How the IPCC fools everyone that CO2 drives climate instead of the Sun

The IPCC claims that only an increase in man-made greenhouse gases can explain most of the global warming observed during the 20th century. To justify this position, the IPCC programs computer models with multiple dubious assumptions, such as in the graph below showing assumed values in the models:

1. Greatly exaggerated, alleged radiative forcing at the top of the atmosphere from increased greenhouse gases [mostly CO2]  of 2 W/m2 from 1959-2000, even though the "IPCC formula" found in the fine print of AR4 predicts a much smaller change of 0.837 W/m2 [58% less] during the same period [5.35*ln(369.52/315.97) = 0.837 W/m2].

2. No change in forcing due to changes in cloud cover, even though multiple papers show a decrease in cloudiness observed in the late 20th century could alone account for all observed global warming. 

3. The false assumption that the effect of solar radiation on the Earth's surface can be modeled by tiny changes in Total Solar Irradiance [TSI] at the top of the atmosphere, shown in the graph below as the blue line. The models falsely assume there has been no change in solar radiation at the Earth surface from the 1930's to the end of the 20th century. In reality, multiple papers have shown the effects of solar radiation at the Earth surface are greatly modified and amplified by changes in clouds, ozone, large changes in solar UV and the solar magnetic field, aerosols, and other factors. Observations have shown swings of solar radiation at the Earth surface of 5 W/m2 over the past 18 years alone [1987-2005], far more than the ~0.25 W/m2 ripples and zero net change of TSI assumed in the blue line below.

4. That the effects of volcanic eruptions are accurately modeled, even though this has been shown to be false, and which also has large effects upon solar radiation at the Earth surface.

5. That long-term trends in ocean oscillations can be ignored in the models, and which also have been shown to correlate with solar activity.

6. That chaotic systems [the ultimate example of which is the climate] can be modeled by linear assumptions. 

7. That increased CO2 will cause an increase in atmospheric water vapor, even though observations show a decline in atmospheric water vapor. 

8. That water vapor acts as a positive feedback, even though observations clearly demonstrate that water vapor acts as a negative feedback. 

9. That increased CO2 will heat the oceans [71% of Earth's surface], even though observations show the ability of doubled CO2 to heat the oceans is essentially zero. 

The IPCC climate models are little more than computer games built upon multiple absurd assumptions and circular reasoning. They do, however, serve the purpose of fooling most of the people, all the time. 

Radiative forcing assumptions in IPCC computer models. Source

Another source of assumptions programmed in the models.

Evidence solar radiation dominates climate change, not greenhouse gases

A poster presentation from Institute for Atmospheric and Climate Science - ETH Zurich finds that "Diurnal temperature range, solar radiation and sunshine duration are closely correlated on decadal timescales." The authors also conclude, "solar radiation has experienced not only a brightening towards the end of the 20th century, but also an earlier period of brightening in the first half of the last century." Figure 2 from the poster shows a dimming of solar radiation at the surface of the Earth during the 70's ice age scare from 1970 to ~1987, and a subsequent brightening of solar radiation by almost 5 W/m2 from ~1987 to the end of the record in 2005. The data shows the change in solar radiation corresponds to an increase in diurnal temperature range anomalies by almost 0.5C. 

By way of comparison, the IPCC alleges that a doubling of CO2 levels would increase forcing at the top of the atmosphere by 3.7 W/m2 and at the Earth surface by only about 1 W/m2. Using the actual change in CO2 levels between 1987 and 2005, the IPCC formula alleges forcing from CO2 increased only 0.45 W/m2 at the top of the atmosphere [5.35*ln(379.80/349.16)] and a mere 0.12 W/m2 [1/3.7*0.45] at the Earth surface from 1987 to 2005. 

The data also show an excellent correlation between solar radiation at the surface and diurnal temperature range (R² of = 0.87), which far exceeds the correlation between CO2 and temperature (R² = 0.44). Thus, changes in solar radiation at the Earth surface dominate climate change, not greenhouse gases. 

Evidence for increasing solar radiation during the early 20th century

Knut Makowski, Marc Chiacchio, Arturo Sanchez-Lorenzo & Martin Wild

Introduction:

The diurnal temperature range (DTR), which is defined as the difference between daily maximum and minimum temperature is considered a useful measure to investigate the development of local and regional changes in the energy balance because it is strongly influenced by its most important element - the incoming solar radiation (Makowski et al. 2008). The recently identified increase of DTR over Western Europe since 1985, is subsequent to the well known decrease since 1950, both are in line with the Global Dimming and Brightening phenomenon. Consequently, we extended our investigations on DTR back to the first half of the 20th century. In a previous study we focused on the influence of solar radiation on DTR, this time we aim at learning more on the evolution of solar radiation using our DTR series as proxies. To strengthen our findings we used several independent datasets for our investigation:

I. ECAD century station data with data back to at least 1918 (1900-2005) - DTR anomalies
II. GEBA database for Europe (1970-2005) - Solar radiation anomalies
III. ECAD & additional sites (Makowski et al. 2006 & 2008), neighbouring GEBA sites (<200km span="span">
IV. gridded version of the ECAD dataset (1950-2002) - DTR anomalies
V. gridded version of the CRU TS 2.1 dataset (1901-2002) - DTR anomalies
VI. ECAD & additional sites (Sanchez-Lorenzo et. al 2008) of sunshine duration (1910-2004) - Sunshine duration anomalies

Diurnal temp range anomaly in blue shows excellent correlation with solar radiation anomalies in red and an increase of almost 5 W/m2 since ~1987.

