+Myth: The Tropospheric Hot Spot is a Fingerprint of CO2-induced Warming

This post is part of a series addressing issues related to the hot spot. The other parts of this series are listed in the "Myths about the Hot Spot" section of the "Quick Scientific Debunking" page.


The outline for this post is as follows:

1. The Myth and Its Flaw
2. Context and Analysis
3. Posts Providing Further Information and Analysis
4. References

This is the "+References" version of this post, which means that this post contains my full list of references and citations. If you would like an abbreviated and easier to read version, then please go to the "main version" of this post.

References are cited as follows: "[#]", with "#" corresponding to the reference number given in the References section at the end of this post.

The following twitter thread summarizes some of the main points in this blogpost: https://twitter.com/AtomsksSanakan/status/954013475470299136

1.  The Myth and Its Flaw

Climate models predict that in moist tropical areas, a region of the lower atmosphere will warm more than Earth's surface [10; 25, page 4; 26, from 31:01 to 31:48; 27 - 30; 81, pages 7 and 8; 82, pages 101 and 102; 102, section 3.4 on page 762; 114]. This region of greater warming is known as the "hot spot" [8; 16, pages 14 and 42; 33, page 6; 68; 114]. The myth states that the hot spot is a specific sign, or fingerprint, of anthropogenic (human-caused) carbon-dioxide-induced global warming.

Proponents of this myth include David Evans [1 - 7; 57; 64; 138], Stefan Molyneux [7], Judith Curry [8; 87], Richard Lindzen [9, page 942; 142, page 7], S. Fred Singer [10; 76], Nicola Scafetta [98, appendix Y on page 53; 101, pages 3, 27 - 32, and 34 - 39], Christopher Monckton [10; 11; 165], Anthony Watts [12], John Christy [13 - 17; 106; 110], Roy Spencer [101, pages 3, 27 - 32, and 34 - 39], Roger Pielke Sr. [15], Craig Idso [101, pages 3, 27 - 32, and 34 - 39], Joseph D'Aleo [16; 17; 101, pages 3, 27 - 32, and 34 - 39], James Wallace III [16; 17; 101, pages 3, 27 - 32, and 34 - 39], Steve McIntyre [18], Ross McKitrick [92, citing 93 or 94; 106; 141], William Happer [101, pages 3, 27 - 32, and 34 - 39], Tim Ball [101, pages 3, 27 - 32, and 34 - 39], Don Easterbrook [101, pages 3, 27 - 32, and 34 - 39], Anthony Lupo [101, pages 3, 27 - 32, and 34 - 39], Luboš Motl [153; 154], the "lukewarmer" [88] Lucia Liljegren [89], The Daily Caller [19], Paul Homewood [20], Tom Nelson [21], Vladan Ducić [63], and a number of blogs including WattsUpWithThat [22 - 24].

Christy, D'Aleo, Wallace III [16; 17], and an organization known as ICECAP [75], use the myth to attack the US Environmental Protection Agency's attempts to regulate carbon dioxide (CO2) emissions.

The myth's flaw: the hot spot is not a fingerprint for attributing global warming to increased CO2, since the hot spot occurs with any sufficiently large surface warming in the tropics, especially warming of the tropical oceans [27, page 383]. The scientific community has known this since at least 1975 [81, page 7; 99, figure 6 on page 71; 139, page 2048]. This conclusion is supported by climate models [36, figure 12.a on page 707; 52; 53; 78 - 80; 85; 86; 91 as taken from 90; 96; 100, figure 1; 102, section 3.4 on page 762; 111, figure 10; 112, plate 3 on page 6838; 113, figure 20 on page 28; 139, figure 3b and page 2048], an understanding of the mechanism via which the hot spot forms [27, pages 383 and 384; 31; 32; 65; 66; 84; 86; 139, page 2048; 156], and observations of the hot spot forming in response to short-term non-CO2-induced warming [27, page 384; 53; 58; 59, figures 3c, 4a, and 4b; 60; 61, page 102; 62, figure 4; 67, figures 1 and 3; 69, figure 4; 77; 80; 83, figure 3; 96; 97; 107, figures 2 and 3; 108, figure 1; 109, figure 4; 157, figure 2a; 163, figure 2].

2. Context and Analysis

Earth's atmosphere contains multiple layers. The layer closest to the Earth's surface air is known as the troposphere. Above the troposphere is the stratosphere. Tropospheric temperature decreases with increasing height; the rate of decrease is known as the tropospheric lapse rate.

Climate models and basic physical theory predict that warming at Earth's surface will cause more water to evaporate, especially over tropical oceans. This evaporation increases the amount of water vapor in the air, since warmer air can hold more water vapor. The vapor-rich air then rises by convection. The water vapor subsequently condenses with increasing tropospheric height, since tropospheric temperature and pressure decreases with increasing height.

