Industrial Revolution started in mid 18th century in Europe. For close to 100 years human civilisation used coal to power its ships, trains, power plants to produce electricity, stoves at home to cook food and to keep themselves warm from biting cold during winters.
Since the dawn of 20th century another fuel option was added to it that had equal ability to pollute our environment. It was petroleum. Over night all the ships started running on new fuel. A new medium of transport – airplane used it in ever-increasing quantity.
After the Second World War ended in 1945 and many nations in Asia and Africa came out of colonial rule their aspiration for good living led to rapid increase in the use of public transport, mechanization of agriculture, air travel and industrialsation. Smoke and smog filled cities and dock areas, stench of diesel and petrol fumes in the air, skin and other health disorders, respiratory problems all of them were considered par for the course if you were on the path of development.
The first theory of global warming came in 1824 when French mathematician Jean Baptiste Joseph Fourier discovered that the Earth's temperature was slowly increasing. Fourier argued that the earth's atmosphere traps solar radiation and reflects it back toward the earth.
In the late 19th century Fourier's theory was labeled the “greenhouse effect" when Swedish scientist Svante Arrhenius coined the term to explain how CO2 traps heat in the Earth's atmosphere. He was the first one to come with a hypothesis that carbondioxide and water vapour absorbed sun’s heat and maintained earth’s average surface temperature at 15 degree celcius. Till the second half of the 20th century scientists didn’t take this theory seriously.
However, in the 1950s, amateur scientist G.S. Callendar warned that the greenhouse effect was true and dramatically impacting the atmosphere of the Earth. Callendar's claims were termed the "Callendar effect," and led to increased research on global warming. Within two decades scientist developed many models to measure how climate was behaving and how various gases were impacting it. Also they tried to figure out how much of it was man made.
While the research was on scientific community was divided over their own finding. Some were of the opinion that the globe was cooling while the others argued that the CO2 and other greenhouse gases were on the rise and so eventually it would lead to an increase in the temperature worldwide.
Finally in the 1980's the global annual mean temperature curve started to rise. By late 1980's the rising trend was so steep that the global warming theory gained currency among the educated elite of the world. Scientist Stephen Schneider had first predicted global warming in 1976.
According to International Protocol on Climate Change (IPCC), United Nation’s body that looks into climate related issues, global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) between the start and the end of the 20th century. The IPCC’s latest findings suggest that most of the observed temperature increase since the middle of the 20th century was caused by increasing concentrations of greenhouse resulting from human activity such as fossil fuel (Coal and petroleum) burning and cutting down of forests.
Using climate models’ projections in the latest IPCC report it looks that the global surface temperature will probably rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the twenty-first century. The uncertainty in this estimate arises from the use of models with differing sensitivity to greenhouse gas concentrations and the use of differing estimates of future greenhouse gas emissions.