 

Conclusions:

 • [Diurnal temperature range], solar radiation and sunshine duration are closely correlated on decadal timescales. 

 • The proxies, [diurnal temperature range] and sunshine duration suggest that solar radiation has experienced not only a brightening towards the end of the 20th century, but also an earlier period of brightening in the first half of the last century.

Paper finds 'brightening' of sunshine hours since 1980

A paper published in the Journal of Geophysical Research examined sunshine hours over the Iberian Peninsula from 1961-2004. The authors find a dimming of sunshine occurred from 1961 to the early 1980's, corresponding to the ice age scare of the time. Conversely, the authors find, "Since the early 1980s, the [sunshine duration] series exhibit an upward trend or “brightening,” which corresponds to the subsequent warming period. The authors also find a relationship between sunshine and atmospheric circulation patterns, stating, "Finally and perhaps surprisingly, the [total cloud cover] residual [sunshine duration] series exhibits a statistically significant relationship with a regional atmospheric circulation pattern during spring, summer, and autumn." The IPCC, however, dismisses the role of the Sun in climate change by only examining small changes in Total Solar Irradiance [TSI], while ignoring sunshine hours at Earth's surface, the effect of cloud variations on sunshine, and amplifying factors on sunshine such as clouds/cosmic rays, ozone, large changes in solar UV and the solar magnetic field within and between solar cycles, solar effects on ocean oscillations and atmospheric patterns, etc., etc.

Related:
New paper finds significant increase in solar UV radiation over past 14 years

New paper shows yet another way the Sun controls climate - via ocean oscillations

New paper finds another mechanism by which the Sun controls climate

New paper finds solar influence on El Niño and La Niña cycles

New Paper: Solar irradiance at Earth surface varies up to 24 times more than expected

Paper shows climate models underestimate cooling effect from clouds by a factor of 4

New paper finds sunshine has increased in Iran over past 26 years

New paper shows dimming of sunshine during the 1970's ice age scare, and brightening since the 1980's

Paper finds climate is 'highly sensitive to extremely weak' changes in solar activity

Daily mean sunshine hours anomaly over the Iberian Peninsula for cloud-free sky conditions

JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114, D00D09, 17 PP., 2009
doi:10.1029/2008JD011394

Dimming/brightening over the Iberian Peninsula: Trends in sunshine duration and cloud cover and their relations with atmospheric circulation

Arturo Sanchez‐Lorenzo

Group of Climatology, Department of Physical Geography, University of Barcelona, Barcelona, Spain

Josep Calbó

Group of Environmental Physics, University of Girona, Girona, Spain

Michele Brunetti

Institute of Atmospheric Sciences and Climate, Italian National Research Council (ISAC‐CNR), Bologna, Italy

Clara Deser

National Center for Atmospheric Research, Boulder, Colorado, USA

This study analyzes the spatial and temporal changes in sunshine duration (SunDu) and total cloud cover (TCC) over the Iberian Peninsula (IP) and four subregions during 1961–2004 using high‐quality, homogenized data sets. The analyses confirm that over most of the IP and in most seasons, SunDu and TCC variations are strongly negatively correlated, with absolute values ∼0.8–0.9. Somewhat weaker correlations (0.5–0.6) are found in the southern portion of the IP in summer. A large discrepancy between the SunDu and TCC records occurs from the 1960s until the early 1980s when the SunDu series shows a decrease that it is not associated with an increase in TCC. This negative trend or “dimming” is even more pronounced after removing the effects of TCC via linear regression. Since the early 1980s, the SunDu and TCC residual SunDu series exhibit an upward trend or “brightening.” In addition to the long‐term dimming and brightening, the volcanic eruptions of El Chichon and Mount Pinatubo are clearly evident in the TCC residual SunDu record. The TCC and SunDu records over the IP are well correlated with sea level pressure (SLP), with above normal TCC and below normal SunDu corresponding to below normal SLP locally in all seasons. The TCC and SunDu related SLP changes over the IP in winter and spring are part of a larger‐scale north‐south dipole pattern that extends over the entire Euro‐Atlantic sector. Other more regional atmospheric circulation patterns, identified from rotated principal component analysis, are also linked to TCC and SunDu variations over the IP. Finally and perhaps surprisingly, the TCC residual SunDu series exhibits a statistically significant relationship with a regional atmospheric circulation pattern during spring, summer, and autumn.

