"President Obama has announced a series of executive actions to reduce carbon pollution, prepare the U.S. for the impact of climate change and lead international efforts to address global climate change." [here]
This sentence confirms the turn of the U.S. policy on the environment protection issue. It focuses on the carbon pollution, states the condition of climate change (fait accompli) and the necessity for making all the efforts for dealing with the future consequences, and finally raises the U.S. as a leader-country in this "battle".
Implicitly, the information which it conveys, sounds as if there exists a direct relationship between the emission of carbon dioxide and the global climate change, where global climate change stands for global warming [here]
Therefore, by controlling the carbon pollution one would expect the lowering of the global temperature.
Let's see if this assumption is grounded.
1. AIR TEMPERATURE ANOMALY
In the collective unconscious, the environmental scenario in the next decades will be marked by ever growing global temperatures. The currently spread information foresee structural break in the dynamics of the climate.
But what do really the data tell us ?
Figure1 tracks the anomalies of the global near-surface air temperature in the period 1850-2013. The source of data is the HadCRUT4 [download data sets here] which is provided by the Hadley Centre of the UK Meteorological office and the Climatic Research Unit (CRU) of the University of East Anglia.
The term temperature anomaly means a departure from a reference value or long-term average. A positive anomaly indicates that the observed temperature was warmer than the reference value, while a negative anomaly indicates that the observed temperature was cooler than the reference value. Absolute estimates of global average surface temperature are difficult to compile for several reasons. Some regions have few temperature measurement stations (e.g., the Sahara Desert) and interpolation must be made over large, data-sparse regions. In mountainous areas, most observations come from the inhabited valleys, so the effect of elevation on a region’s average temperature must be considered as well. For example, a summer month over an area may be cooler than average, both at a mountain top and in a nearby valley, but the absolute temperatures will be quite different at the two locations. The use of anomalies in this case will show that temperatures for both locations were below average.[See also...]. Since 1979, apart from the 1985 data [2], we note the ramping of the temperature anomaly in the positive area. This roughly marks the beginning of the recent period of global warming, after termination of the previous period of global cooling (from 1940). The red thick line is the three years moving average that shows the stop raising of the curve since 2010.
Some studies [2-4] have reported the positive correlation between the Northern Hemisphere temperature anomaly and the Greenland ice sheet temperature.
Let's see if this assumption is grounded.
1. AIR TEMPERATURE ANOMALY
In the collective unconscious, the environmental scenario in the next decades will be marked by ever growing global temperatures. The currently spread information foresee structural break in the dynamics of the climate.
"A new federal report reveals alarming statistics on climate change. According to the 3rd National Climate Assessment, released in draft form today from the U.S. Global Change Research Program, the world could warm by more than 12°F by the end of the century if action isn’t taken to reduce greenhouse gas emissions. “The evidence is clear and mounting,” said WRI’s president, Andrew Steer, in response to the report. “The United States sits at the center of the climate crisis. Record heat is devastating crops, rivers are drying up, and storms are bearing down on our cities. Climate change is taking its toll on people and their economies, and will only become more intense without a strong and rapid response here in the United States and around the globe. It’s not too late to take action, but given lags in policy and geophysical processes, the window is closing.” - [...See more at]
But what do really the data tell us ?
Figure1 tracks the anomalies of the global near-surface air temperature in the period 1850-2013. The source of data is the HadCRUT4 [download data sets here] which is provided by the Hadley Centre of the UK Meteorological office and the Climatic Research Unit (CRU) of the University of East Anglia.
The Hadley Centre of the UK Meteorological office and the Climatic Research Unit (CRU) of the University of East Anglia have since 1989 jointly maintained a global surface temperature record, HadCRUT. The current version of this record, HadCRUT3, is very widely cited in the academic literature (currently around 900 citations), and provides a record of combined land and ocean temperatures running back to 1850. The dataset is updated monthly to provide a continuous snapshot of the state of the climate.
Recently a new version of the record, HadCRUT4, has been released running to December 2010, with monthly updates planned in future. This update is a response to several factors. [...See more at].