Condensation of water vapor releases some of the energy that went into evaporating the water; this energy release causes further warming. So water vapor condensation causes more warming of the lower troposphere and even more warming of the upper troposphere. This shrinks the rate at which tropospheric temperature decreases with increasing height, thereby reducing the magnitude of the tropospheric lapse rate [10; 25, page 4; 26, from 31:01 to 31:48; 27 - 30; 81, pages 7 and 8; 82, pages 101 and 102; 114; 139, page 2048; 156; 163], as depicted in figure 1:

Figure 1: A diagram of tropical tropospheric warming reducing the magnitude of the tropospheric lapse rate (adapted from Crok, Strengers, and Verheggen [33, page 3], though originally taken from a climate science textbook [166]). The horizontal dimension represents temperature, with temperature increasing as one goes from left to right. The vertical dimension represents altitude in the troposphere, with altitude increasing as one goes further up from Earth's surface at the black line. The blue line represents the tropical temperature profile before warming, while the red line represents the tropical temperature profile after warming. Water vapor condensation causes more warming with increasing height [10; 25, page 4; 26, from 31:01 to 31:48; 27 - 30; 81, pages 7 and 8; 82, pages 101 and 102; 114; 139, page 2048; 163], leading to the red line being steeper than the blue line. As a result, there is less of a temperature decrease with increasing height after tropical warming. Thus the lapse rate's magnitude is greater for the blue line than for the red line, indicative of a lapse rate reduction in response to tropical warming.

To borrow an analogy from the climate researcher Mark Richardson [114, from 3:05 to 3:49]: this energy transfer from the near-surface to higher in the troposphere is similar to sweating, in which sweat evaporates on a person's skin and then condenses elsewhere, cooling the skin and transferring body heat to the site of condensation. Thus the tropical troposphere will behave like a moist adiabat, in which the rate of warming increases with increasing height in response to water vapor condensing from water-vapor-saturated, moist air [10; 25, page 4; 26, from 31:01 to 31:48; 27 - 30; 81, pages 7 and 8; 82, pages 101 and 102; 114; 139, page 2048; 163]. So this amplified tropospheric warming has more to do with heat released by condensing water vapor (also known as release of latent heat), and less to do with CO2 emitting radiation into the atmosphere [31; 32; 65; 66; 84; 156; 163]. 

CO2-induced warming can occur without this tropospheric amplification, particularly in areas that behave quite unlike a moist adiabat. For instance, increased CO2 causes surface warming in the Arctic [115 - 123; 164] and deserts [70 - 74; 164]. Yet these regions lack both tropospheric amplification in the upper troposphere [26, from 29:38 to 31:01; 70 - 72; 124 - 126; 145 - 150, using 143, as per 144] and amplification of warming with increasing elevation [127 - 129]. This makes sense since these regions are dissimilar to a moist adiabat, consistent with climate model results and basic physic theory [26, from 29:38 to 31:01; 35, page 375; 81; 82; 130 - 134; 135, page 445; 151; 152].

It is at this point that the myth comes in. The aforementioned tropical amplification is called the tropical tropospheric hot spot by many myth proponents [8; 16, pages 14 and 42; 33, page 6; 68]. Myth defenders claim the hot spot is expected to be a sign/fingerprint of global warming caused by CO2 [1 - 24; 57; 63; 64; 76; 87; 89; 92, citing 93 or 94; 98, appendix Y on page 53; 101, pages 3, 27 - 32, and 34 - 39; 106; 110; 138; 141]. Many myth proponents support this claim by (intentionally or unintentionally) misrepresenting [1; 2; 5; 6; 11; 12; 20 - 22; 89; 141] the following 2007 figure made by the United Nations Intergovernmental Panel on Climate Change (IPCC):

Figure 2: Atmospheric temperature change in K/century from 1890 to 1999 in the PCM (Parallel Climate Model) in response to (a) increased solar forcing (from increased solar output), (b) volcanic activity, (c) well-mixed greenhouse gases such as CO2, (d) tropospheric and stratosopheric ozone changes, (e) sulfate aerosols, and (f) the sum of all the aforementioned factors. Darker blues represent cooling and darker reds represent warming. The horizontal axis indicates latitude, with the tropics being between roughly 30°N and 30°S. The vertical axis indicates altitude, with decreasing atmospheric pressure as altitude increases [35, page 675]. The tropical troposphere lies below 150hPa, while the tropical stratosphere is above 70hPa [34]. Tropical tropospheric warming increases with height in panel f, indicative of the hot spot. This figure is taken from a 2007 report of the United Nations Intergovernmental Panel on Climate Change (IPCC) [35, page 675].

A number of myth proponents claim that since the hot spot most clearly appears in the greenhouse gas portion of figure 2, then the hot spot is a specific sign of greenhouse-gas-induced (and thus CO2-induced) global warming [1; 2; 5; 6; 11; 12; 20 - 22; 89]. Yet myth defenders are wrong on this point; the hot spot in figure 2 is not specific to CO2-induced warming. Instead, the pronounced hot spot appears in the CO2 portion of the figure because CO2 levels increased enough that CO2 caused most of the recent global warming. If instead solar output increased enough to cause most of the recent global warming, then there would be a pronounced hot spot in the solar portion of the figure 2. This is made clear in figure 3 below, which comes from an earlier 2001 IPCC report:

Figure 3: ECHAM3/LSG model (European Center/Hamburg Model 3 / Large Scale Geostrophic coupled atmosphere-ocean climate model) simulation of the atmospheric response to (a) increased solar forcing (from increased solar output) and (b) increased CO2 forcing (from increased CO2 levels). Colored areas indicate significant responses, with darker blues indicating cooling and darker reds indicating warming. The horizontal axis represents latitude, with the tropics being between roughly 30°N and 30°S. The vertical axis represents altitude, with decreasing atmospheric pressure as altitude increases [36, page 707]. The tropical troposphere lies below 150hPa, while the tropical stratosphere is above 70hPa [34]. Tropical tropospheric warming increases with height in both panels a and b, indicating that the hot spot forms in response to both solar-induced warming and CO2-induced warming. In contrast, strong tropical stratospheric cooling comes with CO2-induced warming, but not solar-induced warming. This figure is taken from a 2001 report of the United Nations Intergovernmental Panel on Climate Change (IPCC) [36, page 707]; the report took the image from a 1997 paper [102, figure 5a].

Figure 2a illustrates this point as well. In figure 2a, bright yellow appears in the tropics (30N to 30S) at around 250hPa, in contrast to the greenish-yellow in the tropics at around 1000hPa. Thus increased solar output results in more tropical upper tropospheric warming than tropical near-surface warming, indicative of a hot spot [35, page 675; 114]. So climate models (including models used by the IPCC) show a hot spot in response to solar-induced surface warming [36, figure 12.a on page 707; 52; 53; 78 - 80; 85; 86; 91 as taken from 90; 96; 100, figure 1; 102, section 3.4 on page 762; 111, figure 10; 112, plate 3 on page 6838; 113, figure 20 on page 28; 139, figure 3b and page 2048].

This model-based result addresses whether or not the hot spot is a fingerprint of CO2-induced global warming. Fingerprints distinguish one cause of warming from another cause of warming, as noted by the IPCC [35, page 703; 36, section 12.4.2.1 on page 718; 140, page 894]. For example, strong stratospheric cooling is a fingerprint that occurs with CO2-induced warming [35, pages 674 and 675; 36 - 45], while increased solar output would not account for most of the observed stratospheric cooling [35, page 674; 39 - 41; 44; 46 - 53] (see figures 2 and 3 above). Scientists have observed this, and other, fingerprints of CO2-induced warming, as I discuss in "Myth: The Sun Caused Recent Global Warming and the Tropical Stratosphere Warmed" and "Myth: Attributing Warming to CO2 Involves the Fallaciously Inferring Causation from a Mere Correlation". Some individuals called this pattern of stratospheric cooling with tropospheric warming [158] a piece of "smoking gun" evidence of CO2-induced human-caused climate change [159, page 34; 160, pages 16 - 17; 161, page 1; 162, chapter 2]. Unfortunately, the myth proponent Judith Curry [8; 87] misrepresents this statement by claiming that it was the tropospheric hot spot that was meant to be the smoking gun [87].

In contrast to strong stratospheric cooling, the hot spot is not a fingerprint for causal attribution of warming, since the hot spot occurs with any large warming of Earth's surface in the tropics (especially warming of the ocean surface) [27; 33, pages 7 - 9], as long as the warming triggers the latent heat release discussed above. For instance, a hot spot forms in response to short-term surface warming that is not caused by CO2 [27, page 384; 53; 58; 59, figures 3c, 4a, and 4b; 60; 61, page 102; 62, figure 4; 67, figures 1 and 3; 69, figure 4; 77; 80; 83, figure 3; 96; 97; 107, figures 2 and 3; 108, figure 1; 109, figure 4; 157, figure 2a; 163, figure 2]. The following source makes this clear, as do others [110; 114]:

"In the tropics, moist thermodynamic processes amplify surface warming [...]. Such tropical amplification occurs for any surface warming; it is not a unique signature of greenhouse gas (GHG)-induced warming, as has been incorrectly claimed (Christy 2015) [27, page 383]."

Ben Santer, the lead author of this quote [27], was also the lead author for the research [155] used to make the IPCC image shown in figure 2. He also served as the contributing author to the chapter in which figure 2 appeared [35]. So given Santer's aforementioned words and his involvement with figure 2, figure 2 most likely was not meant to show that the hot spot is a fingerprint that distinguishes CO2 from other causes of warming.

Other portions of the IPCC's report fit with this assessment. For example, the IPCC cites research on short-term hot spot formation in response to non-CO2-induced warming [35, section 9.4.4.4 on page 701; 95, section 8.6.3.1.1 on page 635; the cited research includes 96 and 97]. The IPCC cites this research in the same 2007 report from which figure 2 was taken [35, section 9.4.4.4 on page 701; 95, section 8.6.3.1.1 on page 635]. In fact, on the page before figure 2, the IPCC cites [37, page 674] the 1997 source [102, figure 5a] of figure 3 when discussing the atmospheric response to increased solar output. Thus it makes no sense to claim that the solar-induced hot spot in the 2001 figure 3 remains incompatible with the 2007 IPCC report from which figure 2 is taken.

And in this 2007 report, the IPCC also states that lapse rate reduction occurs because the tropical atmosphere behaves somewhat like a moist adiabat [95, section 8.6.3.1.1 on page 635]. So even in the 2007 report many myth proponents misrepresent [1; 2; 5; 6; 11; 12; 20 - 22; 89], the IPCC acknowledges that tropical tropospheric amplification also occurs in response to non-CO2-induced warming due to the tropics behaving somewhat like a moist adiabat. This is consistent with the solar-induced hot spot depicted in figure 3 above from an earlier 2001 IPCC report.