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New paper shows dimming of sunshine during the 1970's ice age scare, and brightening since the 1980's

A paper published today in Atmospheric Chemistry and Physics examined trends in surface solar radiation [SSR] over Switzerland from 1885-2010. The authors find surface solar radiation increased during the 1930-1940's and then declined until the ice age scare of the 1970's, followed by an  increase over the period 1980-2010. These variations are inversely correlated to cloud cover, and correlate with global temperature variations much more than the steady rise in CO2 levels over these periods. The surface solar radiation measurements show variations of about 10 W/m2, around 10 times the alleged surface forcing from a doubling of CO2 levels.

According to the authors, 

"A dimming (brightening) is clearly visible in all-sky SSR during the 1950s–1970s (1980s–2000s) subperiod, in line with previous studies that used a lower density of stations. Equally, there is a brief early brightening period in Switzerland restricted to the 1940s, with a lack of significant decadal variations in the preceding period"

The paper corroborates others which have shown from various sites that surface solar radiation has markedly increased since the 1980's, primarily due to a decrease in cloud cover.

Related:

New paper finds large increase in sunshine since the 1980's; dwarfs alleged effect of CO2

New paper finds sunshine has increased in Iran over past 26 years

New paper finds cloudiness in Spain has significantly decreased since 1960

All-sky surface solar radiation shown in top graph. Second graph shows Total Cloud Cover anomalies [TCC]

Atmos. Chem. Phys., 12, 8635-8644, 2012
www.atmos-chem-phys.net/12/8635/2012/
doi:10.5194/acp-12-8635-2012
Decadal variations in estimated surface solar radiation over Switzerland since the late 19th century

A. Sanchez-Lorenzo and M. Wild
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
 Abstract. Our knowledge on trends in surface solar radiation (SSR) involves uncertainties due to the scarcity of long-term time series of SSR, especially with records before the second half of the 20th century. Here we study the trends of all-sky SSR from 1885 to 2010 in Switzerland, which have been estimated using a homogenous dataset of sunshine duration series. This variable is shown to be a useful proxy data of all-sky SSR, which can help to solve some of the current open issues in the dimming/brightening phenomenon. All-sky SSR has been fairly stable with little variations in the first half of the 20th century, unlike the second half of the 20th century that is characterized also in Switzerland by a dimming from the 1950s to the 1980s and a subsequent brightening. Cloud cover changes seem to explain the major part of the decadal variability observed in all-sky SSR, at least from 1885 to the 1970s; at this point, a discrepancy in the sign of the trend is visible in the all-sky SSR and cloud cover series from the 1970s to the present. Finally, an attempt to estimate SSR series for clear-sky conditions, based also on sunshine duration records since the 1930s, has been made for the first time. The mean clear-sky SSR series shows no relevant changes between the 1930s to the 1950s, then a decrease, smaller than the observed in the all-sky SSR, from the 1960s to 1970s, and ends with a strong increase from the 1980s up to the present. During the three decades from 1981 to 2010 the estimated clear-sky SSR trends reported in this study are in line with previous findings over Switzerland based on direct radiative flux measurements. Moreover, the signal of the El Chichón and Pinatubo volcanic eruption visible in the estimated clear-sky SSR records further demonstrates the potential to infer aerosol-induced radiation changes from sunshine duration observations.

The full paper is available here:  Final Revised Paper (PDF, 4512 KB)   Discussion Paper (ACPD)   

New paper shows how natural variability controls North Atlantic climate

A new paper published in Nature Geoscience reconstructs the North Atlantic Oscillation, a natural climate phenomenon that is the "dominant mode of atmospheric variability" of the North Atlantic region.  The authors find that over the past 5,200 years, when the North Atlantic Oscillation (NAO) index is positive, "Europe and the eastern US are mild and wet, whereas Greenland and northern Canada are cold and dry. A negative index is associated with the reverse pattern." The authors also show that modern measurements of the summer NAO index have been strongly negative since about 2005, and thus, Greenland and northern Canada would be expected to be relatively warm and wet relative to Europe and the eastern US. Once again, natural climatic variations such as the NAO have been shown to dominate climate, not greenhouse gases. 

Summer NAO index (June, July, August or JJA) shown in upper left graph has been strongly negative since ~2005.

NAO index over the past 5,200 years shown in 3rd graph from right with positive index in red and negative in blue. "Greenland warm relative to Europe" shown in far right graph.

