The film begins by highlighting what its makers assert are a number of contradictions and inconsistencies in the evidence supporting the theory of man-made global warming.
Atmospheric carbon dioxide levels and temperature change since 1940. The film asserts that records of atmospheric CO2 levels since 1940 show a continuing increase, but during this period, global temperature decreased until 1975, and has increased since then.
Variations in warming rate. The programme states that all models of greenhouse effect-derived temperature increase predict that the warming will be at its greatest for a given location in the troposphere and at its lowest near the surface of the earth. The programme asserts that current satellite and weather balloon data do not support this model, and instead show that the surface warming rate is greater than or equal to the rate in the lower troposphere.
Increases in CO2 and temperatures following the end of ice ages. According to the film, increases in CO2 levels lagged behind temperature increases during glacial terminations.
EPICA and Vostok ice cores display the relationship between temperature and level of CO2 for the last 650,000 years.
Relationship between atmospheric carbon dioxide levels and temperature change. The film asserts that carbon dioxide levels increase or decrease as a result of temperatures increasing or decreasing rather than temperatures following carbon dioxide levels, because as the global climate cools the Earth's oceans absorb carbon dioxide, and as the climate warms the oceans release carbon dioxide.
Influence of oceanic mass on temperature changes. The programme argues that due to the very large mass of the world's oceans, it takes hundreds of years for global temperature changes to register in oceanic mass, which is why analysis of the Vostok Station and other ice cores shows that changes in the level of atmospheric carbon dioxide follow changes in global temperature by 800 years.
Influence of water vapour on climate change. According to the film, water vapour makes up 95% of all greenhouse gases and has the largest impact on the planet's temperature. Water particles in the form of clouds act to reflect incoming solar heat, but the film argues that the effects of clouds cannot be accurately simulated by scientists attempting to predict future weather patterns and their effects on global warming.
Influence of carbon dioxide on climate change. The film states that carbon dioxide comprises only a very minuscule amount - just 0.054% of the Earth's atmosphere. According to the film, human activity contributes much less than 1% of that, while volcanoes produce significantly more CO2 per year than humans, while plants and animals produce 150 gigatons of CO2 each year. Dying leaves produce even more CO2, and the oceans are "the biggest source of CO2 by far." Human activity produces a mere 6.5 gigatons of CO2 each year. The film concludes that man-made CO2 emissions alone cannot be causing global warming. (Durkin subsequently acknowledged that the claim about volcanic CO2 emissions was wrong, and removed the claim from later versions.[19]))
Influence of the sun on climate change. The film highlights the solar variation theory of global warming, asserting that solar activity is currently at an extremely high level, and that this is directly linked to changes in global temperature. The posited mechanism involves cosmic rays as well as heat from the sun aiding cloud formation.[20] The film argues that the activity of the sun is far more influential on global warming and cooling than any other man-made or natural activity on Earth.
Previous episodes of warming. The programme asserts that the current episode of global warming is nothing unusual and temperatures were even more extreme during the Medieval Warm Period, a time of great prosperity in western Europe.
