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Tuesday, 6 August 2013
Environment & Energy reports on the Nature paper we highlighted 2 weeks ago finding no increase of climate variability over the past 50 years. According to the authors, "Our findings contradict the view that a warming world will automatically be one of more overall climatic variation" and "Evidence from Greenland ice cores shows that year-to-year temperature variability was probably higher in some past cold periods." Furthermore, the paper finds, "Many climate models predict that total variability will ultimately decrease under high greenhouse gas concentrations..." The paper corroborates other peer-reviewed papers, the IPCC SREX Report, and the Congressional testimony of Dr. Roger Pielke, Jr. & Dr. John Christy finding no evidence of any increase of extreme weather or climate variability with global warming.
Climate change is a broad and complicated topic, often too complicated for the average person. Instead, most of us get our grasp of climate change by looking out the window or stepping out the front door.
It explains why many people in North America and Europe -- recent victims of sweltering heat waves, droughts, floods and other extreme weather events -- believe climate change is causing ever more drastic weather extremes (ClimateWire, July 24).
That may not be the case around the world, however, according to a recent study by a team of British scientists published in the journal Nature. While regions like North America and Europe have been experiencing greater temperature variability, wild shifts from extreme heat to extreme cold, some parts of the world have been seeing more consistent temperatures.
When taken as a whole, global temperature variability has been nearly constant over the last 50 years, according to Chris Huntingford, lead author of the study and a climate modeler at the U.K. Centre for Ecology and Hydrology, part of Britain's government-funded Natural Environment Research Council.
"The general view of the scientific community is that there will be parts of the world where variability does go down, so to colleagues this is not necessarily a complete surprise," he said. Still, changing climate variability is a complicated and hotly debated subject, and Huntingford said the study was simply for "show and tell" purposes conveying their modeling results.
The study, which calculated the range of average global temperature by year using 50 years of data, nevertheless sparked a ripple of discussion through the scientific community. Jennifer Francis, a research professor at the Institute of Marine and Coastal Sciences at Rutgers University, discussed the paper with a group of other scientists shortly after it was released.
Francis said she thought the title of the study, "No increase in global temperature variability despite changing regional patterns," was "kind of misleading." By looking only at annual temperature differences, she said, the study didn't account for smaller-scale variability relevant to sudden and short-lived extreme weather events.
The study "smooths out a lot of variability that's really relevant for extreme weather events and the kind of changes and patterns that have been happening lately," Francis said.
The study doesn't ignore regional variability, said James Screen, a research fellow at the University of Exeter who was not involved in the study. He added that people tend to ignore global variability trends in favor of their local experiences. "There's always a bias towards the regions where people live and where events happen, and they cause massive economic losses and hardship to people," he said.
The study noted that the greatest recent year-to-year changes have occurred in much of North America and Europe, something confirmed by a separate study last year. The result, according to several scientists, is a misperception across the West that the weather extremes occurring there are occurring everywhere.
According to Gavin Schmidt, a climate modeler for the NASA Goddard Institute for Space Studies, that misperception makes the study's findings "not a particularly dramatic result."
"General statements about extremes are almost nowhere to be found in the literature but seem to abound in the popular media," Schmidt said. "It's this popular perception that global warming means all extremes have to increase all the time, even though if anyone thinks about that for 10 seconds they realize that's nonsense."
What has managed to avoid attention so far is the decrease in climate variability in the tropics, something scientists have been aware of for a while, according to Francis. "As the world warms up in the future, the tropics are basically going to expand, so the fact that they're becoming less variable, I think, is really a reflection of that," she said.
Huntingford and his co-authors do identify one global trend in climate variability likely to pick up speed: a decrease in annual temperature variability. They write that there is already observational evidence that such variability is now decreasing in Europe and North America as the regions overall become warmer.
"If you were in a warming world," Huntingford said, "the years regarded as extreme could definitely become more routine." They suggested -- cautiously, according to Huntingford -- that rapid sea ice melt in the Arctic is one possible driver behind this future decreased variability.
