The mainstream "consensus" on anthropogenic global warming (AGW) says the atmospheric concentration of carbon dioxide (CO2) remained stable for millions of years, until the Industrial Revolution, when it went from 280 ppm in 1750 to 414.7 ppm in 2019.  Environmentalists blame this on man's consumption of fossil fuels, which has increased significantly since the early 1900s.

In support of the "consensus" view, climate change researchers write: "[T]he current CO2 concentration is unprecedented over the past 3 million years[.] ... [G]lobal temperature never exceeded the preindustrial value by more than 2°C during the Quaternary" (Willeit et al., 2019).  Environmentalists predict that, as anthropogenic CO2 rises, there will be more and more natural disasters, threatening the lives of millions of people around the world.  These include more frequent and severe hurricanes, widespread flooding, extreme heat waves, and prolonged drought. 

Belief in the dangers of AGW has led to the emergence of "climate change science," an interdisciplinary field that is very different from the natural sciences.  Regular scientists rely on objective, empirical methods to test hypotheses.  Climate change scientists, on the other hand, manipulate data to fit preconceived beliefs; they are trained to ignore hypotheses challenging the AGW status quo, no matter how plausible.  In the natural sciences, governments fund different avenues of research; in climate change science, only AGW receives funding because it is "politically correct."  Climate change scientists are expected to uncover positive correlations between anthropogenic CO2 and temperature; if they cannot find one, it will have to be manufactured out of thin air.  Not only is there no research money for those seeking alternative explanations of climate change, but any attempt at falsifying the AGW hypothesis is considered heresy.  Those who question the IPCC (Intergovernmental Panel on Climate Change)'s findings are dismissed as cranks challenging a well established scientific "consensus."  Climate change science has more in common with Lysenkoism than actual science.

Climate change scientists are not above using ad hominem rhetoric to silence legitimate debate.  Geologists and other researchers who disagree with AGW are dismissed as "climate deniers," even though no scientifically literate person denies that climate always changes.

In 2008, NASA's James Hansen, whose testimony before the U.S. Congress in 1988 began the AGW scare, demanded that fossil fuel company CEOs be tried for "high crimes against humanity and nature."  Prosecution for thoughtcrime is apparently warranted because of refusal to accept mainstream "consensus" on AGW.  In 2014, the pro-AGW documentary Merchants of Doubt smeared noted American physicist Fred Singer as a "liar."  Singer threatened to sue the film director for libel.

In 2009, a server at the University of East Anglia's Climate Research Unit (CRU) was hacked, and thousands of emails were leaked.  These emails revealed a world seldom seen by the public, where manipulation of data and willful suppression of evidence had replaced scientific objectivity.  Free from the glare of public scrutiny, the CRU disregarded the scientific method in pursuit of a political agenda.

The emails tell a tale of corruption at the highest levels of academia.  In one email, a climate change scientist who had uncovered a decreasing trend in Northern Hemispheric temperatures was told to "hide the decline" using "Mike's Nature trick."  By padding the trend with "instrumental" or thermometer data, the proxy temperature record was adjusted to reflect mainstream "consensus."  In other emails, Freedom of Information Act (FOIA) requests were routinely evaded and incriminating emails hurriedly deleted.  Scientists who disagreed with the CRU were ridiculed and bullied.  The scandal, known as "Climategate," revealed a conspiracy among scientists to feed biased information to the IPCC.  In the aftermath, the CRU's top scientists narrowly escaped criminal prosecution because of a legal technicality.

In addition to its proponents' questionable conduct, there are numerous problems with the evidence of AGW.  Environmental activists typically rely on scientific "consensus" and the "hockey stick" graph to prove it.  Claims of overwhelming scientific "consensus" on AGW are sourced from Cook, et al. (2013), a team of volunteers affiliated with SkepticalScience.com, a pro-AGW website.  The study supposedly found that 97% of the scientific community endorses AGW.  Re-analysis of the data revealed significant bias and unrepresentative sample sizes.  Cook, et al. had excluded 75% of all papers discussing climate change.  Geologists have long known about climatic fluctuations across geological and evolutionary timescales, but studies from geology and other earth sciences were woefully undersampled.  Cook and his team of volunteers were taken to task for mistaking "a trend in composition for a trend in endorsement" (Tol, 2014).

Michael Mann's iconic "hockey stick" (1998), the centerpiece of the IPCC's case for AGW, ignited a firestorm of controversy and debate in the early 2000s, thanks to the efforts of Canadian researchers McIntyre and McKitrick.  The original graph showed Northern Hemispheric mean temperature increasing dramatically after the early 1900s; this rising trend, when depicted graphically, resembled a "hockey stick."  McIntyre and McKitrick (2003) re-analyzed Mann's data, concluding that it was "primarily an artefact of poor data handling, obsolete data and incorrect calculation of principal components."  They also uncovered a late–15th century "Medieval Warming Period," when temperatures were higher than they are now.

Mann was criticized for using a computer algorithm that "mined for hockey stick shapes and overstated their dominance in the underlying data patterns" (McKitrick, 2014).  His proxy temperature data for the "hockey stick" were based on tree ring analysis, which does not produce accurate results because ring width is influenced by soil conditions, amount of sunlight and rainfall, humidity, and CO2 availability.  These effects must be disentangled before the data can be properly interpreted.

The IPCC believes that rising anthropogenic CO2 reduces ocean buffer capacity; if the ocean can't absorb excess CO2, it remains trapped in the atmosphere with nowhere to go.  As climate physicist Edwin X. Berry pointed out (2019), if this were true, concentration of atmospheric CO2 would be many times higher than it is now, given average CO2 variation across geological and evolutionary timescales.  The IPCC apparently believes that anthropogenic and non-anthropogenic CO2 have the same molecular formulas but different molecular structures, a preposterous assumption that violates the laws of chemistry and physics.

The most accurate models always supply us with an explanation that best fits the data.  Berry's simple mathematical model "shows how CO2 flows through the atmosphere and produces a balance level where outflow equals inflow."  After nuclear testing during the 1950s and '60s, there was a temporary accumulation of C₁₄ in the atmosphere, which eventually dissipated after 1970.  In order for the Bern model to be correct, this man-made CO₁₄ would have remained trapped in the atmosphere.  The data show this to be false, forcing us to conclude that Berry's "physics model" is the most accurate explanation.

AGW is clearly not supported by the data, so what causes rising average global temperatures?

There is evidence that climate change is affected by solar magnetic flux, although the precise mechanism is still under debate.  The most common theory suggests an inverse correlation between sunspot activity and cosmic ray intensity.  During low sunspot activity, expansion of the sun's corona produces faster and stronger solar winds.  These shield the heliosphere from interstellar cosmic rays, which are needed for ionization of aerosols in Earth's atmosphere.  If ionization fails to produce enough charged particles, there is less formation of cloud condensation nuclei (CNNs), the "surface" area for water vapor condensation.  Without sufficient cloud cover, incoming solar radiation will raise average global temperature because it is not being reflected back into outer space (Svensmark, 2019).

Environmentalists like to believe that there is a climate "control knob," but we have as much control over the climate as King Canute of England had over the tides.  AGW is a malicious fraud based on spurious correlation and post hoc, ergo propter hoc reasoning.  The question remains to be asked: if AGW is so obviously wrong, why does the IPCC continue to promote it as if it were actually true?  The answer is money and power.  This means more money and power for governments, which get to collect carbon taxes and impose cap and trade policies, and for the IPCC and other U.N. bodies, which get to dictate global environmental policy and transfer billions of dollars from the West to third-world countries.