The science of climate change has been the subject of study for almost two centuries. Global warming was first addressed by French mathematician Joseph Fourier who described the greenhouse effect in 1824. The relationship between atmospheric CO2 and temperature increases was explored by Swedish scientist Svante August Arrhenius in 1903 and climate feedback effects were documented by Russian climatologist Mikhail Budyko in the 1950s. In 1954 the California Institute of Technology outlined the link between fossil fuels and increased levels of atmospheric CO2. Subsequently a researcher at Humble Oil Co. found that the carbon isotopes in tree rings corroborate the unpublished Caltech findings.
In 1959 Nuclear physicist Edward Teller addressed warned that carbon emissions from fossil fuels would warm the Earth and cause sea levels to rise. Here is an excerpt of his talk titled "Energy Patterns of the Future":
"Carbon dioxide has a strange property. It transmits visible light but it absorbs the infrared radiation which is emitted from the earth. Its presence in the atmosphere causes a greenhouse effect," Teller said. "It has been calculated that a temperature rise corresponding to a 10 per cent increase in carbon dioxide will be sufficient to melt the icecap and submerge New York. All the coastal cities would be covered, and since a considerable percentage of the human race lives in coastal regions, I think that this chemical contamination is more serious than most people tend to believe."
In 1960, Charles Keeling first published the measurements of atmospheric carbon that have come to be known as the "Keeling curve". In the late 1950s observations at the Mauna Loa Observatory in Hawaii measured 315 parts per million (ppm) of atmospheric carbon today we see levels in excess of 410 (ppm). The Earth has not been at these levels in more than a million years.
In 1964 President Johnson’s Science Advisory Committee submitted a report titled "Restoring the Quality of Our Environment," which linked carbon emissions from the burning of fossil fuels to global warming. This report warned that time was running out and it further laid out the solution:
"… the pollution from internal combustion engines is so serious, and is growing so fast, that an alternative nonpolluting means of powering automobiles, buses, and trucks is likely to become a national necessity."A 1968 Stanford Research Institute report warned that increasing levels of CO2 cause climate change:
"Significant temperature changes are almost certain to occur by the year 2000, and these could bring about climatic changes...there seems to be no doubt that the potential damage to our environment could be severe...pollutants which we generally ignore because they have little local effect, CO2 and submicron particles, may be the cause of serious world-wide environmental changes."In 1975 Wallace Smith Broecker popularized the term 'global warming' in a remarkably accurate paper that correctly predicted increasing atmospheric CO2 would warm the planet. Broecker was also the first to recognize the global system of ocean currents now called the Ocean Conveyor Belt. This is a tipping point which he referred to as the "Achilles heel of the climate system". He predicted that minor temperature increases could keep the water from sinking in the North Atlantic and this could shut down the conveyor and impact global weather patterns.
In 1988, NASA scientist James Hansen told a U.S. congressional committee that there is a cause and effect relationship between greenhouse gasses and observed warming. Increasing atmospheric emissions are part of "an experiment that could have devastating effects," Broecker said in 1997. "We're playing with an angry beast — a climate system that has been shown to be very sensitive."
Taken as a whole the science supporting the existence of anthropogenic climate change is unassailable. As explained by the Royal Society:
"Rigorous analysis of all data and lines of evidence shows that most of the observed global warming over the past 50 years or so cannot be explained by natural causes and instead requires a significant role for the influence of human activities."Climate change is now the most studied phenomenon in human history and the body of evidence is irrefutable. There is no reason to doubt the thousands of studies that corroborate the finding that anthropogenic factors are heating the planet to dangerous levels.