Moreover, since at least 1975 the scientific community has known that warming from increased solar radiation would cause the hot spot [139, figure 3b and page 2048], and known the moist adiabatic basis of the hot spot [81, page 7; 99, figure 6 on page 71; 139, page 2048]. As Manabe and Wetherald note in their seminal 1975 paper on model-based projection of solar-induced global warming:

"In lower latitudes of the model, the warming is greater in the upper troposphere (~336 mb) than near the surface. Qualitatively, the same feature was present in Fig. 4b of MW75 ["MW75" is a 1975 paper that presented a model-based projection of CO2-induced warming [81]] and results from the predominance of moist convection which adjusts temperatures in a vertical column toward the moist adiabatic lapse rate. Since the moist adiabatic lapse rate decreases with increasing temperature, the temperature of the upper troposphere increases more than that of the lower troposphere in lower latitudes where moist convection predominates [139, page 2048]."

Myth advocates are therefore decades behind on the relevant science. Thus myth proponents, not the IPCC, bear the blame for myth proponents misrepresenting [1; 2; 5; 6; 11; 12; 20 - 22; 89] the IPCC's 2007 figure as being support for the proponents' myth.

Even Roy Spencer, a research colleague of myth proponent John Christy, mentions the convection-based hot spot mechanism discussed above [68]. He also admits that the hot spot is not a fingerprint of CO2-induced warming [54] (Spencer also contradicts himself by saying it is a fingerprint [101, pages 3, 27 - 32, and 34 - 39], that there are not any fingerprints [54; 103], and that greenhouse gases cause stratospheric cooling [104; 105]), though Spencer does not get much else right with respect to climate science.

Thus the hot spot is not very useful for distinguishing different causes of warming. A number of myth proponents acknowledge this point and accept that CO2-independent warming mechanisms would also cause the hot spot (ex: Evans [1, pages 12 - 14; 64], Lindzen [55, page 18; 142, page 7], Christy [33, pages 7 - 9 and 20; 56; 106, page 532; 136, section 3.5], and Curry [8, 2nd comment; 137]). Yet these proponents defend the myth anyway, even though the myth contradicts basic physics [27, pages 383 and 384; 31; 32; 65; 66; 84; 86; 139, page 2048; 156], their own position, the climate models they cite [36, figure 12.a on page 707; 52; 53; 78 - 80; 85; 86; 91 as taken from 90; 96; 100, figure 1; 102, section 3.4 on page 762; 111, figure 10; 112, plate 3 on page 6838; 113, figure 20 on page 28; 139, figure 3b and page 2048], and observations of a hot spot from short-term non-CO2-induced warming [27, page 384; 53; 58; 59, figures 3c, 4a, and 4b; 60; 61, page 102; 62, figure 4; 67, figures 1 and 3; 69, figure 4; 77; 80; 83, figure 3; 96; 97; 107, figures 2 and 3; 108, figure 1; 109, figure 4; 157, figure 2a; 163, figure 2]. Oh well.

(In "John Christy and Atmospheric Temperature Trends", I discuss other examples of the myth proponent John Christy misrepresenting climate science in politically expedient ways)

3. Posts Providing Further Information and Analysis

• Sections 3.1, 3.2, and 3.4 of part 1 "John Christy and the Tropical Tropospheric Hot Spot"
• "Myth: The Tropospheric Hot Spot does not Exist"