Figure 1. Global near-surface air temperature anomalies (1850-2013). Time series are presented as temperature anomalies (C°) relative to 1961-1990.The term temperature anomaly means a departure from a reference value or long-term average. A positive anomaly indicates that the observed temperature was warmer than the reference value, while a negative anomaly indicates that the observed temperature was cooler than the reference value. Absolute estimates of global average surface temperature are difficult to compile for several reasons. Some regions have few temperature measurement stations (e.g., the Sahara Desert) and interpolation must be made over large, data-sparse regions. In mountainous areas, most observations come from the inhabited valleys, so the effect of elevation on a region’s average temperature must be considered as well. For example, a summer month over an area may be cooler than average, both at a mountain top and in a nearby valley, but the absolute temperatures will be quite different at the two locations. The use of anomalies in this case will show that temperatures for both locations were below average.[See also...]. Since 1979, apart from the 1985 data [2], we note the ramping of the temperature anomaly in the positive area. This roughly marks the beginning of the recent period of global warming, after termination of the previous period of global cooling (from 1940). The red thick line is the three years moving average that shows the stop raising of the curve since 2010.
2. THE GREENLAND ICE SHEET TEMPERATURE vs. THE ATMOSPHERIC CARBON DIOXIDE: THE INDUSTRIAL AGE
Some studies [2-4] have reported the positive correlation between the Northern Hemisphere temperature anomaly and the Greenland ice sheet temperature.
"Climate influences the Greenland ice sheet mass budget which in turns exerts a significant influence on global sea level and thermoaline circulation." [2]
Here the link to the data from the GISP2 project (Greenland Ice Sheet Project) that estimate the temperature across the Holocene Age.
The increased greenhouse is considered as the major responsible for the global and Northern Hemisphere warming in the period 1975-2007, whilst the Northern Hemisphere cooling during 1940-1970 has been attributed to the effect of sulfate aerosol cooling and partly to decreasing solar activity in that period.
During the 1881-2006 period Greenland ice sheet temperature variations are correlated with the Northern Hemisphere anomalies (r=0.658).
The past CO2 atmospheric content comes from the World Data Center for Paleoclimatology and NOAA Paleoclimatology Program: (see Monnin, E., et al. 2004). [5]
The plots of Figure 2 focus on the industrial age (i.e., by the end of the XVIII century).
The left panel draws the air temperature of the Greenland Summit ice sheet as reconstructed by Alley (2000) [6] from the GISP2 data. The right panel describes the evolution of the carbon dioxide content (parts per million, ppm) in the atmosphere in Antarctica [7].
Figure 3. Location of the Greenland Summit Observatory.
The Greenland Environmental Observatory - GEOSummit, [web site link] on the Summit of the Greenland ice sheet (updated coordinates: 72.5796° N, 38.4592° W) at 3216 m above sea level gathers data of the Greenland arctic environment. It was established in 1989 by the Danish Commission for Scientific Research and the US National Science Foundation.
In Figure 4 the same data have been standardized, therefore we can easily observe how they track similar patterns across the considered period
Figure 4. Air Temperature at the Greenland Summit vs. Antarctica Atmospheric CO2 (industrial age): standardized data.
The blue curve represents the temperature data and the red curve the carbon dioxide time series.
Because of the increasing of CO2 in the last 250 years may be directly related to the human industrial activities, Figure 3 seems to support the hypothesis that there exists a close relationship between global warming and CO2 emissions. In the last decades the CO2 level in standard deviation units has showed an exponential growth with respect to the average of the period and the temperature mean deviation seems to follow the same rate of growth as the CO2.
The Bland-Altman plot (Figure 5) allows to analyze those patterns seemingly driven by the CO2 dynamics. The mean between the two standardized times series for each time is reported on the abscissa. The difference between the standardized temperature and the standardized CO2 level is reported on the ordinate axis. Data are spaced out by ten years.
Figure 5. Air temperature variations vs. CO2 variations: Bland-Altman plot (Industrial Age).
Denoting by SD the standard deviation of the difference between the standardized time series, we can trace in the plot the green shaded area, at ±1.96SD around the mean difference (d = -0.02072). This area corresponds to the "neutral" range where the differences (bias) between the two standardized time series are not significant. The points falling outside the green area are to be considered outliers.