Recent research suggests melting sea ice has been contributing to extreme weather, but as more sea ice melts in warmer months, the variability it provokes could slowly plateau. "We were given the opportunity by Nature to write a speculative last paragraph, and we think that sea ice probably has a major role in this," Huntingford said.
He added, however, that "the [climate] drivers into the future is something that will require a lot more research." Francis expressed a similar sentiment, arguing that many other factors could be contributing to a decreasing variability. "The fact that both basically are steadily changing doesn't mean that they're connected. There are a lot of things in the climate system that are steadily changing," she said.
Scientists assert there is less weather variability, globally, than most people believe
Climate change is a broad and complicated topic, often too complicated for the average person. Instead, most of us get our grasp of climate change by looking out the window or stepping out the front door.
It explains why many people in North America and Europe -- recent victims of sweltering heat waves, droughts, floods and other extreme weather events -- believe climate change is causing ever more drastic weather extremes (ClimateWire, July 24).
That may not be the case around the world, however, according to a recent study by a team of British scientists published in the journal Nature. While regions like North America and Europe have been experiencing greater temperature variability, wild shifts from extreme heat to extreme cold, some parts of the world have been seeing more consistent temperatures.
When taken as a whole, global temperature variability has been nearly constant over the last 50 years, according to Chris Huntingford, lead author of the study and a climate modeler at the U.K. Centre for Ecology and Hydrology, part of Britain's government-funded Natural Environment Research Council.
"The general view of the scientific community is that there will be parts of the world where variability does go down, so to colleagues this is not necessarily a complete surprise," he said. Still, changing climate variability is a complicated and hotly debated subject, and Huntingford said the study was simply for "show and tell" purposes conveying their modeling results.
The study, which calculated the range of average global temperature by year using 50 years of data, nevertheless sparked a ripple of discussion through the scientific community. Jennifer Francis, a research professor at the Institute of Marine and Coastal Sciences at Rutgers University, discussed the paper with a group of other scientists shortly after it was released.
Francis said she thought the title of the study, "No increase in global temperature variability despite changing regional patterns," was "kind of misleading." By looking only at annual temperature differences, she said, the study didn't account for smaller-scale variability relevant to sudden and short-lived extreme weather events.
The study "smooths out a lot of variability that's really relevant for extreme weather events and the kind of changes and patterns that have been happening lately," Francis said.
Misperception in the media
The study doesn't ignore regional variability, said James Screen, a research fellow at the University of Exeter who was not involved in the study. He added that people tend to ignore global variability trends in favor of their local experiences. "There's always a bias towards the regions where people live and where events happen, and they cause massive economic losses and hardship to people," he said.
The study noted that the greatest recent year-to-year changes have occurred in much of North America and Europe, something confirmed by a separate study last year. The result, according to several scientists, is a misperception across the West that the weather extremes occurring there are occurring everywhere.
According to Gavin Schmidt, a climate modeler for the NASA Goddard Institute for Space Studies, that misperception makes the study's findings "not a particularly dramatic result."
"General statements about extremes are almost nowhere to be found in the literature but seem to abound in the popular media," Schmidt said. "It's this popular perception that global warming means all extremes have to increase all the time, even though if anyone thinks about that for 10 seconds they realize that's nonsense."
What has managed to avoid attention so far is the decrease in climate variability in the tropics, something scientists have been aware of for a while, according to Francis. "As the world warms up in the future, the tropics are basically going to expand, so the fact that they're becoming less variable, I think, is really a reflection of that," she said.
Variability may decrease as world warms
Huntingford and his co-authors do identify one global trend in climate variability likely to pick up speed: a decrease in annual temperature variability. They write that there is already observational evidence that such variability is now decreasing in Europe and North America as the regions overall become warmer.
"If you were in a warming world," Huntingford said, "the years regarded as extreme could definitely become more routine." They suggested -- cautiously, according to Huntingford -- that rapid sea ice melt in the Arctic is one possible driver behind this future decreased variability.
