Changes

In 1861, Irish scientist John Tyndall measured the absorption of radiant energy by various gases in the atmosphere. He concluded that water vapor was the gas primarily responsible. It could therefore be considered the warming agent that Fourier hypothesized. Tyndall suggested that changes in humidity could bring about climate change.

In 1861, Irish scientist John Tyndall measured the absorption of radiant energy by various gases in the atmosphere. He concluded that water vapor was the gas primarily responsible. It could therefore be considered the warming agent that Fourier hypothesized. Tyndall suggested that changes in humidity could bring about climate change.

The AGW theory was first presented in 1896 in an article by Swedish scientist Svante Arrhenius. Arrhenius predicted that a doubling of CO₂ in the atmosphere due to fossil fuel burning would lead to a temperature increase of 3 to 4 °C (about 5 to 7 °F) after 500 years. Arrhenius attributes his misunderstanding of the science to Fourier: "Fourier maintained that the atmosphere acts like the glass of a hothouse."<ref>Arrhenius, Svante, "On the Influence of Carbonic Acid in the Air on the Temperature on the Ground", ''London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science,'' April 1896. Reprinted in ''The Warming Papers'', pp. 56-77.</ref>

The AGW theory was first presented in 1896 in an article by Swedish scientist Svante Arrhenius. Arrhenius predicted that a doubling of CO₂ in the atmosphere due to fossil fuel burning would lead to a temperature increase of 3 to 4&nbsp;°C (about 5 to 7&nbsp;°F) after 500 years. Arrhenius attributes his misunderstanding of the science to Fourier: "Fourier maintained that the atmosphere acts like the glass of a hothouse."<ref>Arrhenius, Svante, "On the Influence of Carbonic Acid in the Air on the Temperature on the Ground", ''London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science,'' April 1896. Reprinted in ''The Warming Papers'', pp. 56-77.</ref>

The use of the Swedish word ''drivbänk'' (hothouse) by Arrhenius and his colleagues is likely to be the origin of the phrase "greenhouse effect." This phrase is first recorded in English in 1907.<ref>"[http://www.easterbrook.ca/steve/2015/08/who-first-coined-the-term-greenhouse-effect/ Who first coined the term “Greenhouse Effect”?]," ''Serendipity,'' August 2015</ref>

The use of the Swedish word ''drivbänk'' (hothouse) by Arrhenius and his colleagues is likely to be the origin of the phrase "greenhouse effect." This phrase is first recorded in English in 1907.<ref>"[http://www.easterbrook.ca/steve/2015/08/who-first-coined-the-term-greenhouse-effect/ Who first coined the term “Greenhouse Effect”?]," ''Serendipity,'' August 2015</ref>

By portraying carbon dioxide as a doomsday chemical, Sagan put a radically new spin on the issue. Both Arrhenius and Callendar had assumed that greenhouse warming would be beneficial. With Rachel Carson's ''Silent Spring'' (1962), Paul R. Ehrlich's ''The Population Bomb'' (1968), and the Club of Rome's ''The Limits to Growth'' (1972), this was an era when the reading public had an enormous appetite for spurious theories concerning human-initiated global catastrophe.

By portraying carbon dioxide as a doomsday chemical, Sagan put a radically new spin on the issue. Both Arrhenius and Callendar had assumed that greenhouse warming would be beneficial. With Rachel Carson's ''Silent Spring'' (1962), Paul R. Ehrlich's ''The Population Bomb'' (1968), and the Club of Rome's ''The Limits to Growth'' (1972), this was an era when the reading public had an enormous appetite for spurious theories concerning human-initiated global catastrophe.

While the Venus discoveries ignited a burst of interest in AGW, they did nothing to shore up its scientific merits. In 1971, Russian climatologist Mikhail Budyko gave a speech to a large international conference in Leningrad in which he presented an alarmist AGW scenario. Reaction was strongly negative. It was clear that AGW was very much a minority opinion among scientists at this time. A quick look at Venus reveals that the atmosphere is opaque due to globe-spanning sulfur dioxide clouds. These clouds are 30 to 40 km thick. No sunlight reaches the surface.<ref>NASA's "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html Venus Fact Sheet]" gives the planet's diurnal temperature range as zero, i.e. no difference between night and day on the surface.</ref> It follows that the planet has no greenhouse effect whatsoever.

