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Bishop Hill Sep 11, 2015 Climate: Surface The Arctic death spiral seems to have been postponed for another year. Based on the Danish graphs below, it looks as if the summer minimum may have been reached, although it is not beyond the realm of possibility that we get another downtick.
;)
Bishop Hill Sep 7, 2015 Climate: Surface Climate: WG2 ;)
The ambulance chasers are still, rather disreputably, hovering around the fringes of the migrant crisis. Today I came across a cartoon that again seeks to link the 2007 Syrian drought to climate change. Entitled Syria's Climate Conflict, it opens with the 2007 drought and then moves on to the displacement of people thereafter, before moving on to the uprising itself, describing its beginnings in the southern city of Daraa and the spread to Damascus before asking whether maybe climate change had something to do with it. A scientivist type is on hand to insinuate that it did.
If you take a look at the cartoon though, you will notice something odd: there is not even a vague insinuation that the climate in Syria has changed. There has been a drought of course, but Syria is nothing if not a country prone to drought. So where is the climate change? It is so transparently an attempt to use a weather event to advance a climate argument that it is hard to avoid the conclusion that the authors are not just playing fast and loose with the facts.
Bishop Hill Sep 5, 2015 Climate: Surface The current El Nino is rousing our green friends into a frenzy as they anticipate all the lurid headlines they will be able to generate at Paris (this is, admittedly, before the year is actually finished, but that has never been much of a concern to the tree hugger).
But questions keep nagging away. If surface temperatures are blipping upwards, why does the pause continue in the satellite record? That's what happened in the 1998 super El Nino.
;)
Similarly, 1998 was hot here in the UK, but the current El Nino seems to have had negligible effect on the British Isles. Indeed, if anything, the opposite.
;)
Bishop Hill Sep 3, 2015 Climate: Surface Climate: WG2 Polar bears are remarkable creatures, but I bet you don't know just how remarkable they are. Scientists tracking some of these majestic beasts in the Southern Beaufort sea using radio-collars have determined that some of them spent the whole of the month of August in an area in which there was almost no sea ice! ;)
Bishop Hill Aug 14, 2015 Climate: Models Climate: Surface ;)
As the latest paper to try to explain the pause appears, it's hard not to smile. Reason follows explanation follows rationale follows excuse, and the interested layman is left with the abiding impression that the night remains very very dark indeed.
This is not to say that these are not valiant efforts to get to the bottom of things, but let us not kid ourselves, a la Guardian, that anyone really has much of a clue about what is going on yet. Claims that climate models are even more accurate than previously thought are the scientific equivalent of a fart joke and deserve the same response.
Bishop Hill Jul 30, 2015 Climate: Models Climate: Surface A new paper by Kevin Cowtan et al claims that the divergence of models and observations is not as big as we thought.
Global mean temperatures from climate model simulations are typically calculated using surface air temperatures, while the corresponding observations are based on a blend of air and sea surface temperatures. This work quantifies a systematic bias in model-observation comparisons arising from differential warming rates between sea surface temperatures and surface air temperatures over oceans. A further bias arises from the treatment of temperatures in regions where the sea ice boundary has changed. Applying the methodology of the HadCRUT4 record to climate model temperature fields accounts for 38% of the discrepancy in trend between models and observations over the period 1975-2014.
It sounds a bit odd to me, but I don't have a copy as yet, so I'm going to hold off further comment for the minute. One assumes though that even if the findings are sound the divergence of satellite temperatures from the models is unaffected.
Bishop Hill
Thanks to readers who have sent the paper along. Here's what the authors have done:
Global averages of the observational temperature records are typically compared to near surface air temperature from an ensemble of climate model simulations...most studies have used the surface
air temperature field from models rather than blended land-ocean temperatures...A true like-with-like comparison would involve blending the air and sea surface temperature fields from the models in a manner consistent with the observational records. The purpose of this work is to evaluate the impact of comparing air temperatures from models with the blended observational data, and to establish guidelines for the determination of blended temperature comparisons.
This seems unexceptionable to me.
Bishop Hill Jul 30, 2015 Climate: Surface The Scotsman is reporting that gritting lorries have been out on the streets in rural Perthshire overnight, with forecasters pointing to the possibility of snow, hail and frost.
It's a worry, this global warming stuff.
Bishop Hill Jul 23, 2015 Climate: Surface Climate: Ward Media IPSO has published its latest judgement on a case brought by Bob Ward against David Rose, the third in as many years. This revolved around a story last year about GISS's claim that 2014 was the warmest on record and their failure to note the significant possibility that that it might not be.
I must say this seemed a relatively small point to me, but it clearly got Bob Ward's blood boiling, in the way that the Jesuits would get a bit upset over minor theological transgressions. It's not so much the details of the offence as the source of the challenge to authority that upsets. No quarter for heretics.