4. References

1. David Evans': "The Missing Hotspot"
2. http://joannenova.com.au/2012/05/models-get-the-core-assumptions-wrong-the-hot-spot-is-missing/
3. https://chriscolose.wordpress.com/2008/12/20/skepticsdenialists-part-2-hotspots-and-repetition/
4. https://bravenewclimate.com/2008/08/10/dr-david-evans-born-again-alarmist/
5. http://naturalclimatechange.us/disproofs-of-agw-hypothesis/the-missing-hotspot-2/
6. "The missing greenhouse signature"
7. Stefan Molyneux's video: "Climate Change in 12 Minutes - The Skeptic's Case"
8. https://judithcurry.com/2015/03/04/differential-temperature-trends-at-the-surface-and-in-the-lower-atmosphere/
9. "Taking greenhouse warming seriously"
10. https://www.skepticalscience.com/tropospheric-hot-spot-advanced.htm
11. "Greenhouse warming? What Greenhouse warming?"
12. https://wattsupwiththat.com/2014/08/04/what-stratospheric-hotspot/
13. "McNider and Christy: Why Kerry is flat wrong on climate change"
14. https://ourchangingclimate.wordpress.com/2014/02/22/john-christy-richard-mcnider-roy-spencer-flat-earth-hot-spot-figure-baseline/
15. "What do observational datasets say about modeled tropospheric temperature trends since 1979?"
16. "On the Existence of a “Tropical Hot Spot" & The Validity of EPA’s CO2 Endangerment Finding"
17. "On the Existence of a “Tropical Hot Spot” & The Validity of EPA’s CO2 Endangerment Finding, Abridged Research Report, Second Edition"
18. https://climateaudit.org/2008/04/26/tropical-troposphere/
19. "The ‘fingerprint’ of global warming doesn’t exist in the real world, study finds"
20. https://notalotofpeopleknowthat.wordpress.com/2015/09/13/another-attempt-to-find-the-tropical-hotspot/
21. http://hockeyschtick.blogspot.com/2010/07/why-agw-hot-spot-wont-happen.html
22. https://wattsupwiththat.com/2017/04/02/why-john-christies-missing-hotspot-matters/
23. http://www.c3headlines.com/2013/02/ipccs-global-warming-hypothesis-fails-ultimate-test-no-tropical-hotspot-after-17-years-of-immense-co.html
24. http://www.c3headlines.com/2014/01/ipcc-fail-tropical-hotspot-refuted-by-latest-empirical-evidence-those-stubborn-facts.html
25. "Response of the large-scale structure of the atmosphere to global warming"
26. Ray Pierrehumbert's 2012 video: "Tyndall Lecture: GC43I. Successful Predictions - 2012 AGU Fall Meeting"
27. "Comparing tropospheric warming in climate models and satellite data"
28. "Physical mechanisms of tropical climate feedbacks investigated using temperature and moisture trends"
29. "Regional variation of the tropical water vapor and lapse rate feedbacks"
30. "Elevation-dependent warming in mountain regions of the world"
31. "Anthropogenic weakening of the tropical circulation: The relative roles of direct CO2 forcing and sea surface temperature change"
32. "Quantifying contributions of climate feedbacks to tropospheric warming in the NCAR CCSM3.0"
33. "Extended Summary of the Climate Dialogue on the (missing) tropical hot spot"
34. "Tropical Tropopause Layer" [doi:10.1029/2008RG000267]
35. "Climate change 2007: The physical science basis; Chapter 9: Understanding and attributing climate change"
36. "Climate change 2001: The scientific basis; Chapter 12: Detection of climate change and attribution of causes"
37. "Isolating the roles of different forcing agents in global stratospheric temperature changes using model integrations with incrementally added single forcings"
38. "Stratospheric ozone change and related climate impacts over 1850–2100 as modelled by the ACCMIP ensemble"
39. "Attributing the forced components of observed stratospheric temperature variability to external drivers"
40. "Identifying human influences on atmospheric temperature"
41. "Human and natural influences on the changing thermal structure of the atmosphere"
42. "Towards a physical understanding of stratospheric cooling under global warming through a process-based decomposition method"
43. "Models versus radiosondes in the free atmosphere: A new detection and attribution analysis of temperature"
44. "Executive summary: Temperature trends in the lower atmosphere - Understanding and reconciling differences"
45. "Use of SSU/MSU satellite observations to validate upper atmospheric temperature trends in CMIP5 simulations"
46. "Comment on “Climate Science and the Uncertainty Monster” by J. A. Curry and P. J. Webster"
47. "Is the Sun causing global warming?"
48. "Stratospheric temperature trends over 1979–2015 derived from combined SSU, MLS, and SABER satellite observations"
49. "Stratospheric temperature changes during the satellite era"
50. "Spectrally dependent CLARREO infrared spectrometer calibration requirement for climate change detection"
51. "On the detection of the solar signal in the tropical stratosphere"
52. "Robustness of dynamical feedbacks from radiative forcing: 2% solar versus 2× CO2 experiments in an idealized GCM"
53. "Observed tropospheric temperature response to 11-yr solar cycle and what it reveals about mechanisms"