While the Venus discoveries ignited a burst of interest in AGW, they did nothing to shore up its scientific merits. In 1971, Russian climatologist Mikhail Budyko gave a speech to a large international conference in Leningrad in which he presented an alarmist AGW scenario. Reaction was strongly negative. It was clear that AGW was very much a minority opinion among scientists at this time. A quick look at Venus reveals that the atmosphere is opaque due to globe-spanning sulfur dioxide clouds. These clouds are 30 to 40&nbsp;km thick. No sunlight reaches the surface.<ref>NASA's "[http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html Venus Fact Sheet]" gives the planet's diurnal temperature range as zero, i.e. no difference between night and day on the surface.</ref> It follows that the planet has no greenhouse effect whatsoever.

In a runaway greenhouse, the greenhouse effect vaporizes additional water, which in turn increases the greenhouse effect. This leads to even more water vaporization and so on in a cycle of positive feedback. Venus has very little water of any kind, so Sagan's runaway greenhouse is not possible.<ref name=pierre>*Raymond T. Pierrehumbert, ''[https://books.google.ca/books?id=bO_U8f5pVR8C&source=gbs_navlinks_s Principles of Planetary Climate]'', pp. 14-15.</br>*Anthony Watts explains why Sagan's theory is "beyond absurd" in "[https://wattsupwiththat.com/2010/05/06/hyperventilating-on-venus/ Hyperventilating on Venus]," May 6, 2010.</ref> Whatever the chemistry of the Venusian atmosphere, water vapor absorbs a wider spectrum of radiation than carbon dioxide does and remains the primary greenhouse gas in the terrestrial atmosphere, as Tyndall showed long ago.

In a runaway greenhouse, the greenhouse effect vaporizes additional water, which in turn increases the greenhouse effect. This leads to even more water vaporization and so on in a cycle of positive feedback. Venus has very little water of any kind, so Sagan's runaway greenhouse is not possible.<ref name=pierre>*Raymond T. Pierrehumbert, ''[https://books.google.ca/books?id=bO_U8f5pVR8C&source=gbs_navlinks_s Principles of Planetary Climate]'', pp. 14-15.<br />*Anthony Watts explains why Sagan's theory is "beyond absurd" in "[https://wattsupwiththat.com/2010/05/06/hyperventilating-on-venus/ Hyperventilating on Venus]," May 6, 2010.</ref> Whatever the chemistry of the Venusian atmosphere, water vapor absorbs a wider spectrum of radiation than carbon dioxide does and remains the primary greenhouse gas in the terrestrial atmosphere, as Tyndall showed long ago.

Venus research proved to be an incubator for AGW showboaters. James “Boiling Oceans” Hansen, who emerged as the public face of AGW in the late 1980s, was a NASA Venus researcher in the 1960s. Overlooking Hansen's history of following one kook theory after another, the mainstream media treated his talk of "runaway greenhouse" and "Venus syndrome" as serious science.<ref>Sullivan, John, "[https://johnosullivan.wordpress.com/2012/05/20/top-scientists-vent-on-nasas-sub-prime-greenhouse-gas-hoaxere-optional/ Top Scientists Vent on NASA’s Sub Prime Greenhouse Gas Hoaxer]", May 20, 2012. "The oceans will begin to boil," Hansen announces in [https://wattsupwiththat.com/2012/01/12/quote-of-the-week-dr-james-hansen-of-nasa-giss-unhinged/ this video]. In his book, ''Storms of my Grandchildren'', Hansen writes: "[I]f we burn all reserves of oil, gas, and coal, there is a substantial chance we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome is a dead certainty."</ref>