Variability of the North Atlantic Oscillation over the past 5,200 years

• Jesper Olsen,
• N. John Anderson
• & Mads F. Knudsen

• Affiliations
• Contributions
• Corresponding author

Nature Geoscience

 

(2012)

 

doi:10.1038/ngeo1589

Received

 

29 May 2012 

Accepted

 

24 August 2012 

Published online

 

23 September 2012

Article tool

Climate in the Arctic region and northwestern Europe is strongly affected by the North Atlantic Oscillation^1, 2 (NAO), the dominant mode of atmospheric variability at mid-latitudes in the North Atlantic region. The NAO index is an indicator of atmospheric circulation and weather patterns: when the index is positive, Europe and the eastern US are mild and wet, whereas Greenland and northern Canada are cold and dry. A negative index is associated with the reverse pattern. Reconstructions of the NAO have so far been limited to the past 900 years³. Here we analyse a 5,200-year-long, high-resolution lake sediment record from southwestern Greenland to reconstruct lake hypolimnic anoxia, and link the results to an existing reconstruction of the NAO index from tree rings and speleothems³. Using the relationship between the two records, we find that around 4,500 and 650 years ago—around the end of the Holocene Thermal Maximum and the beginning of the Little Ice Age, respectively—the NAO changed from generally positive to variable, intermittently negative conditions. We suggest that variability in the dominant state of the NAO tend to coincide with large-scale changes in Northern Hemisphere climate. However, the onset of the Medieval Climate Anomaly was not associated with any notable changes in the NAO.

Paging PBS: New paper finds over 4°C urban heat island effect

A paper published in Theoretical and Applied Climatology finds that between 1965 - 2006, urban regions in the Anatolian Peninsula, Turkey experienced a strong urban heat island effect of over 4°C, while surrounding rural areas showed no statistically significant warming at all.

Related: 
http://www.examiner.com/article/pbs-gets-attacked-for-showing-balanced-global-warming-piece

http://wattsupwiththat.com/2012/09/18/pbs-backtracks-due-to-viewer-pressure/#more-71227

http://hockeyschtick.blogspot.com/search?q=%22urban+heat+island%22&max-results=20&by-date=true

From the latest NIPPC Report:

Urban heat islands of the Anatolian Peninsula


Reference:   Ozdemir, H., Unal, A., Kindap, T., Turuncoglu, U.U., Durmusoglu, Z.O., Khan, M., Tayanc, M. and Karaca, M. 2012. Quantification of the urban heat island under a changing climate over the Anatolian Peninsula. Theoretical and Applied Climatology 108: 31-38.

The Anatolian Peninsula comprises the Asian part of Turkey, lying in the Eastern Mediterranean at the confluence of Europe, Asia and Africa, the urban population of which grew from about 25% of its total in 1945 to approximately 45% in 1980 and then, more rapidly, to close to 80% in 2007.

Focusing on cities having over half a million inhabitants representative of urban conditions and much smaller towns representative of rural conditions - all of which also possessed continuous high-quality temperature data from 1965 to 2006 - Ozdemir et al. (2012) studied the four-decade trends in daily minimum air temperature at each location.

In discussing their findings, the eight researchers report that "statistical analysis of daily minimum temperatures for the period between 1965 and 2006 suggest that there is no statistically significant increase in rural areas." However, they say that all of the urban sites, as well as the differences between urban and rural pairs, show significant increases in temperature, indicative of a strong urban heat island (UHI) effect over the region. In fact, as they describe it, the average "urban station is over 4°C warmer than rural."

Whereas it is claimed by many climate alarmists that adequate adjustments are made for urban heat island effects when compiling data from all around the world to deduce a global mean near-surface air temperature representative of non-urban conditions, questions remain as to what extent the world's many urban sites have had their warming reduced to zero over various time intervals (especially more recent ones), as would appear to be needed on the Anatolian Peninsula. If this has not been done there, as well as at other locations where it may have been warranted, it could well be that historical greenhouse gas-induced global warming has not been nearly as large as it has been portrayed to be.

GRACE satellite data shows Antarctica is gaining ice mass

Antarctica is home to 90% of the world's ice mass. Although Antarctic sea ice is currently at a record high and recent research predicts Antarctic land ice will continue to grow during this century, some warmists continue to believe that Antarctica is melting down. Additional evidence shows that the "most vulnerable" portion of Antarctica, the Antarctic Peninsula, has gained up to 45 meters of ice over the past 155 years. Gravitational data from the GRACE satellites also show that the vast majority of Antarctica is gaining, not losing, mass. Trend plots from the GRACE data browser, using all available online data, show that Antarctica has continued to gain mass since the beginning of the mission in 2001:

Trend of ice mass [bottom] for dark orange region over Antarctica. 

Trend of ice mass [bottom] for intermediate orange region over Antarctica

Trend of ice mass [bottom] for light orange region over Antarctica

Trend of ice mass [bottom] for  yellow region over Antarctica

Trend of ice mass [bottom] for light green region over Antarctica

Trend of ice mass [bottom] for aqua region over Antarctica. Note: this small portion of Antarctica is the only region showing a declining trend. 

Related posts Antarctic

Related posts Antarctica

New paper shows Canadian temperatures as warm or warmer than the present many times over past 785 years

A paper published today in Quaternary Research reconstructs June-July temperature trends from the British Columbia Coast Mountains in Canada over the past 785 years from 1225-2010. The paper shows temperatures were as warm or warmer than the present [2010] during many periods in the past including around ~ 1240, 1270, 1310, 1340, 1400, 1460, 1500, 1550, 1590, 1660, 1670, 1710, 1820, and 1930-1940.