54. http://www.drroyspencer.com/2009/10/hotspots-and-fingerprints/
55. "Global warming: How to approach the science; by Richard S. Lindzen, Program in Atmospheres, Oceans, and Climate; Massachusetts Institute of Technology; November 17, 2010; Testimony: House Subcommittee on Science and Technology"
56. http://www.climatedialogue.org/the-missing-tropical-hot-spot/#comment-754
57. https://climatism.wordpress.com/2014/01/28/the-missing-hot-spot/
58. "Interaction of the recent 50 year SST trend and La Niña 2010: amplification of the Southern Annular Mode and Australian springtime rainfall"
59. "Internal variability in simulated and observed tropical tropospheric temperature trends"
60. "Influence of changes in observations on precipitation: A case study for the Climate Forecast System Reanalysis (CFSR)"
61. "Effect of recent minor volcanic eruptions on temperatures in the upper troposphere and lower stratosphere"
62. "ENSO‐related moisture and temperature anomalies over South America derived from GPS radio occultation profiles"
63. "Temperature altitude amplification as a footprint of a possible anthropogenic impact on the climate of Australia"
64. http://joannenova.com.au/2012/04/so-is-the-hotspot-a-fingerprint-or-signature-is-it-unique/
65. "Relationships between outgoing longwave radiation and diabatic heating in reanalyses"
66. "Large differences in reanalyses of diabatic heating in the tropical upper troposphere and lower stratosphere"
67. "Atmospheric climate change detection by radio occultation data using a fingerprinting method"
68. http://www.drroyspencer.com/2015/05/new-satellite-upper-troposphere-product-still-no-tropical-hotspot/
69. "Tropical temperature variability and Kelvin-wave activity in the UTLS from GPS RO measurements"
70. "Observational evidence for desert amplification using multiple satellite datasets"
71. "Detection and analysis of an amplified warming of the Sahara Desert"
72. "Desert amplification in a warming climate"
73. "Mechanisms for stronger warming over drier ecoregions observed since 1979"
74. "Stronger warming amplification over drier ecoregions observed since 1979"
75. http://icecap.us/images/uploads/ImportanceoftheHotSpot_093016_.pdf
76. "Lack of consistency between modeled and observed temperature trends"
77. "The vertical structure of temperature in the tropics: Different flavors of El Nino"
78. "Why must a solar forcing be larger than a CO2 forcing to cause the same global mean surface temperature change?"
79. "Exploring the stratospheric/tropospheric response to solar forcing"
80. "Patterns of tropospheric response to solar variability"
81. "The effects of doubling the CO2 concentration on the climate of a general circulation model"
82. "On the distribution of climate change resulting from an increase in CO2 content of the atmosphere"
83. "Climate variability and relationships between top-of-atmosphere radiation and temperatures on Earth"
84. "The diabatic heat budget of the upper troposphere and lower/mid stratosphere in ECMWF reanalyses"
85. "Common warming pattern emerges irrespective of forcing location"
86. "The impact of multidecadal Atlantic meridional overturning circulation variations on the Southern Ocean"
87. https://judithcurry.com/2018/01/03/manufacturing-consensus-the-early-history-of-the-ipcc/ [http://archive.is/qDr3v#selection-707.0-707.209]
88. http://rankexploits.com/musings/2015/lukewarmers-in-the-public-eye/
89. http://rankexploits.com/musings/2008/who-expects-a-tropical-tropospheric-hot-spot-from-any-and-all-sources-of-warming/
90. https://data.giss.nasa.gov/efficacy/#table3
91. https://data.giss.nasa.gov/cgi-bin/cdrar/effjk.cgi?xx=efficacy&type=Rc&mod=E2so2&quantity=01&mean_gen=ANN&pscale=1&nobanner=0
92. http://rankexploits.com/musings/2009/new-threat-on-tt-hotspot/#comment-8310
93. http://www.financialpost.com/story.html?id=d84e4100-44e4-4b96-940a-c7861a7e19ad&p=1 (relevant quote: "Second, climate models predict that, if greenhouse gases are driving climate change, there will be a unique fingerprint in the form of a strong warming trend in the tropical troposphere, the region of the atmosphere up to 15 kilometres in altitude, over the tropics [...]. The Intergovernmental Panel on Climate Change (IPCC) states that this will be an early and strong signal of anthropogenic warming. Climate changes due to solar variability or other natural factors will not yield this pattern: only sustained greenhouse warming will do it.")
94. http://www.canada.com/nationalpost/financialpost/comment/story.html?id=d84e4100-44e4-4b96-940a-c7861a7e19ad&p=1
95. "Climate change 2007: The physical science basis; Chapter 8: Climate models and their evaluation"
96. "Amplification of surface temperature trends and variability in the tropical atmosphere"
97. "Influence of patterns of climate variability on the difference between satellite and surface temperature trends"
