Arguments
Recent Comments
Prev 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 Next
Comments 124951 to 125000:
-
Marcus at 00:58 AM on 26 January 2010Peer reviewed impacts of global warming
Also, I used to try & debate this stuff at places like The Australian's website, but found the place dominated by denialists who had not a clue about holding a decent debate-& instead resorted to name calling & conspiratorial whispers about "global government" (aka the UN) trying to impose their rules on sovereign nations like Australia. It really just got pathetic, so I gave up! -
Riccardo at 00:49 AM on 26 January 2010Peer reviewed impacts of global warming
Ubique, although i'm no expert, there's the obvious answer to your question: there's no such temperature. What i mean is that you always have parts of the ecosystem that will do better and other that will do worse after any change in temperature. So, how could be such a ideal temperature be defined? Things look different if you look from the point of view of our own specie and its current civilization. Given that its development occurred during a relatively stable climate, there is again an obious answer: no change at all. Of course there's some resilience up to a certain level of change, but it has an overall cost. We need to balance the two, some inevitable warming and the costs of limiting it; the former is the science of climate, the latter is economy. -
Daved Green at 00:33 AM on 26 January 2010Peer reviewed impacts of global warming
Hi guys , Ive been reading this site for ages now using it to counter deniers claims all good but , these small mistakes means an even greater effort is needed in the wider press to show the science is not weakened . the denier arguement now where i work (basic blue collar industry ) is that all the data is corrupted or faked and he is the proof .I try but my memory fails me and my debating skills :( . We have Monckton here in Australia and hes useing climategate and the glacier 2035 plus something about Darwin temp data being changed to show a warming trend to basically debunk AGW as either a great socialist /facist conspiracy and or scientists on the make for more funds . He will go down a treat here as most average australians dont trust politicians and dont really understand science . Its great all you guys debateing each other here but all this never get out to the general public , the counter arguement is never seen these people like Monckton never really get pulled up and shown to the people how they are misrepresenting the facts . Still this is a great site just wish i could take it with me all the time . -
jpark at 23:48 PM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
HI looks like I have some apologising to do! I think I did say sorry when I went off topic but I was trying to get an answer I understood. I am genuinely interested in the debate and I realise I have a lot to learn. I will keep plugging away and see if I can get it. I guess my instinct would be 'bad data=bad science'. -
Marcus at 23:28 PM on 25 January 2010Peer reviewed impacts of global warming
Ubique, according to everything I've read, the optimum annual average global temperature-at this particular period of history (namely the Holocene) is probably around 14 degrees. This was approximately the temperature in which agriculture & the very first civilizations truly flourished, around 8,000 years ago-with even slight changes, above or below, being fairly detrimental (the collapse of the Mayan, Anasazi & Khmer civilizations-due to mild warming-& the Viking Greenland colony due to the Little Ice Age-come to mind). Of course how detrimental a temperature change can be will also be down to factors like (a) how quickly the change occurs, (b) how marginal the environment is to start with (in terms of soil fertility & precipitation etc), (c) available technology & (c) the willingness of the whole society to make the necessary sacrifices needed to adapt to changing conditions. Ultimately though, given the current speed of change, the fear is that our societies will not be able to adapt quickly enough to global warming-& its attendant consequences-to save ourselves; especially given the penchant for extreme, short-sighted selfishness on the part of certain quarters of society-& so mitigation is seen as our best bet. -
Jesús Rosino at 22:49 PM on 25 January 2010Peer reviewed impacts of global warming
Terrific topic, John. Despite being so relevant, it's not easy to find (at least summarized and well documented) information like this. Next on my list for translation! Riccardo, Chris, Marcus, I find your points of view insightful and thought-provoking. Hope you keep on sharing them with us for long ;-). Cheers.Response: Don't translate just yet - still tweaking and adding papers. Maybe give it a few days. -
Ubique at 22:19 PM on 25 January 2010Peer reviewed impacts of global warming
OK, so what do all you experts out there regard as the optimum average world temperature that will best benefit the current eco system (because this is what all this hot air is really all about) and is it actually possible for us to achieve this utopian situation? John, "Finding it hard to think of a positive impact of sea level rise...” Perhaps a positive impact of sea level rise is that it results from an increase in sea water volume and therefore a greater capacity to sequester the extra CO2?Response: Hmm, higher sea levels leading to more CO2 absorption? Not sure if that's true as the ocean's ability to absorb CO2 is expected to diminish. In fact, evidence indicates this is already happening (Quéré 2007, Schuster 2007, Park 2008). But points for creativity - I never would've thought of that! :-) -
RSVP at 21:00 PM on 25 January 2010Peer reviewed impacts of global warming
What greater form of denial is there than to assume that the Earth's temperature can't change over time, or shouldnt be affected by an overdimensioned human footprint? ...as if Global Warming comes as a surprise and should'nt be happening. And even if Global Warming was a purely natural phenomenon, all these positives and negatives would exist just the same. It should be clear that the problem is compounded due to the order of magnitude of the Earth's current human population. On a similar note, if a city wants to install a nuclear reactor, they should be forced to store the nuclear residuals and waste within the city limits. Similarly, dont try to fool yourself about solar panels and windmills being ecological as you have them spreading all over the Earth's surface. There is no free lunch, but there is a large crew of peer deniers.Response: I know of no climate scientist who asserts Earth's temperature can't change over time. So please refrain from strawman arguments.