All the points apart from the one representing the present time (the red dot), fall in the neutral area. So, the last decade would be characterized by the reversal of the downward trend signed by the previous ten decades. The anomaly stands out from the fact that in the last decade the deviation of the temperature from its average over the whole period of 250 years is significantly greater than the increasing deviation of the CO2 emission from its average in the same period. Hence, the temperature would have overreacted to the increasing CO2 emission. This results seems to be consistent with the theory according to which the crossing of some threshold in the CO2 emission would cause change points in the dynamics of the global temperature. Structural changes in the climate dynamics are known as
tipping points whose effects impact at a rate and intensity greater than the changes currently being observed in the climate system.
Professor James E. Hansen (Department of Earth and Environmental Sciences at the Columbia University, New York) asserts that 350 parts per million (ppm) is the upper limit of CO2 concentration in the atmosphere, therefore a tipping point has already been reached in 2008 (385ppm) [here the paper].
2. THE GREENLAND ICE SHEET TEMPERATURE vs. THE ATMOSPHERIC CARBON DIOXIDE UNDER ANOTHER PERSPECTIVE: FAR IN THE PAST. THE HOLOCENE EPOCH.
It is worth pointing out that in the previous interglacial periods the global temperature had been higher on average (from 1 C° to 3 C°) than in the present.
Figure 7. Temperature at the Greenland Summit ice sheet: Holocene Epoch.
During the first 2000 years of the Holocene epoch the temperature passed from -48C° to -32C° and afterwards it has remained into the range -32C° : -28.7C°. The minimum value of the industrial age (-32C°) measured at the end of the Little Ice Age, lines up with the absolute minimum of the period up to 10000 years before present. Neither the current maximum temperature of -29.25C° can be considered abnormal ! In fact, similar values are likely to have occurred 2070 years ago [Julius Caesar conquered Lusitania for the glory of Rome, in Syria the Seluecid empire came to an end, in China the Han dynasty kept the control of the Western Regions], 3200 years ago [collapse of the Hittite empire], and so on... We can also observe relative long intervals where the temperature remained above the present upper limit [from 3320 to 3200, from 6990 to 6800, from 7980 to 7690 years before present].
Let's now analyze the interval of the last 10000 years before present.
The time series of the air temperature in that period results nonstationary with mean -30.61C° and standard deviation 0.7574.
Detrended Fluctuation Analysis (DFA) is a method for determining self-similarity of nonstationary time series. DFA is able to reveal the extent of the long range temporal correlation (LRTC) in time series [9].
Figure 8. Antarctica Atmospheric CO2 (Holocene Epoch)
The unprecedent abrupt shift of the atmospheric CO2 then is not reflected (directly or entirely) in the variation of the air temperature (Figures 9-11)
Figure 9. Air Temperature at the Greenland Summit vs. Antarctica Atmospheric CO2 (Age before present: from -10000 to 0): standardized data.
The plot of the standardized values of temperature (C°) and carbon dioxide concentration (ppm) reveals the huge departure of the two time series starting from the last recent decades. Unlike the visualisation of Figure 4, the analysis in the long run provides a different perspective in the relationship between CO2 level and temperature as represented also in Figure 10. The present deviation of the temperature from its 10000 years' mean is within a normal range therefore its increase in the last centuries would not be explained by the anomalies of the CO2 emission over the industrial age.
Figure 10. Air temperature variations vs. CO2 variations: Bland-Altman plot (Holocene Epoch)
The difference-mean plot of Figure 10 shows a clear downward trend in the data. All the anomalies are counted since the year 1880 and they all fall in the negative sector, i.e., the growth of the CO2 concentration over the last 130 years goes beyond the variation of the temperature at an abnormal rate. We can observe that the rate of change of the anomalous differences has increased since the last three decades. To spotlight this "acceleration" we measure the (euclidean) distance between the successive outliers of Figure 10 which is reported in the ordinate axis of Figure 11. In the abscissa there are the corresponding years before present.