Reconstructed June-July temperature anomalies from 1225-2010 from Fig. 6 below. Added red line shows temperature anomaly at the end of the record in 2010. 

Figure 6. Reconstruction of air temperature anomaly ring-width variability AD 1225–2010. (a) June–July air temperature anomaly reconstruction. Gray lines represent annual reconstruction indices and the black line shows a 10-yr weighted running mean. (b) Wavelet power spectrum of extended tree-ring chronology. Cross-hatched regions represent the cone of influence where zero-padding of the data was used to reduce variance using a Marlet-2 function. Black contours indicate significant modes of variance with a 5% significance level using an autoregressive lag-1 red-noise background spectrum (Torrence and Compo, 1998).

Figure 7. Normalized air-temperature tree-ring reconstruction smoothed with a 25-yr spline. Vertical bars represent the number (50-yr increments) of dated central Coast Mountain Little Ice Age moraines reported by Smith and Desloges (2000), Larocque and Smith (2003) and Harvey and Smith (in press) in accordance with air-temperature trends.

Tree-ring derived Little Ice Age temperature trends from the central British Columbia Coast Mountains, Canada

from ScienceDirect Publication: Quaternary Research

Source:Quaternary Research

Kara J. Pitman, Dan J. Smith

Most glaciers in the British Columbia Coast Mountains reached their maximum Holocene extent during the Little Ice Age. Early- and late-Little Ice Age intervals of expansion and retreat fluctuations describe a mass-balance response to changing climates. Although existing dendroclimatic records provide insights into these climatic fluctuations over the last 400yr, their short durations prohibit evaluation of early-Little Ice Age climate variability. To extend the duration of these records, submerged coarse woody debris salvaged from a high-elevation lake was cross-dated to living chronologies. The resulting chronology provides the opportunity to reconstruct a regional June–July air-temperature anomaly record extending from AD1225 to 2010. The reconstruction shows that the intervals AD1350–1420, 1475–1550, 1625–1700 and 1830–1940 characterized distinct periods of below-average June–July temperature followed by periods of above-average temperature. Our reconstruction provides the first annually resolved insights into high-elevation climates spanning the Little Ice Age in this region and indicates that Little Ice Age moraine stabilization corresponds to persistent intervals of warmer-than-average temperatures. We conclude that coarse woody debris submerged in high-elevation lakes has considerable potential for developing lengthy proxy climate records, and we recommend that researchers focus attention on this largely ignored paleoclimatic archive. 

New paper predicts AGW will cause ~ 12 million more serious crimes in US

A working paper from the Harvard Kennedy School of Government breathlessly predicts 

"Between 2010 and 2099, climate change will cause an additional 30,000 murders, 200,000 cases of rape, 1.4 million aggravated assaults, 2.2 million simple assaults, 400,000 robberies, 3.2 million burglaries, 3.0 million cases of larceny, and 1.3 million cases of vehicle theft in the United States." [11.7 million additional crimes]

The paper fails to note the inconvenient truth that US per-capita property and violent crimes peaked before 1992 and have continuously declined since. Estimated homicide rates in the US have declined by almost 80% over the past 300 years since the Little Ice Age. Obviously, US crime rates are not a function of tiny long-term changes in average US or global temperatures over these time periods. 

Total US Violent & Property crimes 1960-2012. Note: This graph does not account for the large increase in population. 

Property crime rates in the United states per 100,000 population beginning in 1960 above. Violent crime rates in the United states per 100,000 population beginning in 1960 shown below. Source: Bureau of Justice Statistics.Source: Bureau of Justice Statistics.  Images from Wikipedia

The U.S. murder rate (homicides per 1,000 people) over time. Via Andrew Sullivan.

Crime, Weather, and Climate Change

Matthew Ranson 

Abt Associates, Inc.
July 17, 2012

Harvard Kennedy School M-RCBG Associate Working Paper Series No. 8 
Abstract:      
This paper estimates the impact of climate change on the prevalence of criminal activity in the United States. The analysis is based on a 50-year panel of monthly crime and weather data for 2,972 U.S. counties. I identify the effect of weather on monthly crime by using a semi-parametric bin estimator and controlling for county-by-month and county-by-year fixed effects. The results show that temperature has a strong positive effect on criminal behavior, with little evidence of lagged impacts. Between 2010 and 2099, climate change will cause an additional 30,000 murders, 200,000 cases of rape, 1.4 million aggravated assaults, 2.2 million simple assaults, 400,000 robberies, 3.2 million burglaries, 3.0 million cases of larceny, and 1.3 million cases of vehicle theft in the United States.

The full paper is available for download at the link above.