It is well established and undisputed that climate changes naturally - because climate is sensitive to radiative forcings. When the sun's output changes, climate changes at a rate of 3°C for every 3.7 Wm-2 of radiative forcing from the sun. This is the same climate that changes at a rate of 3°C for every 3.7 Wm-2 of radiative forcing from CO2. The natural climate change you cite actually provides evidence for the climate's sensitivity to CO2. -
NewYorkJ at 19:39 PM on 25 January 2010Peer reviewed impacts of global warming
"Finding it hard to think of a positive impact of sea level rise..." Think Lex Luthor, Superman One (a relatively patient Lex Luthor, perhaps). The "global warming is good" crowd could play that up. Slowly sink the elite Hollywood celebrities so the rest of us can have beachfront property.Response:Hmm, interesting suggestion. Now if only Lex Luthor had published any peer reviewed papers. In Energy and Environment, maybe? :-)
-
CoalGeologist at 18:51 PM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
Marcus (#13 and other posts above): I concur with your distinction between skepticism and denialism. One way of describing it is that skeptics doubt, while denialists have no doubt. Unfortunately, there are many difficulties in applying these terms in practice. One problem is that denialists typically insist that their position is science-based and falsifiable, if only someone would present them with credible evidence. Of course, this is impossible from a practical standpoint. Another problem is that skepticism is a “slippery slope” to denialism, particularly in the current environment where criticism of AGW is dominated by confusing and ultimately fallacious arguments. Even a well-intended skeptic can end up becoming a denialist without realizing it, while still believing their position(s) to be rational, unbiased, and based on evidence. Another problem is that deniers resent being called "deniers", which unfortunately heightens the emotionalism of the dialog. Ironically, in many cases deniers even resent being called "skeptics"! This might be a hard to understand, since most scientists regard skepticism as an essential component of scientific method, but I interpret it to be because denialists give zero credibility (meaning "absolute zero") to the theory of anthropogenic climate change. From their perspective, they are the possessors of the only scientific truth. Therefore, it should be someone else’s job to play the role of “skeptic” if they wish. In their view, they are not “skeptics” at all, but simply realists. The distinction between skepticism and denialism is important with respect to the current discussion of the surface temperature data. Denial that warming is occurring had faded from popularity, but like so many other "vampire arguments" in this debate, it refuses to die and has enjoyed a recent resurgence. Moreover, it eventually invokes the denialists' fallback position when all else fails: conspiracy theory. -
Peer reviewed impacts of global warming
I am of the opinion that most websites dealing with the issue of climate change, both pro and anti the theory of AGW, are rapidly loosing credibility as they tend to utilize the ‘straw man argument’ which is generally propped up by the postings of sycophants. This approach does not lead to a more informed common understanding of the issue and in fact appears to be polarizing and entrenching opinions with the members of both camps refusing to impartially consider and evaluate differing views and resorting to name calling and demeaning the views expressed by contributors who are not members of what they perceive to be the ‘accepted scientific community’. This is clearly not in the interests of science and undermines efforts to formulate appropriate strategies to enable the human population to respond to changing circumstances, whether these caused by natural processes or human activity or a combination of both. Perhaps Skeptical Science could break the stalemate and before posting an article, why not submit it for review by a credible peer who has a different view (I am sure that many of the 141 signatories to the open letter to the Secretary-General of the United Nations, dated 8 December 2009, would oblige) and then post the article and review simultaneously with both authors being afforded the opportunity to respond to the subsequent postings of the contributors? -
Marcus at 17:22 PM on 25 January 2010Peer reviewed impacts of global warming
HR, that's because it was the end of a mini ice-age. Glaciers were in a very slow retreat throughout the 19th & early 20th century-in line with a solar induced warming trend. Then, around 1950, they stabilized & even grew again, but have been in a state of accelerated retreat for the last 30 years-& are, according to my best information, at levels lower than they've ever been since we first started studying them in the mid 19th century. -
CoalGeologist at 16:56 PM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
kforestcat (Post #17 & 21): The U.S. National Climate Data Center has tried to be clear in explaining the methodology they've used in an effort to optimize the usefulness of the data they are constrained to work with. If you type "NCDC temperature methodology adjustments" into your browser, you'll find plenty of information, including this page: http://www.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html#QUAL As noted by other posters, you can find links to scientific studies assessing the precision and accuracy of the data. Although I find your response (#17) rather draconian, as a U.S. taxpayer I concur with you that our Federal employees should be held to highest performance standards. Assuming you are no less demanding on yourself than you would be toward your PhDs, you might want to consider what measures are appropriate under the circumstances. ;-) (Sorry... This is more of a general response to those whose judgment is swift and merciless (and typically wrong) regarding the quality of data that indicate warming, while being substantially more lenient toward data that appear to show the opposite. Even if one is inclined to be skeptical regarding the accuracy of the surface temperature data, bear in mind that glaciers and ice caps have no political agenda.) -
Doug Bostrom at 16:54 PM on 25 January 2010The chaos of confusing the concepts
