Climate Change Timeline
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We have long known of the heat retaining properties of carbon dioxide in the atmosphere.
This was proposed in the early 1800s by the French scientist Joseph Fourier (Van der Veen 2000), that the earth’s atmosphere retained some of the heat entering as sunlight, as happens in a glass greenhouse, that is, longwave radiation passes through the glass to the soil and surfaces within, which are heated, the heat is then emitted as shortwave radiation, infrared, which can’t pass through the glass as well.
The French historian Edmé Mariotte (Cirella & Tao 2009) in 1681 observed the sun’s light passed through glass but heat from hot surfaces didn’t. Irish scientist John Tyndall (Somerville 2011) later conducted laboratory experiments on coal gas which demonstrated that carbon dioxide, methane and hydrocarbons absorbed heat at different wave lengths of sunlight.
Late in that century Swedish chemist Svante Arrhenius (Charlson et al. 1997) calculated that decreasing and increasing atmospheric carbon dioxide content had marked effects on global temperature.
Even though these early scientists and others were making observations and hypotheses, it wasn’t until the 1930s that British engineer Guy Stewart Callendar (Anderson et al. 2006) turned his research to the anthropogenic, produced by human activities, nature of an increasing global temperature and the industrial revolution.
Although Callendar’s research was not widely accepted it did result in funding provisions for recording atmospheric carbon dioxide, CO2, levels.
Dr Charles David Keeling (Keeling et al. 1976) was the scientist who started measuring atmospheric carbon dioxide concentrations in the late 1950s and argued for that available funding, and as such, carbon dioxide concentrations have been continuously measured to this current day.
He established the monitoring station in Hawaii at Mauna Loa on a volcanic mountain located on sheet rock and as a result it is far from local manmade and natural CO2 sources and variation due to photosynthesis.
Keeling established a baseline by 1958 and two years later he reported that CO2 levels were rising and over time, this became the now well known ‘Keeling curve’ in the graph clearly showing the increase in CO2 concentration.