Figure 11. Anomalies in differences between temperature and CO2 emission in the last 130 years.
The dynamics of the anomalous differences observed in the last 130 years resulted uniform until 30 years ago. The next sudden jumps in the pattern of the anomalies are ascribable to the abnormal increases of the CO2 values.
3. CONCLUSIONS
The assessments on climate variations seem to depend on the extent of the temporal window to which we refer. The question is whether the anomalies recorded over periods of few decades or few centuries, may enable us to infer structural change in climate.
Long term analysis sheds light on some topics:
The increased greenhouse is considered as the major responsible for the global and Northern Hemisphere warming in the period 1975-2007, whilst the Northern Hemisphere cooling during 1940-1970 has been attributed to the effect of sulfate aerosol cooling and partly to decreasing solar activity in that period.
During the 1881-2006 period Greenland ice sheet temperature variations are correlated with the Northern Hemisphere anomalies (r=0.658).
The past CO2 atmospheric content comes from the World Data Center for Paleoclimatology and NOAA Paleoclimatology Program: (see Monnin, E., et al. 2004). [5]
[here the data]: EPICA Dome C Ice Core High Resolution Holocene and Transition CO2 Data.
Data from 1950 up to present have been filled with the updated records.
Figure2. Air Temperature at the Greenland Summit vs. Antarctica Atmospheric CO2 (industrial age).
The plots of Figure 2 focus on the industrial age (i.e., by the end of the XVIII century).
The left panel draws the air temperature of the Greenland Summit ice sheet as reconstructed by Alley (2000) [6] from the GISP2 data. The right panel describes the evolution of the carbon dioxide content (parts per million, ppm) in the atmosphere in Antarctica [7].
Figure 3. Location of the Greenland Summit Observatory.
In Figure 4 the same data have been standardized, therefore we can easily observe how they track similar patterns across the considered period
Figure 4. Air Temperature at the Greenland Summit vs. Antarctica Atmospheric CO2 (industrial age): standardized data.
Because of the increasing of CO2 in the last 250 years may be directly related to the human industrial activities, Figure 3 seems to support the hypothesis that there exists a close relationship between global warming and CO2 emissions. In the last decades the CO2 level in standard deviation units has showed an exponential growth with respect to the average of the period and the temperature mean deviation seems to follow the same rate of growth as the CO2.
The Bland-Altman plot (Figure 5) allows to analyze those patterns seemingly driven by the CO2 dynamics. The mean between the two standardized times series for each time is reported on the abscissa. The difference between the standardized temperature and the standardized CO2 level is reported on the ordinate axis. Data are spaced out by ten years.
Figure 5. Air temperature variations vs. CO2 variations: Bland-Altman plot (Industrial Age).
Denoting by SD the standard deviation of the difference between the standardized time series, we can trace in the plot the green shaded area, at ±1.96SD around the mean difference (d = -0.02072). This area corresponds to the "neutral" range where the differences (bias) between the two standardized time series are not significant. The points falling outside the green area are to be considered outliers.
All the points apart from the one representing the present time (the red dot), fall in the neutral area. So, the last decade would be characterized by the reversal of the downward trend signed by the previous ten decades. The anomaly stands out from the fact that in the last decade the deviation of the temperature from its average over the whole period of 250 years is significantly greater than the increasing deviation of the CO2 emission from its average in the same period. Hence, the temperature would have overreacted to the increasing CO2 emission. This results seems to be consistent with the theory according to which the crossing of some threshold in the CO2 emission would cause change points in the dynamics of the global temperature. Structural changes in the climate dynamics are known as
tipping points whose effects impact at a rate and intensity greater than the changes currently being observed in the climate system.
"A tipping point occurs when the climate system is forced to cross some threshold, triggering a translation to a new state at a rate determined by the climate system itself and faster than the cause." [8]
Professor James E. Hansen (Department of Earth and Environmental Sciences at the Columbia University, New York) asserts that 350 parts per million (ppm) is the upper limit of CO2 concentration in the atmosphere, therefore a tipping point has already been reached in 2008 (385ppm) [here the paper].