Sorry, I did a poor job w/the last sentence of my last post. The point I was trying to make is that the central effects being predicted by climate models are so large as to require a rather enormous and therefore unlikely unidentified lacuna in order to make those central findings significantly less threatening. Steve did a nice thought experiment w/some rough numbers describing a scenario resulting in a discontinuity in the predicted mode of forcing of major scope, yet that change was not enough to fully offset the net impact of our activities. Another more fundamental problem comes along with relying for comfort on model errors of the type envisioned as accompanying failure to identify and include various dynamic features of the climate. For instance, if as Steve hypothesizes we should upset the accustomed thermohaline circulation of the North Atlantic as an upshot of our activities, though it might reduce warming roughly as he suggests we'd still have a major climate disaster on our hands. Errors in models unaccounted for do not change the basic physics underpinning AGW. The energy budget of the planet is being altered and though we may make errors in predicting the effects of that change we're very unlikely to find net benefit as a result. We and the rest of the biological systems here are adjusted for a particular energy budget and if that budget changes too fast we'll have a hard time coping. -
HumanityRules at 16:26 PM on 25 January 2010Peer reviewed impacts of global warming
The problem with the Himalayan glacier data wasn't so much that it wasn't peer-reviewed rather that it was just plain wrong. Peer-reviewed data can just as easily be wrong, especially when its re-inforcing the particular concieved notions and prejudices of the day. Ned post #1 Just to be even more accurate. Global glacier reached their most recent maxima around 1750 and have generally been in retreat ever since. -
Doug Bostrom at 15:45 PM on 25 January 2010The chaos of confusing the concepts
stevecarsonr at 13:18 PM on 25 January, 2010 Good points, and thank you for the illustrations. So in sum insufficient help from turning the subarctic into an ice cube and refreezing the Arctic, unless forcing estimates are wildly inaccurate. I guess that illustrates what I've been thinking, which is that any unidentified issues w/the current crop of models are going to have to be huge and thus likely quite difficult to overlook. -
rrvau at 15:29 PM on 25 January 2010Why is Greenland's ice loss accelerating?
Where did Greenland get its name from? Could have it been "green" at some time when Vikings roamed? Is the ice thinning? I have seen evidence that the warming and cooling, the thickening and thinning of the Arctic (readings from the 80th parallel) has remained remarkably consistent over the past century. Naturally there are deviations from the mean but it shows that it has always thinned and thickened at roughly the same time and rate each year. http://ocean.dmi.dk/arctic/meant80n.uk.php http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm Best Regards, Royce R. Vines Unintended consequences rule when busybodies get on their "high horses" - Emmett -
DonMorton at 15:11 PM on 25 January 2010Why does CO2 lag temperature?
Would somebody please help me understand the fallacies in T.J. Nelson's web page, "Cold Facts on Global Warming" available at http://brneurosci.org/co2.html I've seen some rebuttals dating back to 2005, but this guy seems to update his page quite frequently. His major premise (and the one that denialists seem to grab at) seems to be that the warming response to increased CO2 is logarithmic, and that we are "far out" on the curve, so greater increases in CO2 would result in less and less warming, to the point of being insignificant. -
stevecarsonr at 13:39 PM on 25 January 2010The chaos of confusing the concepts
doug_bostrom: "..unless one can envision a chaotic process that removes heat from the planet. What might that be?" Other effects (apart from THC as already outlined) include aerosols in reflecting incoming radiation and creating more clouds. As the IPCC AR4 (2007) shows, the error bars for aerosols match the size of the CO2 effect. The error bars are there because as yet the effects of aerosols are not really understood. "Medium low level of scientific understanding" is the description by the IPCC. -
stevecarsonr at 13:18 PM on 25 January 2010The chaos of confusing the concepts
doug_bostrom: "how can thermohaline currents affect global temperature?" By refreezing the arctic and northern europe and therefore increasing the albedo of the planet. If the albedo of the planet increases by 1% that's equivalent to about 3W/m^2, or a little more than the current impact of CO2. The current albedo of the northern mid to high latitudes is around 45-55%. If we took an area that was grassland, soil or forest and covered it with snow or ice it would go from around 20% to 60%-80% albedo. If we took ocean and covered it with ice it would go from 6% to 60% albedo. So an extra 7M km^2 of water with ice and an extra 3M km^2 of land with snow/ice would make that change. That's about 50% more sea ice in the arctic at the moment and a pretty big increase in northern europe/n.russia ice & snow. Also, if as a result of the THC shutdown the energy in the climate system is simply "re-arranged" then the tropical/sub-tropical regions will be warmer as a consequence of the northern high latitudes being colder. As energy is radiated at T^4, this will also result in a higher overall radiation. Back of envelope.. 20% of the world's surface decreases from 0 to -5'C and 20% of the world's surface increases from 15-20'C then there will also be a 1.1W/m^2 increase in radiation from the earth's surface (averaged across the whole planet). -
bit_pattern at 12:58 PM on 25 January 2010Peer reviewed impacts of global warming
Can you do a section on natural disasters? It's the latest "scandal" being promoted by The Times, would be good to have something to counter it with. -
NewYorkJ at 12:54 PM on 25 January 2010Peer reviewed impacts of global warming
My contribution (for now): Coastal erosion, with a focus on Nigeria. http://idosi.org/wasj/wasj1(1)/10.pdfResponse: Many thanks for the link, much appreciated! I've added (belatedly) a sea level section to the Positives/Negatives of global warming and included coastal erosion.