Bishop Hill Jun 15, 2015 Climate: Surface The Committee for Skeptical Inquiry have issued a challenge to the Heartland Institute - one of those climate bets that come along to enliven things for us from time to time. I must say, I think it would have helped if they had got someone who spoke English to write the text for them, because I'm not entirely clear what the bet is.
The Committee for Skeptical Inquiry (CSI) hereby presents to the Heartland Institute a challenge as to whether the Earth’s climate will set a new record high temperature this year. The challenge will be settled using the NASA GISS mean global land surface temperatures for the conventional climate averaging period (defined by the World Meteorological Organization as 30 years) ending on December 31, 2015. If the global average temperature does not exceed the mean temperature for an equal period ending on the same date in any previous year for which complete data exist, CSI will donate $25,000 to a nonprofit to be designated by Heartland. Otherwise, Heartland will be asked to donate $25,000 to a science education nonprofit designated by CSI. It is CSI’s intent to repeat this challenge every year for the next 30 years.
I think they are saying that they expect the 30 year mean to be higher each year than any other 30 year mean on record. If so then the bet is obviously piffle. The annual temperature could fall dramatically this year and the 30-year mean would still increase.
Bishop Hill Jun 4, 2015 Climate: Oceans Climate: Surface Over the last few days I have been copied in on a great deal of correspondence about a new paper in Science from Tom Karl and colleagues, which has "blatant act of political propaganda" written all over it. The claim is that the pause in surface temperature rises is an artefact of the data and that a great deal of jiggery pokery is peformed on the numbers it is possible to get a graph that shows continued warming. The pause is no more.
This could only be written with Paris in mind.
Fortunately, Science distributed the paper to journalists sufficiently early for it to be widely circulated and quite a few people have now had a look. Some of them have even stopped laughing for long enough to write down their thoughts.
Bishop Hill May 15, 2015 Climate: Surface
Updated on May 15, 2015 by
Bishop Hill
For those who have been following the unfolding saga of the latest Lew paper, the said work of art has now been published at Global Environmental Change. There is little that will cause anyone any great surprise - it's all out of the standard Lewandowsky playbook: strawman following nonsense following outright falsehood. Take the case he outlines for why there is no pause:
Claims about a “pause” typically invoke a period commencing in 1998; the top panel of the figure shows that that year saw particularly high temperatures owing to an extreme El Niño event. When this single outlying year is omitted (as illustrated in the bottom panel), the purported pause in warming is no longer apparent. Statistically, what one observes is a decrease in the rate of warming—a slowdown, if you will—but this slowdown is at most modest: during the last 15 years (1999–2013) the linear trend is .13 °C/decade, compared to the trend for the overall period (1970–2013) which is .18 °C/decade. It is only when 1998 is arbitrarily used as the starting point to define the “pause” that the recent rate of global warming has been appreciably lower (.10 °C/decade) than the long-term trend.
Bishop Hill Mar 31, 2015 BBC Climate: Sceptics Climate: Surface I caught most of Costing the Earth today, in which some of the problems with mainstream climate science were discussed. It featured a bunch of alarmists and ex-alarmists discussing aspects of the science that they had until quite recently decried sceptics for mentioning. Towards the end they wondered whether sceptics shouldn't perhaps be admitted to the debate. I'm not sure that they quite grasped the irony of this position and certainly, when the presenter asked about sceptics being presented as crackpots, nobody deigned to answer.
Bishop Hill Feb 21, 2015 Climate: Parliament Climate: Surface According to the Daily Caller, Republicans in the US Congress seem set to announce hearings into the surface temperature records. This intelligence was based on a tweet from Dana Rohrabacher, the vice chairman of the House Science, Space and Technology Committee.
@caerbannog666 expect there to be congressional hearings into NASA altering weather station data to falsely indicate warming & sea rise
— Dana Rohrabacher (@DanaRohrabacher) February 20, 2015
It seems fairly clear that the surface stations are a shambles. It is not so obvious that this has led to a material overstatement of warming. But I think we can say with some certainty that a congressional hearing is probably not going to get to the bottom of the scientific issues.
Bishop Hill Feb 16, 2015 Climate: Models Climate: Surface Climate: WG2 Royal Society In the wake of the Royal Society's recent quick guide to climate change, the Australian Academy has produced their own newbies' guide which can be seen here.
It contains some interesting bits and bobs, for example this bit on extreme rainfall.
Heavy rainfall events have intensified over most land areas and will likely continue to do so, but changes are expected to vary by region.
Bishop Hill Jan 17, 2015 Climate: Statistics Climate: Surface
Updated on Jan 17, 2015 by
Bishop Hill
Many scientists on the whole seem to have been suitably cautious about alleged record-breaking temperatures, taking care to place the new data in the context of the error bars. It's also fair to say that others have been a bit wild.
The Science Media Centre has a couple of moderately level-headed responses, from Tim Palmer and Rowan Sutton, but as always with the SMC it's seen as important to get some input on climate change from a paleopiezometrist, from whom we learn that:
The new global temperature record announced today completely exposes the myth that global warming has stopped.