Article in nature says extreme weather events can't currently be attributed to global warming

An editorial published in the current issue of nature notes that "Better models are needed before exceptional events can be reliably linked to global warming."  The article notes, "At a workshop last week in Oxford, UK, convened by the Attribution of Climate-related Events group — a loose coalition of scientists from both sides of the Atlantic — some speakers questioned whether event attribution was possible at all. It currently rests on a comparison of the probability of an observed weather event in the real world with that of the ‘same’ event in a hypothetical world without global warming. One critic argued that, given the insufficient observational data and the coarse and mathematically far-from-perfect climate models used to generate attribution claims, they are unjustifiably speculative, basically unverifiable and better not made at all."

Extreme weather

Better models are needed before exceptional events can be reliably linked to global warming.

19 September 2012  nature

As climate change proceeds — which the record summer melt of Arctic sea-ice suggests it is doing at a worrying pace — nations, communities and individual citizens may begin to seek compensation for losses and damage arising from global warming. Climate scientists should be prepared for their skills one day to be probed in court. Whether there is a legal basis for such claims, such as that brought against the energy company ExxonMobil by the remote Alaskan community of Kivalina, which is facing coastal erosion and flooding as the sea ice retreats, is far from certain, however. So lawyers, insurers and climate negotiators are watching with interest the emerging ability, arising from improvements in climate models, to calculate how anthropogenic global warming will change, or has changed, the probability and magnitude of extreme weather and other climate-related events. But to make this emerging science of ‘climate attribution’ fit to inform legal and societal decisions will require enormous research effort.

Attribution is the attempt to deconstruct the causes of observable weather and to understand the physics of why extremes such as floods and heatwaves occur. This is important basic research. Extreme weather and changing weather patterns — the obvious manifestations of global climate change — do not simply reflect easily identifiable changes in Earth’s energy balance such as a rise in atmospheric temperature. They usually have complex causes, involving anomalies in atmospheric circulation, levels of soil moisture and the like. Solid understanding of these factors is crucial if researchers are to improve the performance of, and confidence in, the climate models on which event attribution and longer-term climate projections depend.

Event attribution is one of the proposed ‘climate services’ — seasonal climate prediction is another — that are intended to provide society with the information needed to manage the risks and costs associated with climate change. Advocates of climate services see them as a counterpart to the daily weather forecast. But without the computing capacity of a well-equipped national meteorological office, heavily model-dependent services such as event attribution and seasonal prediction are unlikely to be as reliable.

“To make this emerging science of ‘climate attribution’ fit to inform legal and societal decisions will require enormous research effort.”

At a workshop last week in Oxford, UK, convened by the Attribution of Climate-related Events group — a loose coalition of scientists from both sides of the Atlantic — some speakers questioned whether event attribution was possible at all. It currently rests on a comparison of the probability of an observed weather event in the real world with that of the ‘same’ event in a hypothetical world without global warming. One critic argued that, given the insufficient observational data and the coarse and mathematically far-from-perfect climate models used to generate attribution claims, they are unjustifiably speculative, basically unverifiable and better not made at all. And even if event attribution were reliable, another speaker added, the notion that it is useful for any section of society is unproven.

Both critics have a point, but their pessimistic conclusion — that climate attribution is a non-starter — is too harsh. It is true that many climate models are currently not fit for that purpose, but they can be improved. Evaluation of how often a climate model produces a good representation of the type of event in question, and whether it does so for the right reasons, must become integral to any attribution exercise. And when communicating their results, scientists must be open about shortcomings in the models used.

It is more difficult to make the case for ‘usefulness’. None of the industry and government experts at the workshop could think of any concrete example in which an attribution might inform business or political decision-making. Especially in poor countries, the losses arising from extreme weather have often as much to do with poverty, poor health and government corruption as with a change in climate. The United Nations is planning to set up a fund with the aim of reducing loss and damage due to climate change, but the complexity of such issues is making negotations difficult.

These caveats do not mean that event attribution is a lost cause. But they are a reminder that designers of climate services must think very clearly about how others might want to use the knowledge that climate scientists produce. That could be a task for social scientists, who have good methods for analysing decision-making and social trans-actions. They need to be more involved in shaping the production and dissemination of climate knowledge.

Nature

 

489,

 

335–336

 

(20 September 2012)

 

doi:10.1038/489335b

Antarctic sea ice reaches record high while IPCC models predicted the opposite

A recent paper in the Journal of Climate finds that most climate models erroneously predict that Antarctic sea ice extent decreased over the past 30 years, which "differs markedly from that observed."  As noted in the abstract, Antarctic sea ice has confounded the models by instead increasing over the satellite era. In fact, it is currently at a record extent that is more than 2 standard deviations above the 1979-2000 average. The authors lament, "The negative [Antarctic sea ice] trends in most of the model runs over 1979 - 2005 are a continuation of an earlier decline, suggesting that the processes responsible for the observed increase over the last 30 years are not being simulated correctly."