Recent research suggests melting sea ice has been contributing to extreme weather, but as more sea ice melts in warmer months, the variability it provokes could slowly plateau. "We were given the opportunity by Nature to write a speculative last paragraph, and we think that sea ice probably has a major role in this," Huntingford said.
He added, however, that "the [climate] drivers into the future is something that will require a lot more research." Francis expressed a similar sentiment, arguing that many other factors could be contributing to a decreasing variability. "The fact that both basically are steadily changing doesn't mean that they're connected. There are a lot of things in the climate system that are steadily changing," she said.
Monday, 5 August 2013
A new peer-reviewed paper published in Energy & Environment:
Why Scientists are ‘Sceptical’ About the AGW Concept
Arthur Rörsch, Peter A. Ziegler
1 The Netherlands
2 Switzerland
Abstract: The strong climate-forcing effect of rising atmospheric CO2 concentrations advocated by the IPCC, is at odds with climate developments during geological, historical and recent times. Although atmospheric CO2 concentrations continuously increased during industrial times, temperatures did not increase continuously to the present level but stagnated or even declined slightly during 1880 to 1900, 1945 to 1977 and again since 1998. Total solar irradiation rose from a low in 1890 to a first peak in 1950 that was followed by a sharp decline ending in 1977, giving way to a period of rapidly increasing radiation peaking in 2002 when solar activity started to decrease, possibly declining to a new Little-Ice-Age type low. The Greenhouse Effect of increasing atmospheric CO2 concentrations, claimed and widely propagated by IPCC, is particularly vexing as it is widely over-estimated without adequate scientific justification. Large observed climate variations documented for geological and historical times, as well as the lack of insight into the behaviour of complex systems, seriously question the Anthropogenic Global Warming (AGW) concept propagated by the IPCC. The climate variability during industrial times was essentially governed by changes in solar activity with increasing atmospheric CO2 content playing a subordinate role. The climate controlling effect attributed by the IPCC to increasing atmospheric CO2 concentrations is rejected since supporting models are not compatible with observations. Lastly, the authors consider from a historical and philosophical science point of view why current mainstream climate change research and IPCC assessments may have been on an erring way for several decades.
Why Scientists are ‘Sceptical’ About the AGW Concept
Arthur Rörsch, Peter A. Ziegler
1 The Netherlands
2 Switzerland
Abstract: The strong climate-forcing effect of rising atmospheric CO2 concentrations advocated by the IPCC, is at odds with climate developments during geological, historical and recent times. Although atmospheric CO2 concentrations continuously increased during industrial times, temperatures did not increase continuously to the present level but stagnated or even declined slightly during 1880 to 1900, 1945 to 1977 and again since 1998. Total solar irradiation rose from a low in 1890 to a first peak in 1950 that was followed by a sharp decline ending in 1977, giving way to a period of rapidly increasing radiation peaking in 2002 when solar activity started to decrease, possibly declining to a new Little-Ice-Age type low. The Greenhouse Effect of increasing atmospheric CO2 concentrations, claimed and widely propagated by IPCC, is particularly vexing as it is widely over-estimated without adequate scientific justification. Large observed climate variations documented for geological and historical times, as well as the lack of insight into the behaviour of complex systems, seriously question the Anthropogenic Global Warming (AGW) concept propagated by the IPCC. The climate variability during industrial times was essentially governed by changes in solar activity with increasing atmospheric CO2 content playing a subordinate role. The climate controlling effect attributed by the IPCC to increasing atmospheric CO2 concentrations is rejected since supporting models are not compatible with observations. Lastly, the authors consider from a historical and philosophical science point of view why current mainstream climate change research and IPCC assessments may have been on an erring way for several decades.
Reblogged from The Climate Skeptics Party, Australia:
Who are the Deniers?
by physicist Dr. Gordon J. Fulks
Global warmers are forever calling those of us who disagree with them 'deniers.' This thinly veiled reference to the Holocaust and the murder of six million people is far from appropriate. Do skeptics deny the Holocaust and the science? Of course not, but it brings up an interesting question:
Who denies natural climate change?