98. "Climate change and its causes: A discussion about some key issues"
99. "Tropospheric temperature trends: history of an ongoing controversy"
100. "Consistency and discrepancy in the atmospheric response to Arctic sea-ice loss across climate models"
101. USCA Case #09-1322, Document #1312291
102. "Simulation of the influence of solar radiation variations on the global climate with an ocean-atmosphere general circulation model"
103. http://www.drroyspencer.com/2009/04/some-global-warming-qa-to-consider-in-light-of-the-epa-ruling/
104. http://www.drroyspencer.com/2014/04/skeptical-arguments-that-dont-hold-water/
105. http://www.drroyspencer.com/2011/12/why-atmospheric-pressure-cannot-explain-the-elevated-surface-temperature-of-the-earth/
106. "A test of the tropical 200-300 hPa warming rate in climate models"
107. "Water‐vapor climate feedback inferred from climate fluctuations, 2003–2008"
108. "Atmospheric QBO and ENSO indices with high vertical resolution from GNSS radio occultation temperature measurements"
109. "ENSO-related moisture and temperature anomalies over South America derived from GPS radio occultation profiles"
110. https://twitter.com/AndrewDessler/status/437999679494582272
111. "An examination of climate sensitivity for idealized climate change experiments in an intermediate general circulation model"
112. "Radiative forcing and climate response" [DOI: 10.1029/96JD03436]
113. "Efficacy of climate forcings" [DOI: 10.1029/2005JD005776]
114. Mark Richardson's 2015 video: "UQx DENIAL101x 3.4.1.1 Structure of the atmosphere"
115. "Human influence on Arctic sea ice detectable from early 1990s onwards"
116. "One hundred years of Arctic surface temperature variation due to anthropogenic influence"
117. "Attribution of Arctic temperature change to greenhouse-gas and aerosol influences"
118. "Arctic sea ice loss directly follows cumulative anthropogenic CO2 emissions"
119. "Attribution of polar warming to human influence"
120. "Changing state of Arctic sea ice across all seasons"
121. "The trajectory towards a seasonally ice-free Arctic Ocean"
122. "Observations reveal external driver for Arctic sea-ice retreat"
123. "Recent and future changes in Arctic sea ice simulated by the HadCM3 AOGCM"
124. "The central role of diminishing sea ice in recent Arctic temperature amplification"
125. "Amplified Arctic warming and mid-latitude weather: new perspectives on emerging connections"
126. http://images.remss.com/msu/msu_time_series.html
127. "Negative elevation-dependent warming trend in the Eastern Alps"
128. "Evidence of high-elevation amplification versus Arctic amplification"
129. "Regional air pollution brightening reverses the greenhouse gases induced warming-elevation relationship"
130. "Arctic amplification dominated by temperature feedbacks in contemporary climate models"
131. "Sensitivity of a global climate model to an increase of CO2 concentration in the atmosphere"
132. "High-latitude climate change in a global coupled ocean-atmosphere-sea ice model with increased atmospheric CO2"
133. "Processes and impacts of Arctic amplification: A research synthesis"
134. "The atmospheric response to three decades of observed Arctic sea ice loss"
135. "Water vapor feedback and global warming"
136. "Examination of space-based bulk atmospheric temperatures used in climate research"
137. https://climateaudit.org/2008/04/26/tropical-troposphere/#comment-145218
138. http://joannenova.com.au/2008/10/the-missing-hotspot/ (http://archive.is/xTJxL)
139. "The effects of changing the solar constant on the climate of a general circulation model"
140. "Climate change 2013: The physical science basis; Chapter 10: Detection and attribution of climate change: from global to regional"
141. https://climateaudit.org/2008/04/26/tropical-troposphere/#comment-145255 (http://archive.is/qBFzq)
142. http://icecap.us/images/uploads/Global_Warming_and_the_Irrelevance_of_Science-Erice-mod1.pdf
143. "Web-based Reanalysis Intercomparison Tool: Monthly/seasonal time series" https://www.esrl.noaa.gov/psd/cgi-bin/data/testdap/timeseries.pl
144. "Web-Based Reanalysis Intercomparison Tools (WRIT) for analysis and comparison of reanalyses and other datasets"
145. https://www.esrl.noaa.gov/psd/cgi-bin/data/testdap/timeseries.proc.pl?dataset1=ERA-Interim&dataset2=ERA-Interim&var=Air+Temperature&level=300mb&pgT1Sel=10&pgtTitle1=&pgtPath1=&var2=2m+Air+Temperature&level2=1000mb&pgT2Sel=10&pgtTitle2=&pgtPath2=&fyear=1979&fyear2=2018&season=1&fmonth=0&fmonth2=11&type=1&climo1yr1=1981&climo1yr2=2010&climo2yr1=1981&climo2yr2=2010&xlat1=70&xlat2=90&xlon1=0&xlon2=360&maskx=0&zlat1=70&zlat2=90&zlon1=0&zlon2=360&maskx2=0&map=on&yaxis=0&bar=0&smooth=0&runmean=1&yrange1=0&yrange2=0&y2range1=0&y2range2=0&xrange1=0&xrange2=0&markers=0&legend=0&ywave1=&ywave2=&cwavelow=&cwavehigh=&cwaveint=&coi=0&Submit=Create+Plot