Finding it hard to think of a positive impact of sea level rise... -
yocta at 12:34 PM on 25 January 2010Peer reviewed impacts of global warming
RE#19 Chris The physicist Jan Hendrik Schön incident at Bell Labs is probably the worst I've heard of. He went so far as to include the same noise in his data for two experiments done at different temperatures. He eventually got busted due to scientists out there by doing their job. That is, critically assessing other peoples work and independently trying to replicate/verify their results. The only criticism I could have is that his colleagues eagerly slapped their name on his work as part of the "et al" without themselves bothering to check up on it's integrity. And I believe it was the editors of Nature were the ones who first discovered his misconduct. Shouldn't we then be congratulating the peer review system? http://en.wikipedia.org/wiki/Jan_Hendrik_Schön -
Berényi Péter at 12:26 PM on 25 January 2010Peer reviewed impacts of global warming
chris at 10:54 AM on 25 January, 2010: Thanks, chris for the clarification. The IPCC could use whatever it saw fit after all. What passed its own review process, of course ("The circulation process among peer and government experts is very wide, with hundreds of scientists looking into the drafts to check the soundness of the scientific information contained in them"). One can get a clear enough impression about the depth of this process by considering the Himalayan glacier case (10.6.2). I am not allowed to cite or quote anything from it, for in order to access the reviews I was forced to accept a kind of non-disclosure agreement. But anyone can have a look. http://ipcc-wg2.gov/publications/AR4/ar4review_access.html Both the First & Second Order Draft Comments worth reading. Search for Himalaya or glacier. Evaluation is OK, I suppose. Almost all the expert comments are vague, except E-10-468 in First Order Draft Comments. It implies glaciers in the Karakoram region are growing (true) but was dismissed. The Japanese GOVT comment (G-10-121) is the only one which expresses some doubt, if only indirectly. No one notices the year 2035 thing. -
Bern at 12:22 PM on 25 January 2010Peer reviewed impacts of global warming
"Scientific discussion should stick to the evidence, I would have thought." Well said, Chris! "Truth" is a dangerous thing. Just look at the many & ongoing religious wars over whose version of the "Truth" is correct. Lee Grable @ #9: Are you seriously suggesting that the generation of acoustic pressure waves is dependent upon whether there is a human observer present? Amazing, then, how all those animals that evolved in areas with no human population developed such a good sense of hearing... :-) -
PT_Goodman at 12:21 PM on 25 January 2010The IPCC's 2035 prediction about Himalayan glaciers
"In order to the glaciers in the Himalayans to melt completely, the freezing level would have to raise nearly 10,000 feet, for the summer freezing level in the area is about 13,000 ft. If it were to be reduced on a Moist adiabatic lapse rate, that would equate to a surface temperature at the base of the Himalayan Massiff to over 150F, and that is at 5000 ft. Dry adiabatically, it would be nearly 180F... I don't think that area is ready for that, as it would continue to warm gradually down to sea level and that would push it up to nearly 190F in BomBay (Mumbai as they say today). You could fry eggs on the sidewalk, maybe bake bread in a reflection oven, and roast corn on the cob in the same manner." The above is not my argument against the Himalayan glaciers melting. It is from a denialist. I'm brushing up on my physics (my 40 yo B.S. in Math/Physics isn't helping me much, anymore). I do know what an adiabatic lapse rate is, seem to recall that they are an idealization for estimating purposes only (although they do occur fairly precisely), and believe that the scenario described here is neither achievable nor sustainable in the real world (on earth). It would seem that the conditions described here would result in a very unstable atmospheric situation, and quickly and dramatically break down. I'm hoping someone here can provide a more complete refutation, although I'll be looking into it more myself. -
David Horton at 11:58 AM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
I had a great conspiracy theory going there John, and you've ruined it. Perhaps they have exchanged emails ...?Response: Sorry to rain on your tinfoil hat parade :-) -
Marcus at 11:20 AM on 25 January 2010Peer reviewed impacts of global warming
You make a good point there Chris. Why does Peter assume that Peer Review is the "last line of defense" against bodgey science, when in truth it is the 1st & 2nd. Should a error laden paper somehow slip through the cracks, the scientific community as a whole is usually quick to highlight its flaws. Case in point is the original Manne paper relating to Paleo-climatology. Fellow researchers complained to the National Academy of Science, their claims were found to be valid & Manne was forced to redo & resubmit his original paper. If only the non-scientific world were subject to the same levels of scrutiny. Oh, & compare the level of peer-review in ISI journals to that of a journal like Energy & Environment. Remember that awful paper by the biology teacher Beck? The one which apparently proved that CO2 levels were higher in the 19th century than they are today (in spite of error bars which were almost as large as the actual values). That paper was utterly riddled with errors-errors easily pointed out by analytical chemists, atmospheric scientists & the like-yet it still got published, & is now held up as *proof* against global warming by those in the denialist industry. -
Marcus at 11:03 AM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
#60 (dhogaza), yes I found that confusing too, not least because we're not really talking about models in this case-we're talking about directly observed changes in average temperatures. -
Doug Bostrom at 10:54 AM on 25 January 2010The chaos of confusing the concepts