2. THE GREENLAND ICE SHEET TEMPERATURE vs. THE ATMOSPHERIC CARBON DIOXIDE UNDER ANOTHER PERSPECTIVE: FAR IN THE PAST. THE HOLOCENE EPOCH.
All the considerations on the climate variations that we have seen up to now are based on a temporal refererence of at most 250 years. This period would correspond to about 10 generations, which is a relatively long interval from a human point of view. But it is absolutely insufficient for explaining possible tipping points in the climate, whilst oscillations and large variations and succession of glacial and interglacial periods may be observed across the eras.
Figure 6. Global temperature anomaly over the ages.
Source: the Vostok Ice Core Data [download here].
Figure 6. Global temperature anomaly over the ages.
Source: the Vostok Ice Core Data [download here].
 |
The plot shows the global temperature over the last 422000 years as differences from the modern average temperature (the horizontal dotted line). Glacial eras had occurred around every 100000 years and the last ice age ended around 11000 years ago. The current interglacial period is called Holocene epoch (that is pointed out in the red rectangle).
|
It is worth pointing out that in the previous interglacial periods the global temperature had been higher on average (from 1 C° to 3 C°) than in the present.
Figure 7. Temperature at the Greenland Summit ice sheet: Holocene Epoch.
 |
| The time course of the air temperature over the Holocene epoch estimated from the Greenland Summit ice sheet data. A relatively fast jump of the temperature characterized the beginning of the period as consequence of the recover from the previous ice age. The coloured areas represent the historical ages from 3000 B.C. to the fall of the Roman Empire (green), from 476 A.C. to 1760 A.C. (yellow), industrial age from 1760 up to present (gray). The horizontal dotted lines correspond to the average temperature range over the industrial age. |
During the first 2000 years of the Holocene epoch the temperature passed from -48C° to -32C° and afterwards it has remained into the range -32C° : -28.7C°. The minimum value of the industrial age (-32C°) measured at the end of the Little Ice Age, lines up with the absolute minimum of the period up to 10000 years before present. Neither the current maximum temperature of -29.25C° can be considered abnormal ! In fact, similar values are likely to have occurred 2070 years ago [Julius Caesar conquered Lusitania for the glory of Rome, in Syria the Seluecid empire came to an end, in China the Han dynasty kept the control of the Western Regions], 3200 years ago [collapse of the Hittite empire], and so on... We can also observe relative long intervals where the temperature remained above the present upper limit [from 3320 to 3200, from 6990 to 6800, from 7980 to 7690 years before present].
Let's now analyze the interval of the last 10000 years before present.
The time series of the air temperature in that period results nonstationary with mean -30.61C° and standard deviation 0.7574.
Detrended Fluctuation Analysis (DFA) is a method for determining self-similarity of nonstationary time series. DFA is able to reveal the extent of the long range temporal correlation (LRTC) in time series [9].
Specifically, if a time series has a non-random temporal structure with slowly decaying autocorrelations, DFA measures the decaying time by estimating an opportune power law exponent alpha. The correspondence between the autocorrelation structure and the exponent alpha is usually defined as follows:
Uncorrelated sequence alpha~0.5
Anti-correlated sequence 0<alpha<0.5
Long range temporal correlation 0.5<alpha<1
Strong correlation but not from a power law alpha>1
DFA applied to the 10000 years data series, returns a coefficient alpha = 0.6769 therefore we may assume the presence of LRTC.
That is, the system is "self-organizing" and so, except for some fairly slow stochastic drive, most of the fluctuations are endogenous rather than being determined by strong external causes.
Hence, even though in the very last decades the carbon dioxide emissions have grown at exponential rate (Figure 8), the DFA result softens the alleged direct effects of CO2 pollution on the variations of the air temperature. Figure 8. Antarctica Atmospheric CO2 (Holocene Epoch)
The unprecedent abrupt shift of the atmospheric CO2 then is not reflected (directly or entirely) in the variation of the air temperature (Figures 9-11)
Figure 9. Air Temperature at the Greenland Summit vs. Antarctica Atmospheric CO2 (Age before present: from -10000 to 0): standardized data.