- Who denies the importance of variable solar irradiance and the possible importance of solar modulation of galactic cosmic rays?
- Who denies that our Sun is a variable star?
- Who denies that our oceans contain the vast majority of mobile heat on this planet and therefore dominate our climate, year to year and decade to decade?
- Who denies the importance of natural ocean cycles like the Pacific Decadal Oscillation (PDO), discovered by researchers studying salmon?
- Who denies clear cyclical variations in our climate, easily traceable to ocean cycles?
- Who denies that our recent warming commenced about 1830, long before significant burning of fossil fuels?
- Who denies that ice core data clearly show that recent warming is consistent with previous warm periods, like the Medieval, Roman, and Minoan?
- Who denies that CO2 lags temperature in the ice core data by as much as 800 years and hence is a product of climate change not a cause?
- Who denies 150 years of chemical measurements of atmospheric CO2 that suggest that ice core reconstructions of past CO2 concentrations are low by 60 ppm?
- Who denies that the global temperature went down for three decades after World War II, despite significant increases in human emissions of CO2 due to industrialization?
- Who denies that water vapor is the primary greenhouse gas and by far the dominant climate gas, not CO2?
- Who denies that increasing CO2 is a substantial benefit to plants and therefore helps us feed the seven billion people on this planet?
- Who denies that our oceans are alkaline not acidic and can never turn acidic because of buffering?
- Who denies that the EPA's three "Lines of Evidence" supporting their Endangerment Finding on CO2 are all fatally flawed?
- Who denies the leveling off of the Global Temperature for the past 15 years?
- Who denies that the 'Hotspot' (required by Global Warming theory) does not exist in the tropical troposphere?
- Who denies that all 73 computerized climate models are epic failures?
- Who denies that theories which fail validation tests are dead?
- Who denies the supremacy of evidence over theory?
- Who denies the supremacy of logic and evidence over authority and consensus?
- Who denies that Extreme Weather has always been with us and cannot be traced to CO2?
- Who denies that the Climategate e-mails showed fundamental cheating by those scientists promoting Global Warming?
- Who denies that many prominent scientists oppose climate hysteria?
In short, who denies both the science and the scientific method?
Gordon J. Fulks, Ph.D. lives in Corbett, Oregon, and can be reached at gordonfulks@hotmail.com. He holds a doctorate in physics from the University of Chicago, Laboratory for Astrophysics and Space Research.
Related: Dr. Fulk's recent powerpoint presentation on the EPA endangerment finding
New paper finds Greenland temperatures were ~8C warmer than the present during the last interglacial
A new paper published in Climate of the Past finds that "the previous interglacial (Eemian, 130,000–114,000 years ago) had a mean sea level ...4 to 7 meters above the current level, and, according to climate proxies, a 2 to 6 C warmer Arctic summer climate." The paper also finds temperatures above the Greenland ice sheet were a remarkable 8C higher than the present, far exceeding the most catastrophic of IPCC predictions.
All of which suggests the warming periods of the current interglacial, including the current warm period, are entirely within natural variability, not unprecedented, and not unusual. Furthermore, there is no evidence of a runaway greenhouse effect or runaway positive-feedbacks despite an Arctic climate that was much warmer in the past.
Importance of precipitation seasonality for the interpretation of Eemian ice core isotope records from Greenland
1IMAU, Utrecht University, Utrecht, the Netherlands
2KNMI, De Bilt, the Netherlands
3Deutscher Wetterdienst – DWD, Offenbach, Germany
Abstract. The previous interglacial (Eemian, 130–114 kyr BP) had a mean sea level highstand 4 to 7 meters above the current level, and, according to climate proxies, a 2 to 6 K warmer Arctic summer climate. Greenland ice cores extending back into the Eemian show a reduced depletion in δ18O of about 3‰ for this period, which suggests a significant warming of several degrees over the Greenland ice sheet. Since the depletion in δ18O depends, among other factors, on the condensation temperature of the precipitation, we analyze climatological processes other than mean temperature changes that influence condensation temperature, using output of the regional climate model RACMO2. This model is driven by ERA-40 reanalysis and ECHO-G GCM boundaries for present-day, preindustrial and Eemian climate. The processes that affect the condensation temperature of the precipitation are analyzed using 6-hourly model output. Our results show that changes in precipitation seasonality can cause significant changes of up to 2 K in the condensation temperature that are unrelated to changes in mean temperature.