As we while away our Amateur Hours here, lest we get too lost discussing various subsystems it's a good thing to remember that-- chaos at or near the surface or not-- energy has to escape from the Earth if it is not to become warmer. So maybe it would be good to focus on effects that can actually change the planetary radiation equation. It seems to me that it's easy to pay too much attention to surface temperatures, ocean and land. Surface temperatures can be misleading; absent some means for improved radiation from the planet, there is not going to be any net "cooling" in absolute terms going on regardless of what surface dynamics and temperatures indicate. The elephant in the room here is the oceans; energy hidden in the ocean does not disappear. For example, can thermohaline currents affect global temperature? How? If energy is released at a unusually high rate from the oceans in one region it does not follow that it will automatically escape back into space. Focusing on chaotic processes is a bit of a distraction, unless one can envision a chaotic process that removes heat from the planet. What might that be? -
chris at 10:54 AM on 25 January 2010Peer reviewed impacts of global warming
eh? What's "political" about the John Cook's statement you reproduced? "IPCC was in fact bound by its guidelines to rely on nothing but peer reviewed papers." Was it Peter? In the IPCC Procedures Documentation available here [*] it states concerning source material: "Peer reviewed and internationally available scientific technical and socio-economic literature, manuscripts made available for IPCC review and selected non peer-reviewed literature produced by other relevant institutions including industry". [*] http://www.ipcc.ch/organization/organization_procedures.htm "2. Scientific discussion, on the other hand, should stick to truth (not "credibility")." Scientific discussion should stick to the evidence, I would have thought. "Anonymous peer review as such is inherently vulnerable to corruption (or redefinition à la Jones) indeed." In practice, I suspect this isn't much of a problem. If something is publishable it will get published, no question. Of course one might not get one's precious paper in the journal one might have hoped for. The only instance of substantial corruption of the peer review system I'm aware of is the one involving the Soon/Baliunas paper in Climate Research in which a biased editor let through a flawed paper. That was unfortunate, but has little scientific impact, since the scientific community recognises its flaws and ignores it...it's a good example of the "misrepresentation and dirty tricks" that I described in my post above though! There is a bit of a problem with Geophys Res Letters which seems occasionally to allow through some dodgy stuff. But scientificall that doesn't matter - though it helps fuel the misinformation industry... -
Riccardo at 10:52 AM on 25 January 2010We're coming out of the Little Ice Age
michaelkourlas, if 30 years are not enough to determine a trend i do not understand how 10 years can be enough. And it's not just 30 years, although smaller the contribution of ghg is sizeble even in the first half of the last century. Also, that the models did not predict the last 10 years is a mith, not least because they never attempted to predict them. I'd suggest to read how meaningfull comparison should be done. -
michaelkourlas at 10:40 AM on 25 January 2010It hasn't warmed since 1998
Ocean temperature has decreased since 2003. See R.A. Pielke, Sr., Physics Today, 94, Nov. (2008). which contains this graph: LINK
Moderator Response:Actually, the oceans have been warming since 2003. Observations of upper ocean heat show some short term cooling but measurements to greater depths (down to 2000 metres) show a steady warming trend:
However, the ocean cooling myth does seem to be widespread so I'll shortly update this page to clarify the issue. -
David Horton at 10:26 AM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
Doug Bostrom - I reckon "jpark" is another pseudonym for "JohnP" who similarly turned up out of nowhere on "2009-2nd-hottest-year-on-record-sun-coolest-in-a-century" thread. I thought he was just a bot, but if it is the same one here he is actually working away at distraction.Response: Based on their IP address, unlikely - one user is from the UK, the other is from the USA. That is, unless they're using IP mapping, which is unlikely (I have experienced users trying to disguise their IP before but only after I disabled their accounts on multiple occasions). -
michaelkourlas at 10:15 AM on 25 January 2010We're coming out of the Little Ice Age
I understand that the overall global warming trend has gone on for hundreds of years since the little ice age. I am not disputing that. What I am disputing is how much warming there has been since the 1980s, which is the warming we would be responsible for. We only started emitting massive amounts of CO2 in 1945 and the first time the temperature started rising after that was in the late 1970s and early 1980s. Thus, the problem is that all the IPCC looks at to make its predictions and recommendations and such is one 30 year trend from 1980-present. 30 years is not really enough to completely determine whether or not humans are having a sizable impact on the climate system in the first place, but if there is a possibility that last 10 years of that series do not conform to the predictions that the IPCC have made... it really throws the IPCC's predictions into doubt. -
Berényi Péter at 10:10 AM on 25 January 2010Peer reviewed impacts of global warming
doug_bostrom at 06:44 AM on 25 January, 2010: "Better stick to science" Agreed. However, our host made the bold _political_ statement "If the IPCC's mistaken prediction that the Himalayan glaciers would be gone by 2035 taught us anything, it's that we should always source our information from peer reviewed scientific literature" which cannot go unnoticed. What I was trying to set forth is that it was convoluted a bit, mixed two different things up. 1. IPCC was in fact bound by its guidelines to rely on nothing but peer reviewed papers. 2. Scientific discussion, on the other hand, should stick to truth (not "credibility"). IPCC happened to fail on both points. Intentionally, as Dr Murari Lal has admitted: "We thought that if we can highlight it, it will impact policy-makers and politicians". Of course. Impact is urgent, truth can wait. If peer review, scientific honesty or something else served truth better, remains to be seen. Anonymous peer review as such is inherently vulnerable to corruption (or redefinition à la Jones) indeed. Riccardo at 09:10 AM on 25 January, 2010: "Is this supposed to be the proof of non-scientific political bias?" Yes. -