Venus research proved to be an incubator for AGW showboaters. James “Boiling Oceans” Hansen, who emerged as the public face of AGW in the late 1980s, was a NASA Venus researcher in the 1960s. Overlooking Hansen's history of following one kook theory after another, the mainstream media treated his talk of "runaway greenhouse" and "Venus syndrome" as serious science.<ref>Sullivan, John, "[https://johnosullivan.wordpress.com/2012/05/20/top-scientists-vent-on-nasas-sub-prime-greenhouse-gas-hoaxere-optional/ Top Scientists Vent on NASA’s Sub Prime Greenhouse Gas Hoaxer]", May 20, 2012. "The oceans will begin to boil," Hansen announces in [https://wattsupwiththat.com/2012/01/12/quote-of-the-week-dr-james-hansen-of-nasa-giss-unhinged/ this video]. In his book, ''Storms of my Grandchildren'', Hansen writes: "[I]f we burn all reserves of oil, gas, and coal, there is a substantial chance we will initiate the runaway greenhouse. If we also burn the tar sands and tar shale, I believe the Venus syndrome is a dead certainty."</ref>

==The temperature record==

==The temperature record==

Global temperatures are tracked by three methods: satellites, weather balloons, and weather stations. All three methods confirm a modest amount of warming in recent decades. Satellite data shows a warming trend of 0.11 K/decade for 1978 to 2015.<ref>Roy W. Spencer, John R. Christy, and William D. Braswell, "[http://www.drroyspencer.com/wp-content/uploads/Version-61.pdf Version 6.0 of the UAH Temperature Dataset Released]", 28 April, 2015.</ref> Weather balloon data shows a warming trend of 0.18 K/decade for 1970 to 2015.<ref>The figure given is for RATPAC-A, surface to 700 mb. See "[https://wattsupwiththat.com/2015/12/14/gavins-admission-about-the-satellite-record-versus-the-surface-temperature-record/ Gavin’s admission about the satellite record versus the surface temperature record]," ''Watt's Up With That''. You can find a collection of global climate charts [https://wattsupwiththat.com/global-climate/ here].</ref>

Global temperatures are tracked by three methods: satellites, weather balloons, and weather stations. All three methods confirm a modest amount of warming in recent decades. Satellite data shows a warming trend of 0.11 K/decade for 1978 to 2015.<ref>Roy W. Spencer, John R. Christy, and William D. Braswell, "[http://www.drroyspencer.com/wp-content/uploads/Version-61.pdf Version 6.0 of the UAH Temperature Dataset Released]", 28 April 2015.</ref> Weather balloon data shows a warming trend of 0.18 K/decade for 1970 to 2015.<ref>The figure given is for RATPAC-A, surface to 700 mb. See "[https://wattsupwiththat.com/2015/12/14/gavins-admission-about-the-satellite-record-versus-the-surface-temperature-record/ Gavin’s admission about the satellite record versus the surface temperature record]," ''Watt's Up With That''. You can find a collection of global climate charts [https://wattsupwiththat.com/global-climate/ here].</ref>

A reanalysis of weather station data for 1943 to 2012 by Roy Spencer shows that after a cooler period in the 1960s and 1970s, U.S. temperatures returned to their earlier level. Unlike CRU, NASA, and NOAA, Spencer corrects for the fact that at most stations measurement time of day has changed over the years.<ref name=Spencer>Spencer, Roy, "[http://www.drroyspencer.com/2012/08/a-new-analysis-of-u-s-temperature-trends-since-1943/ A New Analysis of U.S. Temperature Trends Since 1943]," August 6th, 2012.</ref> So Spencer's analysis implies that the warmest year on record was 1934, the warmest year of the 1930s, not 2016 as the climate establishment maintains. Spencer is a prominent skeptic and a professor at the University of Alabama in Huntsville. He maintains the UAH record, one of the two major satellite temperature records. As an active researcher at the center of the climate science community, Spencer is a standing rebuke to the claim that AGW represents the scientific consensus.<ref>Spencer, Roy, "[http://www.drroyspencer.com/my-global-warming-skepticism-for-dummies/ My Global Warming Skepticism, for Dummies]"</ref>