The plot of the standardized values of temperature (C°) and carbon dioxide concentration (ppm) reveals the huge departure of the two time series starting from the last recent decades. Unlike the visualisation of Figure 4, the analysis in the long run provides a different perspective in the relationship between CO2 level and temperature as represented also in Figure 10. The present deviation of the temperature from its 10000 years' mean is within a normal range therefore its increase in the last centuries would not be explained by the anomalies of the CO2 emission over the industrial age.
Figure 10. Air temperature variations vs. CO2 variations: Bland-Altman plot (Holocene Epoch)
The difference-mean plot of Figure 10 shows a clear downward trend in the data. All the anomalies are counted since the year 1880 and they all fall in the negative sector, i.e., the growth of the CO2 concentration over the last 130 years goes beyond the variation of the temperature at an abnormal rate. We can observe that the rate of change of the anomalous differences has increased since the last three decades. To spotlight this "acceleration" we measure the (euclidean) distance between the successive outliers of Figure 10 which is reported in the ordinate axis of Figure 11. In the abscissa there are the corresponding years before present.
Figure 11. Anomalies in differences between temperature and CO2 emission in the last 130 years.
3. CONCLUSIONS
The assessments on climate variations seem to depend on the extent of the temporal window to which we refer. The question is whether the anomalies recorded over periods of few decades or few centuries, may enable us to infer structural change in climate.
Long term analysis sheds light on some topics:
- The current global temperature is not the absolute maximum looking back in past. Similar or greater values would have occurred also during the not industrialized epochs.
- The control of the CO2 emission, specifically the limitation of the fossil fuel in the human activities is a positive measure for the enviromental sake. But if the purpose of cutting the CO2 emission is to stop the global warming, then we should expect to miss the target.
- Maybe, it is someway comforting the idea that we can "switch" off the global temperature by modulating the fossil fuel consumption. This anthropocentric perspective may deceive our decisions, because we can not rule the climate, but only adapt to it. Therefore, if we have deteriorated the climate equilibrium, then because of the chaotic dynamics of the system we can not go back and correct mistakes. In that case we will pay the consequences.
- Moreover, the relationship between CO2 and air temperature is not so direct as we could imagine. Anyway, if we are nearby (if not we have already gone beyond) a tipping point, then even large reductions in the CO2 emission might not suffice for recovering climate equilibrium.
- According to the studies [10-11] of the russian physicist H. Abdussamatof reported in a previous post [here], there is the possibility that we are going to face a period of global cooling, because the Sun is entering a phase of Grande Minimum of its irradiation activities. This counter-current hypothesis is worth to be investigated further.
1 In December 2009, President Obama and other world
leaders came together to negotiate the Copenhagen Accord, an important
milestone in which, for the first time, all major developed and developing
economies agreed to implement measures to limit their greenhouse gas emissions
and to do so in an internationally transparent manner. In 2010, the Cancun
Agreement confirmed and substantially extended the core elements of the
Copenhagen Accord in the areas of finance, technology and adaptation as well as
mitigation and transparency in an instrument that the Parties enthusiastically
endorsed.
In December 2011 at Durban, the United States and the international community took important steps to make operational all of the key elements of the Cancun agreement, including a transparency regime to monitor and review mitigation efforts by developed and developing countries, as well as established a Green Climate Fund. In addition, a process was launched to negotiate a new legal instrument to take effect from 2020, andU.S.
2 Box, J.E., Yang, L., Bromwich, D.H. and Bau, L.-S. 2009. Greenland Ice Sheet Surface Air Temperature Variability: 1840–2007. Journal of Climate 22, 4029-4049.
3 Chylek, P., Folland, C.K., Lesins, G. and Manvendra, K.D. 2010. Twentieth century bipolar seesaw of the Arctic and Antarctic surface air temperatures. Geophysical Research Letters, 37, L08703, doi: 10.1029/2010GL042793.
4 Alley, R.B. 2003. Palaeoclimatic insights into future climate challenges. Phil. Trans. R. Soc. Lond. A 2003, 361, 1831-1849.