Doug Bostrom at 10:09 AM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
"If the data going into all the trendy models is bad then we, the public, will simply dismiss the model." Whoever said that, thank you, here's another opportunity to point folks to an actual description of models as opposed to rumors about models: http://www.aip.org/history/climate/GCM.htm -
Riccardo at 10:04 AM on 25 January 2010We're coming out of the Little Ice Age
michaelkourlas, global warming didn't stop nor slowed down, at least if you mean the trend. Maybe temperature did, but it has the bad habit of going up and down in the short run; it always did and presumably will continue to do so. And the neither the IPCC nor the climatologists ever said it will not. -
michaelkourlas at 09:58 AM on 25 January 2010We're coming out of the Little Ice Age
Sorry, ignore the part about GISS. Check out the University of Alabama in Huntsville's measurements: http://www.nationalpost.com/893554.bin -
Steve L at 09:52 AM on 25 January 2010Peer reviewed impacts of global warming
Hi John, I'm surprised not to see sea level rise not mentioned on this page. And I didn't see anything about storms, but I could have missed it in a quick reading.Response: I've now added a sea level section to the Positives/Negatives of global warming and welcome any links to papers on the impacts of sea level rise. -
Tony O at 09:46 AM on 25 January 2010Peer reviewed impacts of global warming
Coral reefs http://www.sciencemag.org/cgi/content/abstract/301/5635/955 There is a reference to warming oceans but I can't get into the article. As always it is hard to tease out how much is due to global warming and how much due to other factors. http://www.sciencemag.org/cgi/content/abstract/321/5888/560 One-Third of Reef-Building Corals Face Elevated Extinction Risk from Climate Change and Local ImpactsResponse: Thanks for the links. You can actually access both those papers for free by signing up for a free membership with Science. The first paper doesn't go much into causes of coral degradation. The second paper (Carpenter 2008) looks at the increased risk of coral extinction due to bleaching and diseases driven by warming waters. I've added Carpenter 2008 to the Positives and negatives of global warming. Thanks again, appreciate you tracking those down! -
Vinny Burgoo at 09:46 AM on 25 January 2010Peer reviewed impacts of global warming
The top item in your list of Negatives doesn't inspire much confidence in the objectivity of your selections. You must know that there's a lot of uncertainty about tropical forest growth rates. Many other studies have found accelerated growth and say that it is probably driven by increased CO2 and is probably pan-tropical. The Feeley study found decelerated growth and says that it is probably driven by local weather changes (and perhaps by human interactions - including research activity itself!) and that all such growth trends are strictly regional. So you have chosen an atypical study whose results might not be related to AGW (the study doesn't ascribe the changed weather to human activities) and which claims no more than regional significance and presented it in a way that suggests pan-tropical, anthropogenic significance. At the same time, you have ignored studies that claim pan-tropical significance and an anthropogenic cause but show an opposite, 'Positives' effect. Nice. If you insist on including such an unresolved issue in your tabulation, you might like to balance the Feeley paper with one that finds an increase in tropical forest productivity. Most such papers hypothesize that the observed increase will eventually be reversed by the effects of increased temperature. This one finds no evidence for that happening any time soon: _Effects of rising temperatures and CO2 on the physiology of tropical forest trees_, Lloyd and Farquhar, 2008 http://rstb.royalsocietypublishing.org/content/363/1498/1811.full.pdf Your second item is also regional, so could surely be countered by a study of a different region showing an opposite effect (assuming anyone can get funding for such studies). So is your third - and the model found an increased range and severity for *a* crop disease. It's dishonest to drop the indefinite article, especially when only one small region is covered. Your fourth might have global implications - but not for the real globe. Cattle like to munch young shrubs. Fifth: regional. Sixth: regional. Seventh: unambiguously global. Hurrah! And the study more or less says what you say it says. (Because the study itself is biased in favour of alarmism? Probably. Susan Solomon, innit. But hers is peer-reviewed alarmism, so I'll let you have this one.) Eighth: regional. That's the Agriculture section done with and I've had enough. This is a very silly enterprise. I have no doubt that studies identifying possible negative regional impacts outnumber those that identify possible positives. I also think it's plausible that changing climates will actually have more negative than positive regional impacts. But a tabulation like this isn't the way to prove it. Do you really want to have long lists of single studies with limited geographical scope - single studies whose caveats you ignore and which, in any case, may well have been superseded by more recent research? You're trying to be a one-man IPCC. It's silly. It would be better to point to synthesis studies. Best of all: simply point to the relevant IPCC chapters. * To prove that the above isn't an attempt to hide a failure to come up with peer-reviewed Positives, here are a couple of studies for your lefthand column. They were easily found. Both were included as positives in the recent RealClimate team 'consensus update', _The Copenhagen Diagnosis_. Positives: Agriculture Increasing human water supplies _Projected increase in continental runoff due to plant responses to increasing carbon dioxide_, Betts et al., 2007 http://www.nature.com/nature/journal/v448/n7157/full/nature06045.html Positives: Agriculture The greening of the Sahara _Atmosphere/vegetation feedbacks: A mechanism for abrupt climate change over northern Africa_, Patricola and Cook, 2008 http://www.agu.org/pubs/crossref/2008/2007JD009608.shtmlResponse: Thanks for the feedback. I wasn't aware of Lloyd 2008 - it's apparent that the impact of climate change on forest productivity is an open question so I've removed Feeley 2007 from the list.