A reanalysis of weather station data for 1943 to 2012 by Roy Spencer shows that after a cooler period in the 1960s and 1970s, U.S. temperatures returned to their earlier level. Unlike CRU, NASA, and NOAA, Spencer corrects for the fact that at most stations measurement time of day has changed over the years.<ref name=Spencer>Spencer, Roy, "[http://www.drroyspencer.com/2012/08/a-new-analysis-of-u-s-temperature-trends-since-1943/ A New Analysis of U.S. Temperature Trends Since 1943]," August 6th, 2012.</ref> So Spencer's analysis implies that the warmest year on record was 1934, the warmest year of the 1930s, not 2016 as the climate establishment maintains. Spencer is a prominent skeptic and a professor at the University of Alabama in Huntsville. He maintains the UAH record, one of the two major satellite temperature records. As an active researcher at the center of the climate science community, Spencer is a standing rebuke to the claim that AGW represents the scientific consensus.<ref>Spencer, Roy, "[http://www.drroyspencer.com/my-global-warming-skepticism-for-dummies/ My Global Warming Skepticism, for Dummies]"</ref>

The temperature records preferred by the climate establishment were built up over many years and include numerous gaps, bugs, incompatible coding, and other errors. The problems of the CRU data set are memorably documented in the "Harry read me" file, part of the Climategate trove. According to this file, the premier global temperature record contains, "botch after botch after botch."<ref name=Brownlow>Brownlow, Andie, "[https://pjmedia.com/blog/climategates-harry_read_me-txt-we-all-really-should/?singlepage=true Climategate's Harry_Read_Me.txt: We All Really Should]", Dec. 11, 2009.</ref>

The temperature records preferred by the climate establishment were built up over many years and include numerous gaps, bugs, incompatible coding, and other errors. The problems of the CRU data set are memorably documented in the "Harry read me" file, part of the Climategate trove. According to this file, the premier global temperature record contains, "botch after botch after botch."<ref name=Brownlow>Brownlow, Andie, "[https://pjmedia.com/blog/climategates-harry_read_me-txt-we-all-really-should/?singlepage=true Climategate's Harry_Read_Me.txt: We All Really Should]", Dec. 11, 2009.</ref>

AGW is hardly the only explanation that has been proposed for recent warming. There are also explanations involving natural cycles such as the 11-year-sunspot cycle, the Pacific decadal oscillation,<ref>Bratcher and Giese, "Tropical Pacific decadal variability and global warming", ''Geophysical Research Letters''.</ref> and the El Niño-Southern Oscillation (ENSO).<ref>*72 percent of global temperature variation since 1958 reflects the influence of a Pacific Ocean weather cycle called the El Niño-Southern Oscillation (McLean, J. D., C. R. de Freitas, and R. M. Carter (2009-07-23). "Influence of the Southern Oscillation on tropospheric temperature". ''Journal of Geophysical Research''<br/>*Spencer, R.W. & Braswell, W.D., "[http://link.springer.com/article/10.1007/s13143-014-0011-z The role of ENSO in global ocean temperature changes during 1955–2011 simulated with a 1D climate model]", Asia-Pacific J Atmos Sci (2014) 50: 229. doi:10.1007/s13143-014-0011-z</ref>

AGW is hardly the only explanation that has been proposed for recent warming. There are also explanations involving natural cycles such as the 11-year-sunspot cycle, the Pacific decadal oscillation,<ref>Bratcher and Giese, "Tropical Pacific decadal variability and global warming", ''Geophysical Research Letters''.</ref> and the El Niño-Southern Oscillation (ENSO).<ref>*72 percent of global temperature variation since 1958 reflects the influence of a Pacific Ocean weather cycle called the El Niño-Southern Oscillation (McLean, J. D., C. R. de Freitas, and R. M. Carter--2009-07-23). "Influence of the Southern Oscillation on tropospheric temperature". ''Journal of Geophysical Research''<br/>*Spencer, R.W. & Braswell, W.D., "[http://link.springer.com/article/10.1007/s13143-014-0011-z The role of ENSO in global ocean temperature changes during 1955–2011 simulated with a 1D climate model]", Asia-Pacific J Atmos Sci (2014) 50: 229. doi:10.1007/s13143-014-0011-z</ref>