"Various Greenland ice cores show lower rates of depletion for the Eemian, suggesting that the Greenland Ice Sheet had a significantly warmer climate during the Eemian than today (Johnsen et al., 1997). For example, Eemian δ18O values at NorthGRIP and NEEM are about 3–4‰ higher than present. Using the temperature-δ18O relation observed for the present interglacial, this represents an Eemian warming of 8 ± 4 K (NEEM community members, 2013)"
All of which suggests the warming periods of the current interglacial, including the current warm period, are entirely within natural variability, not unprecedented, and not unusual. Furthermore, there is no evidence of a runaway greenhouse effect or runaway positive-feedbacks despite an Arctic climate that was much warmer in the past.
Clim. Past, 9, 1589-1600, 2013 www.clim-past.net/9/1589/2013/ doi:10.5194/cp-9-1589-2013 |
Importance of precipitation seasonality for the interpretation of Eemian ice core isotope records from Greenland
1IMAU, Utrecht University, Utrecht, the Netherlands
2KNMI, De Bilt, the Netherlands
3Deutscher Wetterdienst – DWD, Offenbach, Germany
Abstract. The previous interglacial (Eemian, 130–114 kyr BP) had a mean sea level highstand 4 to 7 meters above the current level, and, according to climate proxies, a 2 to 6 K warmer Arctic summer climate. Greenland ice cores extending back into the Eemian show a reduced depletion in δ18O of about 3‰ for this period, which suggests a significant warming of several degrees over the Greenland ice sheet. Since the depletion in δ18O depends, among other factors, on the condensation temperature of the precipitation, we analyze climatological processes other than mean temperature changes that influence condensation temperature, using output of the regional climate model RACMO2. This model is driven by ERA-40 reanalysis and ECHO-G GCM boundaries for present-day, preindustrial and Eemian climate. The processes that affect the condensation temperature of the precipitation are analyzed using 6-hourly model output. Our results show that changes in precipitation seasonality can cause significant changes of up to 2 K in the condensation temperature that are unrelated to changes in mean temperature.
A new paper published in Quaternary International reconstructs temperatures in Eastern Siberia over the past 10,500 years and finds "Reconstructed mean July temperatures were equal or up to 1.5 °C higher than today between [6,000 and 5,000 years before the present]" during the Holocene Climate Optimum.
Prior posts on non-hockey sticks
A 380 cm long sediment core from Lake Temje (central Yakutia, Eastern Siberia) was studied to infer Holocene palaeoenvironmental change in the extreme periglacial setting of eastern Siberia during the last 10,000 years. Data on sediment composition were used to characterize changes in the depositional environment during the ontogenetic development of the Lake Temje. The analysis of fossil chironomid remains and statistical treatment of chironomid data by the application of a newly developed regional Russian transfer functions provided inferences of mean July air temperatures (TJuly) and water depths (WD). Reconstructed WDs show minor changes throughout the core and range between 80 and 120 cm. All the fluctuations in reconstructed water depth lie within the mean error of prediction of the inference model (RMSEP = 0.35) so it is not possible to draw conclusions from the reconstructions. A qualitative and quantitative reconstruction of Holocene climate in central Yakutia recognized three stages of palaeoenvironmental changes. The early Holocene between 10 and 8 ka BP was characterized by colder-than-today and moist summer conditions. Cryotextures in the lake sediments document full freezing of the lake water during the winter time. A general warming trend started around [8,000 years before the present] in concert with enhanced biological productivity. Reconstructed mean TJuly were equal or up to 1.5 °C higher than today between [6,000 and 5,000 years before the present] 6.0 ka and 5.0 ka BP. During the entire late Holocene after 4.8 ka BP, reconstructed mean TJuly remained below modern value. Limnological conditions did not change significantly. The inference of a mid-Holocene climate optimum supports scenarios of Holocene climatic changes in the subpolar part of eastern Siberia and indicates climate teleconnections to the North Atlantic realm.