Global studies are always preferable over regional studies but this doesn't mean regional studies should be excluded if no global synthesis is available. However, the list should indicate if the study is regional in focus so I've updated some of the text accordingly.
The need for this page is two-fold. One to rebut the common skeptic argument that global warming is good. Secondly (and sadly) because of the persistent campaign to discredit the IPCC. People need reminding that beneath the politics, there is solid peer reviewed science studying the impacts of global warming. This page removes any barriers between the public and the original science.
However, I agree the list is incomplete and in need of improvement - my goal is to refine it over time and replace older studies with newer studies, regional studies with global studies as they become available. Plus I hope to improve the representation of the peer reviewed science as I find the time to read more deeply. Consequently help and feedback is very welcome to improve the content so again, thanks for your very specific suggestions. -
Riccardo at 09:45 AM on 25 January 2010Greenland is gaining ice
From Peru, in fig. 3 they show mass change for the period 2003-2008; fig. 2A shows the cumulative mass loss from 1960. The former is a rate of mass loss, the latter just a mass. r^2 is the so called coefficient of determination. In the case of a simple linear fit it's equal to the square of the correlation coefficient. You may (crudely) interpret it as the fraction of the variation explained by the model curve. -
michaelkourlas at 09:45 AM on 25 January 2010We're coming out of the Little Ice Age
No, I'm not just looking at the CRU measurements. Take a look at NASA's Goddard Institute for Space Studies measuements (http://data.giss.nasa.gov/gistemp/graphs/). They also show global warming slowing down and almost stopping at about 2000. At the very least, if global warming has not stopped, it has definitely slowed down quite a bit, against what the IPCC has predicted. -
Marcus at 09:39 AM on 25 January 2010Peer reviewed impacts of global warming
Absolute rubbish, Berenyi. Peer review-of one form or another-has actually existed for well over 150 years. The only thing which changed is that it went from being an ad-hoc process to being much more organized. It is also nonsense to try & suggest that Peer-review has slowed down the rate of scientific progress. In many fields, progress has gone ahead at an even faster pace (molecular biology & information technology stand out). If anything has stymied the rate of technological progress its the industrial sector, not the scientific community. Many very powerful, vested interests have used a host of measures to try & impede social & technological innovations that threaten said interests-whether via "Think Tanks", political lobbying or the buying & suppression of patents. Though Peer Review is imperfect, it's better than having no oversight of research, & at least the proponents of AGW can cite a wide body of peer-reviewed literature, whilst the denialists are largely forced to rely on information from web-sites like JunkScience.com & Wattsupwiththat or-worse still-joke journals like Energy & Environment. -
chris at 09:34 AM on 25 January 2010Peer reviewed impacts of global warming
re #10 Peer review is a pretty good system Peter. It's a basic quality control for published science, and has the positive effect of ensuring that competent scientists present their work to a good standard (if they wish to publish anywhere of note). Of course it has its flaws (what example of organized human affairs doesn't?). But it's a strong part of the process of dissemination and accumulation of scientific knowledge. And of course it doesn't work in a vacuum. Most published science has already gone over the hurdles of peer review through departmental, conference or funding-source presentations, and once published has to live or die according to subsequent analysis. I wouldn't have said climate science, as science, has any particular problems. Of course it's a science that happens at this particular time to have strong political significance, and therefore it's subject to rather incessant attempts at misrepresentation and dirty tricks. But the best means of dealing with that is to focus on the science (i.e. what's passed the hurdles required to publish in a decent journal). Not sure the IPCC has any particular problems either. It's generally considered to be doing a good job of periodic assessment of the science with a view to informing policymakers and public. Of course it's not perfect either, and (like climate science and scientists in general) is subject to the rather hysterical attempts to make mountains out of molehills. Again the best means of addressing that is to focus on doing a good job. One might counter your assertions with the warning about the perfect being the enemy of the good. But in reality, those that are engaged in hyperbole and over-reaction against real or perceived errors aren't really interested in improving the systems of science...I suspect what they would like is to create the impression that the systems are sufficiently flawed that any old rubbish posted on the internet would have equivalent authority as the science. What a world that would be, eh Peter!? Otherwise, it's not easy to see what the problems are. It's good that errors or instances of poor practice are identified, wouldn't you say? That happens all the time in science (peer-review being part of that process). Identifying errors is the best means of correcting them. Not sure why we have to accompany the identification of errors with bouts of contrived indignation! -
STBro at 09:22 AM on 25 January 2010Does Urban Heat Island effect add to the global warming trend?