==Summary of arguments against anthropogenic global warming==

==Summary of arguments against anthropogenic global warming==

Natural periods of global warming and global cooling are expected to occur regardless of human activity, and not long ago liberals were demanding more government control to combat an alleged cooling in temperatures, with some scientists warning of a possible ice age.<ref <ref name="Time">"Science: Another Ice Age?" (June 24, 1974).  ''Time'' magazine.  Retrieved on September 25, 2014.</ref>  [[Global cooling]], a theory that predates global warming, obviously occurs naturally many times throughout [[Earth|Earth's]] geological history.<ref name="dissidents">"After any given warming phase begins, thousands of years later the cyclical [[Milankovitch]] decrease in the sun's heat kicks in. The warming stops, reverses and an [[ice age]] ensues."  Cockburn, Alexander (June 9–11, 2007).  [http://www.counterpunch.org/cockburn06092007.html "Dissidents against dogma"].  Counterpunch.  Retrieved on September 25, 2014.</ref> The ease of refutation of anthropogenic global cooling claims foretells the eventual fate of the current global warming hysteria.

Natural periods of global warming and global cooling are expected to occur regardless of human activity, and not long ago liberals were demanding more government control to combat an alleged cooling in temperatures, with some scientists warning of a possible ice age.<ref name="Time">"Science: Another Ice Age?" (June 24, 1974).  ''Time'' magazine.  Retrieved on September 25, 2014.</ref>  [[Global cooling]], a theory that predates global warming, obviously occurs naturally many times throughout [[Earth|Earth's]] geological history.<ref name="dissidents">"After any given warming phase begins, thousands of years later the cyclical [[Milankovitch]] decrease in the sun's heat kicks in. The warming stops, reverses and an [[ice age]] ensues."  Cockburn, Alexander (June 9–11, 2007).  [http://www.counterpunch.org/cockburn06092007.html "Dissidents against dogma"].  Counterpunch.  Retrieved on September 25, 2014.</ref> The ease of refutation of anthropogenic global cooling claims foretells the eventual fate of the current global warming hysteria.

Many political activists use the term "global warming" to refer to [[anthropogenic global warming theory]] (AGW), which asserts that human activity such as spewing "[[greenhouse gases]]" is causing an increase in temperature and is more significant than natural causes. The AGW theory is supported by left-leaning political parties, as well as a majority of sovereign states, national agencies, and an intergovernmental panel (see [[IPCC]]). The reality is that there is no immediate global crisis, and even dire warnings by the UN's [[Intergovernmental Panel on Climate Change]] (IPCC) admit that significant effects will not be manifested for at least 100 years. Predictions made by [[climate model]]s publicized by the IPCC have not come to pass in recent years. Many scientists, such as Hal Lewis, have decried global warming as a conspiracy for the purpose of securing trillions of dollars in grant money.

Many political activists use the term "global warming" to refer to [[anthropogenic global warming theory]] (AGW), which asserts that human activity such as spewing "[[greenhouse gases]]" is causing an increase in temperature and is more significant than natural causes. The AGW theory is supported by left-leaning political parties, as well as a majority of sovereign states, national agencies, and an intergovernmental panel (see [[IPCC]]). The reality is that there is no immediate global crisis, and even dire warnings by the UN's [[Intergovernmental Panel on Climate Change]] (IPCC) admit that significant effects will not be manifested for at least 100 years. Predictions made by [[climate model]]s publicized by the IPCC have not come to pass in recent years. Many scientists, such as Hal Lewis, have decried global warming as a conspiracy for the purpose of securing trillions of dollars in grant money.