5 Monnin, E., E.J. Steig, U. Siegenthaler, K. Kawamura, J. Schwander, B. Stauffer, T.F. Stocker, D.L. Morse, J.-M. Barnola, B. Bellier, D. Raynaud, and H. Fischer. 2004. Evidence for substantial accumulation rate variability in Antarctica during the Holocene, through synchronization of CO2 in the Taylor Dome, Dome C and DML ice cores. Earth and Planetary Science Letters, 224, 45-54, doi: 10.1016/j.epsl.2004.05.007.
6 Alley, R.B. 2000. The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19, 213-226.
In December 2011 at Durban, the United States and the international community took important steps to make operational all of the key elements of the Cancun agreement, including a transparency regime to monitor and review mitigation efforts by developed and developing countries, as well as established a Green Climate Fund. In addition, a process was launched to negotiate a new legal instrument to take effect from 2020, and
2 Box, J.E., Yang, L., Bromwich, D.H. and Bau, L.-S. 2009. Greenland Ice Sheet Surface Air Temperature Variability: 1840–2007. Journal of Climate 22, 4029-4049.
3 Chylek, P., Folland, C.K., Lesins, G. and Manvendra, K.D. 2010. Twentieth century bipolar seesaw of the Arctic and Antarctic surface air temperatures. Geophysical Research Letters, 37, L08703, doi: 10.1029/2010GL042793.
4 Alley, R.B. 2003. Palaeoclimatic insights into future climate challenges. Phil. Trans. R. Soc. Lond. A 2003, 361, 1831-1849.
5 Monnin, E., E.J. Steig, U. Siegenthaler, K. Kawamura, J. Schwander, B. Stauffer, T.F. Stocker, D.L. Morse, J.-M. Barnola, B. Bellier, D. Raynaud, and H. Fischer. 2004. Evidence for substantial accumulation rate variability in Antarctica during the Holocene, through synchronization of CO2 in the Taylor Dome, Dome C and DML ice cores. Earth and Planetary Science Letters, 224, 45-54, doi: 10.1016/j.epsl.2004.05.007.
6 Alley, R.B. 2000. The Younger Dryas cold interval as viewed from central Greenland. Quaternary Science Reviews 19, 213-226.
7 Core locations: EPICA Dome C: 75° 06'S, 123° 21'E Dronning Maud Land (DML): 75° 00'S, 00° 04'E Taylor Dome: 77° 47'47" S, 158° 43'26" E
8 Alley, R. B., J. Marotzke, W. Nordaus, J. Overpeck, D. Peteet, R. P. Jr., R. Pierrehumbert,
P. Rhines, T. Stocker, L. Talley, J. Wallace, A. Isern, J. Dandelski, C. Elfring, M. Gopnik,
M. Kelly, J. Bachim, and A. Carlisle (2002). Abrupt Climate Change: Inevitable Surprises.
Washington, DC: National Research Council, National Academy Press.
9 Peng C-K, Buldyrev SV, Havlin S, Simons M, Stanley HE, Goldberger AL. Mosaic organization of DNA nucleotides. Phys Rev E 1994;49:1685-1689.
8 Alley, R. B., J. Marotzke, W. Nordaus, J. Overpeck, D. Peteet, R. P. Jr., R. Pierrehumbert,
P. Rhines, T. Stocker, L. Talley, J. Wallace, A. Isern, J. Dandelski, C. Elfring, M. Gopnik,
M. Kelly, J. Bachim, and A. Carlisle (2002). Abrupt Climate Change: Inevitable Surprises.
Washington, DC: National Research Council, National Academy Press.
9 Peng C-K, Buldyrev SV, Havlin S, Simons M, Stanley HE, Goldberger AL. Mosaic organization of DNA nucleotides. Phys Rev E 1994;49:1685-1689.
10 H.I. Abdussamatov,(2013). Grand Minimum of the Total Solar
Irradiance Leads to the Little Ice Age, J Geol Geosci 2013 2:
113
11 H.I. Abdussamatov,(2013). Bicentennial decrease of the
total solar irradiance leads to unbalanced thermal budget of the Earth and the
Little Ice Age. Applied Physics Research, vol 4(1): 178-184.
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