>"It's well established that urban areas are warmer than surrounding rural areas. >However, does Urban Heat Island (UHI) contribute to the global warming trend? >Short answer, no. Two thirds of global temperature data comes from ocean records, >free of UHI effect" Let's start with "Two thirds of global temperature data comes from ocean records ..." Looking at http://www.ncdc.noaa.gov/oa/climate/ghcn-daily/index.php?name=coverage It looks like ocean stations comprise the minority of the data. Even if one refers to Hansen, J. and Lebedev, S. 1987. "Global Trendsof MeasuredSurfaceAir Temperature" http://pubs.giss.nasa.gov/docs/1987/1987_Hansen_Lebedeff.pdf and includes shipboard data, it is still hard to account for "two thirds of global temperature data" coming from ocean records. An actual reference list for all that ocean data would really be helpful. I would find it far more credible if the source assertion for ocean temperatures was based on satellite observations rather than surface observations ... Once the actual data source counts can be sorted out, one must then validate that those sources are indeed "free of UHI effect." Specifically, one would need to look a stations in island cities, military bases, and onboard specific platforms. Density considerations are necessary when analyzing instrumentation details on sea going platforms and in coastal installations. I have collected environmental data both on land and at sea, including temperature altitude profile data and bathymetric profile data. When it comes to accounting for UHI, I'd be especially careful to account for it when it's "coming from ocean records." I remain fully skeptical and unconvinced regarding the assertion: "Two thirds of global temperature data comes from ocean records, free of UHI effect. " It would be really useful to overlay geospatial population density, transportation density, and power generation/consumption with respect to the temperature stations under consideration. Shipboard data needs to be corrected for navigational parameters, instrumentation, location and platform type. Finally, going to the Jones et al reference abstract linked in the first paragraph of the blog, one finds "Urban-related warming over China is shown to be about 0.1°C decade−1 over the period 1951–2004, with true climatic warming accounting for 0.81°C over this period." http://www.agu.org/pubs/crossref/2008/2008JD009916.shtml The period spans more than five decades (1951-2004) ... so the UHI effect is 0.5°C. One then examines Jones et al abstract again "Global surface temperature trends, based on land and marine data, show warming of about 0.8°C over the last 100 years." It's not clear from the abstract if Jones et are saying that the total change in their study is (0.81 + 0.5 = 1.3) or (0.81 total). If the first case holds, UHI accounts for 38% of the increase. If it's the latter case, then UHI accounts for 62% of the increase. The question and answer posed by the blog "does Urban Heat Island (UHI) contribute to the global warming trend? Short answer, no" is inconsistent with either case: does it contribute? Yes, either 38% or 62% depending on the case and presuming that the total climatic increase is for the same five decades and not 100 years. If it is for the entire 100 years, then it may well account for the entire change. -
Riccardo at 09:10 AM on 25 January 2010Peer reviewed impacts of global warming
Berényi Péter, I'm shocked. The link you quote provide a whopping 16 non peer reviwed citations, over some 10,000 in the WG2 report. And i found even more, from WMO, World Bank, and the like. Is this supposed to be the proof of non-scientific political bias? -
dhogaza at 09:09 AM on 25 January 2010On the reliability of the U.S. Surface Temperature Record
"Others here have parried my question rather than answered it. Is the actual data duff or not? If the data going into all the trendy models is bad then we, the public, will simply dismiss the model." Sigh. Temperature data doesn't go into the models. Neither the trendy nor the old boring ones. Temperature data is a model *outcome*, not *input*. -
Mother Nature at 09:01 AM on 25 January 2010Skeptical Science now an iPhone app
timbo at 09:02 AM on 15 January, 2010 "I'm waiting for an Andrew Bolt (check him out SS, he's a nutbag, writes for the Herald Sun) article claiming that coz it's snowing in Jan, GW/AGW is a sham" Timbo, Andrew Bolt has used the recent extreme cold snap in the Northern Hemisphere to question predictions that winter snow would become a thing of the past. I have mentioned claims from AGW scientist Dr David Viner's who commented on this. Now I read in today's 'The Australian' that the IPCC is under fire again for making claims linking extreme weather to AGW..... "The world has suffered rapidly rising costs due to extreme weather-related events since the 1970's"- IPCC 4th assessment 2007 THEN.. "we find INSUFFICIENT evidence to claim statistical relationship between global temperature & catastrophic loses"- Muir Woods paper after peer review in 2008 THEN... "We are reassessing the evidence & will publish a report on natural disasters & extreme weather with the latest findings"- IPCC vice chairman Jean-Pascal Van Ypersele- LAST WEEK The worst of all this, was that this was all conveniently ignored before the Copenhagen summit!, why weren't we told this beforehand???
Prev 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 Next