Journal of Climate 2012 ; e-View

doi: http://dx.doi.org/10.1175/JCLI-D-12-00068.1

An Initial Assessment of Antarctic Sea Ice Extent in the CMIP5 Models

John Turner, Tom Bracegirdle, Tony Phillips, Gareth J. Marshall, and J. Scott Hosking

British Antarctic Survey, National Environment Research Council, Cambridge, UK

Abstract

We examine the annual cycle and trends in Antarctic sea ice extent (SIE) for 18 Coupled Model Intercomparison Project 5 models that were run with historical forcing for the 1850s to 2005. Many of the models have an annual SIE [sea ice extent] cycle that differs markedly from that observed over the last 30 years. The majority of models have too small a SIE at the minimum in February, while several of the models have less than two thirds of the observed SIE at the September maximum. In contrast to the satellite data, which exhibits a slight increase in SIE, the mean SIE of the models over 1979 - 2005 shows a decrease in each month, with the greatest multi-model mean percentage monthly decline of 13.6% dec^-1 in February and the greatest absolute loss of ice of -0.40 × 10⁶ km² dec^-1 in September. The models have very large differences in SIE over 1860 – 2005. Most of the control runs have statistically significant trends in SIE over their full time span and all the models have a negative trend in SIE since the mid-Nineteenth Century. The negative SIE trends in most of the model runs over 1979 - 2005 are a continuation of an earlier decline, suggesting that the processes responsible for the observed increase over the last 30 years are not being simulated correctly.

New paper shows warming causes decreased extreme weather

From the latest NIPCC Report: 

North Atlantic Storms: Medieval Warm Period vs. Little Ice Age 

In the words of Trouet et al. (2012), "an increasing number of high-resolution proxy records covering the last millennium have become available in recent years, providing an increasingly powerful reference frame for assessing current and future climate conditions," and, as might be added, for assessing the validity of the climate-alarmist claim that warmer conditions typically lead to increases in the frequency and/or ferocity of stormy weather. In the present study, therefore, Trouet et al. searched the scientific literature for evidence pertinent to their climate modeling concern, which also happens to be pertinent to the concern about global warming and what it does or does not imply about concurrent storminess. So what did the search reveal?

Among other things, the three researchers report that (1) "the content of marine-source ssNa aerosols in the GISP2 ice core record, a proxy for storminess over the adjacent ocean through the advection of salt spray [ss], is high during the LIA with a marked transition from reduced levels during the MCA [hereafter MWP] (Meeker and Mayewski, 2002; Dawson et al., 2007)," (2) "the onset of the LIA in NW Europe is notably marked by coastal dune development across western European coastlines linked to very strong winds during storms (Clarke and Rendell, 2009; Hansom and Hall, 2009)" and often inundating local settlements and therefore with supporting archival evidence (Lamb, 1995; Bailey et al., 2001)," (3) "a number of studies of Aeolian sand deposition records from western Denmark exist that have recorded a period of destabilization of coastal sand dunes and sand migration during the LIA and have ascribed it to a combination of increased storminess and sea-level fluctuations (Szkornik et al., 2008; Clemmensen et al., 2001; Aagard et al., 2007)," (4) "similar records and interpretations are available for the British Isles (Hansom and Hall, 2009) and Scotland (Gilbertson et al., 1999; Wilson, 2002)," (5) "in an analysis of Royal Navy ships' log books from the English Channel and southwestern approaches covering the period between 1685 and 1750 CE, Wheeler et al. (2010) note a markedly enhanced gale frequency during one of the coldest episodes of the LIA ... towards the end of the Maunder Minimum [MM]," (6) "this late phase of the MM is also registered by the deflation of sand into the ombrotrophic peat bogs of Store mosse and Undarmosse in southwest Sweden (De Jong et al., 2006)," (7) "more evidence for increased storm severity during the MM is provided by an archive-based reconstruction of storminess over the Northwest Atlantic and the North Sea (Lamb and Frydendahl, 1991)," (8) "increased storm activity during the LIA was not restricted to northwestern Europe, but was also recorded further south along the Atlantic coast in The Netherlands (Jelgersma et al., 1995) and northern (Sorrel et al., 2009) and southwestern France (Clarke et al., 2002)," and (9) "sedimentary records of LIA coastal dune accretion have also been found further south on the French Mediterranean coast (Dezileau et al., 2011) and in the western Iberian Peninsula (Borja et al., 1999; Zazo et al., 2005; Clarke and Rendell, 2006)."

Given such findings, for this particular portion of the planet, it should be very clear that relative coolness, as opposed to relative warmth, typically leads to more extreme storms, which is just the opposite of what the world's climate alarmists continue to contend.

Reference:

Trouet, V., Scourse, J.D. and Raible, C.C. 2012. North Atlantic storminess and Atlantic Meridional Overturning Circulation during the last millennium: Reconciling contradictory proxy records of NAO variability. Global and Planetary Change 84-85: 48-55.