146. https://www.esrl.noaa.gov/psd/cgi-bin/data/testdap/timeseries.proc.pl?dataset1=JRA-55&dataset2=JRA-55&var=Air+Temperature&level=300mb&pgT1Sel=10&pgtTitle1=&pgtPath1=&var2=2m+Air+Temperature&level2=1000mb&pgT2Sel=10&pgtTitle2=&pgtPath2=&fyear=1979&fyear2=2018&season=1&fmonth=0&fmonth2=11&type=1&climo1yr1=1981&climo1yr2=2010&climo2yr1=1981&climo2yr2=2010&xlat1=70&xlat2=90&xlon1=0&xlon2=360&maskx=0&zlat1=70&zlat2=90&zlon1=0&zlon2=360&maskx2=0&map=on&yaxis=0&bar=0&smooth=0&runmean=1&yrange1=0&yrange2=0&y2range1=0&y2range2=0&xrange1=0&xrange2=0&markers=0&legend=0&ywave1=&ywave2=&cwavelow=&cwavehigh=&cwaveint=&coi=0&Submit=Create+Plot
147. https://www.esrl.noaa.gov/psd/cgi-bin/data/testdap/timeseries.proc.pl?dataset1=MERRA-2&dataset2=MERRA-2&var=Air+Temperature&level=300mb&pgT1Sel=10&pgtTitle1=&pgtPath1=&var2=2m+Air+Temperature&level2=1000mb&pgT2Sel=10&pgtTitle2=&pgtPath2=&fyear=1979&fyear2=2018&season=1&fmonth=0&fmonth2=11&type=1&climo1yr1=1981&climo1yr2=2010&climo2yr1=1981&climo2yr2=2010&xlat1=70&xlat2=90&xlon1=0&xlon2=360&maskx=0&zlat1=70&zlat2=90&zlon1=0&zlon2=360&maskx2=0&map=on&yaxis=0&bar=0&smooth=0&runmean=1&yrange1=0&yrange2=0&y2range1=0&y2range2=0&xrange1=0&xrange2=0&markers=0&legend=0&ywave1=&ywave2=&cwavelow=&cwavehigh=&cwaveint=&coi=0&Submit=Create+Plot
148. https://www.esrl.noaa.gov/psd/cgi-bin/data/testdap/timeseries.proc.pl?dataset1=NCEP%2FDOE+R2&dataset2=NCEP%2FDOE+R2&var=Air+Temperature&level=300mb&pgT1Sel=10&pgtTitle1=&pgtPath1=&var2=2m+Air+Temperature&level2=1000mb&pgT2Sel=10&pgtTitle2=&pgtPath2=&fyear=1979&fyear2=2018&season=1&fmonth=0&fmonth2=11&type=1&climo1yr1=1981&climo1yr2=2010&climo2yr1=1981&climo2yr2=2010&xlat1=70&xlat2=90&xlon1=0&xlon2=360&maskx=0&zlat1=70&zlat2=90&zlon1=0&zlon2=360&maskx2=0&map=on&yaxis=0&bar=0&smooth=0&runmean=1&yrange1=0&yrange2=0&y2range1=0&y2range2=0&xrange1=0&xrange2=0&markers=0&legend=0&ywave1=&ywave2=&cwavelow=&cwavehigh=&cwaveint=&coi=0&Submit=Create+Plot
149. https://www.esrl.noaa.gov/psd/cgi-bin/data/testdap/timeseries.proc.pl?dataset1=NCEP%2FCFSR&dataset2=NCEP%2FCFSR&var=Air+Temperature&level=300mb&pgT1Sel=10&pgtTitle1=&pgtPath1=&var2=2m+Air+Temperature&level2=1000mb&pgT2Sel=10&pgtTitle2=&pgtPath2=&fyear=1979&fyear2=2018&season=1&fmonth=0&fmonth2=11&type=1&climo1yr1=1981&climo1yr2=2010&climo2yr1=1981&climo2yr2=2010&xlat1=70&xlat2=90&xlon1=0&xlon2=360&maskx=0&zlat1=70&zlat2=90&zlon1=0&zlon2=360&maskx2=0&map=on&yaxis=0&bar=0&smooth=0&runmean=1&yrange1=0&yrange2=0&y2range1=0&y2range2=0&xrange1=0&xrange2=0&markers=0&legend=0&ywave1=&ywave2=&cwavelow=&cwavehigh=&cwaveint=&coi=0&Submit=Create+Plot
150. https://www.esrl.noaa.gov/psd/cgi-bin/data/testdap/timeseries.proc.pl?dataset1=20th+Century+Reanalysis+V2&dataset2=20th+Century+Reanalysis+V2&var=Air+Temperature&level=300mb&pgT1Sel=10&pgtTitle1=&pgtPath1=&var2=2m+Air+Temperature&level2=1000mb&pgT2Sel=10&pgtTitle2=&pgtPath2=&fyear=1979&fyear2=2018&season=1&fmonth=0&fmonth2=11&type=1&climo1yr1=1981&climo1yr2=2010&climo2yr1=1981&climo2yr2=2010&xlat1=70&xlat2=90&xlon1=0&xlon2=360&maskx=0&zlat1=70&zlat2=90&zlon1=0&zlon2=360&maskx2=0&map=on&yaxis=0&bar=0&smooth=0&runmean=1&yrange1=0&yrange2=0&y2range1=0&y2range2=0&xrange1=0&xrange2=0&markers=0&legend=0&ywave1=&ywave2=&cwavelow=&cwavehigh=&cwaveint=&coi=0&Submit=Create+Plot
151. "A decomposition of feedback contributions to polar warming amplification"
152. "How well do we understand and evaluate climate change feedback processes?"
153. https://motls.blogspot.com/2007/08/greenhouse-warming-wrong-altitude-and.html
154. https://motls.blogspot.com/2011/02/why-dana1981-hasnt-proved-climate.html
155. "Contributions of anthropogenic and natural forcing to recent tropopause height changes"
156. "Detection and attribution of upper-tropospheric warming over the tropical western Pacific"
157. "Interdecadal change of the middle‐upper tropospheric land‐sea thermal contrast in the late 1990s and the associated Northern Hemisphere hydroclimate"
158. "A search for human influences on the thermal structure of the atmosphere" (1995 PCMDI report no. 27 for the paper: https://www.osti.gov/servlets/purl/116649)
159. "Sky-high findings drop new hints of greenhouse warming"
160. "The hockey stick and the climate wars: Dispatches from the front lines"
161. "Climate change detection: A review of techniques and applications"
162. "Boiling point: How politicians, big oil and coal, journalists, and activists have fueled a climate crisis - And what we can do to avert disaster"
163. "Explaining differences between recent model and satellite tropospheric warming rates with tropical SSTs"
164. "Process-based decomposition of the decadal climate difference between 2002–13 and 1984–95"
165. https://www.aps.org/units/fps/newsletters/200807/monckton.cfm ["Climate sensitivity reconsidered" ; http://archive.is/Ke8h#selection-2241.0-2303.429]
166. http://www.climate.be/textbook/chapter4_node7.html ("4.2.1 Water vapour and lapse rate feedbacks" ; http://archive.is/AK2Ug)