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| Temperature reconstruction shown in first graph at left shows temperatures were up to 1.5C higher than today between 6,000 to 5,000 years ago. Dotted vertical line shows present temperature. |
Prior posts on non-hockey sticks
Holocene climate conditions in central Yakutia (Eastern Siberia) inferred from sediment composition and fossil chironomids of Lake Temje
- a Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg A43, 14473 Potsdam, Germany
- b Kazan Federal University, Kremlyovskaya Street 18, 420018 Kazan, Russia
- c St. Petersburg Gerzen Pedagogical University, Moika 48, 191186 St. Petersburg, Russia
- d North-Eastern Federal University, 58 Belinsky Street, Yakutsk 677891, Russia
Abstract
A 380 cm long sediment core from Lake Temje (central Yakutia, Eastern Siberia) was studied to infer Holocene palaeoenvironmental change in the extreme periglacial setting of eastern Siberia during the last 10,000 years. Data on sediment composition were used to characterize changes in the depositional environment during the ontogenetic development of the Lake Temje. The analysis of fossil chironomid remains and statistical treatment of chironomid data by the application of a newly developed regional Russian transfer functions provided inferences of mean July air temperatures (TJuly) and water depths (WD). Reconstructed WDs show minor changes throughout the core and range between 80 and 120 cm. All the fluctuations in reconstructed water depth lie within the mean error of prediction of the inference model (RMSEP = 0.35) so it is not possible to draw conclusions from the reconstructions. A qualitative and quantitative reconstruction of Holocene climate in central Yakutia recognized three stages of palaeoenvironmental changes. The early Holocene between 10 and 8 ka BP was characterized by colder-than-today and moist summer conditions. Cryotextures in the lake sediments document full freezing of the lake water during the winter time. A general warming trend started around [8,000 years before the present] in concert with enhanced biological productivity. Reconstructed mean TJuly were equal or up to 1.5 °C higher than today between [6,000 and 5,000 years before the present] 6.0 ka and 5.0 ka BP. During the entire late Holocene after 4.8 ka BP, reconstructed mean TJuly remained below modern value. Limnological conditions did not change significantly. The inference of a mid-Holocene climate optimum supports scenarios of Holocene climatic changes in the subpolar part of eastern Siberia and indicates climate teleconnections to the North Atlantic realm.
A new peer-reviewed paper published in Energy & Environment finds there is no agreement between observations and climate model predictions during the last two decades of the 20th century. According to the author, "This finding is shown to put constraints on surface [temperature] trend and Climate Sensitivity, limiting them to values close to zero." The paper adds to several other peer-reviewed publications finding the IPCC estimates of climate sensitivity to CO2 are greatly exaggerated.
The full paper is paywalled, but a 2011 paper by the same author [S. Fred Singer] is available here and comes to similar conclusions.
Inconsistency of Modeled and Observed Tropical Temperature Trends
S. Fred Singer
1Science & Environmental Policy Project, University of Virginia, Arlington, VA 22202
The full paper is paywalled, but a 2011 paper by the same author [S. Fred Singer] is available here and comes to similar conclusions.
Inconsistency of Modeled and Observed Tropical Temperature Trends
S. Fred Singer
1Science & Environmental Policy Project, University of Virginia, Arlington, VA 22202
Abstract: Consistency or lack thereof between observed temperature trends and those predicted by Global Circulation Models (GCMs) are a contentious though important issue. The lack of consistency between observed and modeled temperature trends has frequently been used to argue against a significant human contribution to global warming - and vice versa. We present here additional and independent evidence that there is no agreement between observed and modeled warming trends in the tropical troposphere during the last two decades of the 20th century. This finding is shown to put constraints on surface trend and Climate Sensitivity, limiting them to values close to zero.
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