Additional References
Aagaard, T., Orford, J. and Murray, A.S. 2007. Environmental controls on coastal dune formation; Skallingen Spit, Denmark. Geomorphology 83: 29-47.

Bailey, S.D., Wintle, A.G., Duller, G.A.T. and Bristow, C.S. 2001. Sand deposition during the last millennium at Aberffraw, Anglesey, North Wales as determined by OSL dating of quartz. Quaternary Science Reviews 20: 701-704.

Borja, F., Zazo, C., Dabrio, C.J., del Olmo, F.D., Goy, J.L. and Lario, J. 1999. Holocene Aeolian phases and human settlements along the Atlantic coast of southern Spain. The Holocene 9: 333-339.

Clarke, M.L. and Rendell, H.M. 2006. Effects of storminess, sand supply and the North Atlantic oscillation on sand invasion and coastal dune accretion in western Portugal. The Holocene 16: 10.1191/0959683606h1932rp.

Clarke, M.L. and Rendell, H.M. 2009. The impact of North Atlantic storminess on western European coasts: a review. Quaternary International 195: 31-41.

Clarke, M., Rendell, H., Tastet, J.-P., Clave, B. and Masse, L. 2002. Late-Holocene sand invasion and North Atlantic storminess along the Aquitaine Coast, southwest France. The Holocene 12: 231-238.

Clemmensen, L.B., Pye, K., Murray, A. and Heinemeier, J. 2001. Sedimentology, stratigraphy, and landscape evolution of a Holocene coastal dune system, Lodbjerg, NW Jutland, Denmark. Sedimentology 48: 3-27.

Dawson, A.G., Hickey, K., Mayewski, P.A. and Nesje, A. 2007. Greenland (GISP2) ice core and historical indicators of complex North Atlantic climate changes during the fourteenth century. The Holocene 17: 10.1177/0959683607077010.

De Jong, R., Bjorck, S., Bjorkman, L. and Clemmensen, L.B. 2006. Storminess variation during the last 6500 years as reconstructed from an ombrotrophic peat bog in Halland, southwest Sweden. Journal of Quaternary Science 21: 10.1002/jqs.1011.

Dezileau, L., Sabatier, P., Blanchemanche, P., Joly, B., Swingedouw, D., Cassou, C., Castaings, J., Martinez, P. and Von Grafenstein, U. 2011. Intense storm activity during the Little Ice Age on the French Mediterranean coast. Palaeogeography, Palaeoclimatology, Palaeoecology 299: 289-297.

Gilbertson, D.D., Schwenninger, J.L., Kemp, R.A. and Rhodes, E.J. 1999. Sand-drift and soil formation along an exposed North Atlantic coastline: 14,000 years of diverse geomorphological, climatic and human impacts. Journal of Archaeological Science 26: 439-469.

Hansom, J.D. and Hall, A.M. 2009. Magnitude and frequency of extra-tropical North Atlantic cyclones: a chronology from cliff-top storm deposits.Quaternary International 195: 10.1016/j.quaint.2007.11.010.

Jelgersma, S., Stive, M.J.F. and van der Walk, L. 1995. Holocene storm surge signatures in the coastal dunes of the western Netherlands. Marine Geology 125: 95-110.

Lamb, H.H. 1995. Climate, History and the Modern World, Second Edition. Routledge.

Lamb, H.H. and Frydendahl, K. 1991. Historic Storms of the North Sea, British Isles and Northwest Europe. Cambridge University Press, Cambridge, United Kingdom.

Meeker, L.D. and Mayewski, P.A. 2002. A 1400-year high-resolution record of atmospheric circulation over the North Atlantic and Asia. The Holocene 12: 257-266.

Sorrel, P., Tessier, B., Demory, F., Delsinne, N. and Mouaze, D. 2009. Evidence for millennial-scale climatic events in the sedimentary infilling of a macrotidal estuarine system, the Seine estuary (NW France). Quaternary Science Reviews 28: 499-516.

Szkornik, K., Gehrels, W.R. and Murray, A.S. 2008. Aeolian sand movement and relative sea-level rise in Ho Bugt, western Denmark, during the 'Little Ice Age'. The Holocene 18: 10.1177/0959683608091800.

Wheeler, D., Garcia-Herrera, R., Wilkinson, C.W. and Ward, C. 2010. Atmospheric circulation and storminess derived from Royal Navy logbooks: 1685-1750 (vol 101, pg 257, 2010). Climatic Change 103: 10.1007/s10584.009.9755.3.

Wilson, P. 2002. Holocene coastal dune development on the South Erradale peninsula, Wester Ross, Scotland. Scottish Journal of Geology 38: 5-13.

Zazo, C., Mercier, N., Silva, P.G., Dabrio, C.J., Goy, J.L., Roquero, E., Soler, V., Boria, F., Lario, J., Polo, D. and de Luque, L. 2005. Landscape evolution and geodynamic controls in the Gulf of Cadiz (Huelva coast, SW Spain) during the Late Quaternary. Geomorphology 68: 269-290.