic. I would like it better if the cubes had more of glacier blue and a bit glacier textured. Then again I think glaciers are gorgeous. Two points to note, going back to a conference I attended in 1985 that was looking at the future of Fast Glacier Flow, we presented work on why the Jakboshavns would speed up in a warmer climate and why other glaciers could become more like the Jakobshavn. It turns out the mechanics behind this forecast were essentially correct. It is the number of Greenland glaciers that are responding that is most striking. All of the 34 largest marine terminating outlet glaciers have accelerated, even the thinner, slower, northern outlet glaciers Humboldt and Petermann Glacier are. -
LordLiverpool at 00:32 AM on 28 April 2010Climate's changed before
The mistake on the part of environmentalists has been to talk about "saving the planet". This leads directly to the sceptics' argument that the planet has changed in the past, and done just fine. Quite true. But we're not really interested in the planet, we're interested in our own welfare. A dramatic change in the climate would, first and foremost, affect our civilisation. Our cities, farmland and economies are far more vulnerable than the planet itself, which will no doubt continue to adapt. To win the global warming argument politically, we need to underline the threat to ourselves from climate change, rather than talking about ice sheets, polar bears and barrier reefs (important as those things might be).
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