My read of OP's point was that the fundamental science has long been known. The problem was recognised at a global scale both publicly and at high levels of government by the 1960s. Denialism is strong in the United States, but as with other recent (and ongoing) global crises, also prevalent elsewhere.

For a timeline of awareness of the problem we can go back over 200 years for early insights:

1800-1870: Level of carbon dioxide gas (CO₂) in the atmosphere, as later measured in ancient ice, is about 290 ppm (parts per million).

Mean global temperature (1850-1870) is about 13.6°C.

First Industrial Revolution. Coal, railroads, and land clearing speed up greenhouse gas emission, while better agriculture and sanitation speed up population growth.

1824: Fourier calculates that the Earth would be far colder if it lacked an atmosphere.

1859: Tyndall discovers that some gases block infrared radiation. He suggests that changes in the concentration of the gases could bring climate change.

1896: Arrhenius publishes first calculation of global warming from human emissions of CO₂.

1897: Chamberlin produces a model for global carbon exchange including feedbacks.

1870-1910: Second Industrial Revolution. Fertilizers and other chemicals, electricity, and public health further accelerate growth.

1914-1918: World War I; governments learn to mobilize and control industrial societies.

1920-1925: Opening of Texas and Persian Gulf oil fields inaugurates era of cheap energy.

1930s Global warming trend since late 19th century reported.

Milankovitch proposes orbital changes as the cause of ice ages.

1938: Callendar argues that CO₂ greenhouse global warming is underway, reviving interest in the question.

1939-1945: World War II. Military grand strategy is largely driven by a struggle to control oil fields.

1945: US Office of Naval Research begins generous funding of many fields of science, some of which happen to be useful for understanding climate change.

1956: Ewing and Donn offer a feedback model for quick ice age onset.

Phillips produces a somewhat realistic computer model of the global atmosphere.

Plass calculates that adding CO₂ to the atmosphere will have a significant effect on the radiation balance.

1957: Launch of Soviet Sputnik satellite. Cold War concerns support 1957-58 International Geophysical Year, bringing new funding and coordination to climate studies.

Revelle finds that CO₂ produced by humans will not be readily absorbed by the oceans.

1958: Telescope studies show a greenhouse effect raises temperature of the atmosphere of Venus far above the boiling point of water.

1960: Mitchell reports downturn of global temperatures since the early 1940s.

Keeling accurately measures CO₂ in the Earth's atmosphere and detects an annual rise.

1962: Cuban Missile Crisis, peak of the Cold War.

1963: Calculations suggest that feedback with water vapor could make the climate acutely sensitive to changes in CO₂ level.

1965: Boulder, Colo. meeting on causes of climate change: Lorenz and others point out the chaotic nature of climate system and the possibility of sudden shifts.

1966: Emiliani's analysis of deep-sea cores and Broecker's analysis of ancient corals show that the timing of ice ages was set by small orbital shifts, suggesting that the climate system is sensitive to small changes.

1967: International Global Atmospheric Research Program established, mainly to gather data for better short-range weather prediction, but including climate.

Manabe and Wetherald make a convincing calculation that doubling CO₂ would raise world temperatures a couple of degrees.

1968: Studies suggest a possibility of collapse of Antarctic ice sheets, which would raise sea levels catastrophically.

1969: Astronauts walk on the Moon, and people perceive the Earth as a fragile whole.

Budyko and Sellers present models of catastrophic ice-albedo feedbacks.

Nimbus III satellite begins to provide comprehensive global atmospheric temperature measurements.

1970: First Earth Day. Environmental movement attains strong influence, spreads concern about global degradation.

Creation of US National Oceanic and Atmospheric Administration, the world's leading funder of climate research.

Aerosols from human activity are shown to be increasing swiftly. Bryson claims they counteract global warming and may bring serious cooling.

1971: SMIC conference of leading scientists reports a danger of rapid and serious global change caused by humans, calls for an organized research effort.

Mariner 9 spacecraft finds a great dust storm warming the atmosphere of Mars, plus indications of a radically different climate in the past.

1972: Ice cores and other evidence show big climate shifts in the past between relatively stable modes in the space of a thousand years or so, especially around 11,000 years ago.

Droughts in Africa, Ukraine, India cause world food crisis, spreading fears about climate change.

1973: Oil embargo and price rise bring first "energy crisis".

1974: Serious droughts since 1972 increase concern about climate, with cooling from aerosols suspected to be as likely as warming; scientists are doubtful as journalists talk of a new ice age.

1975: Warnings about environmental effects of airplanes leads to investigations of trace gases in the stratosphere and discovery of danger to ozone layer.

Manabe and collaborators produce complex but plausible computer models which show a temperature rise of several degrees for doubled CO₂.

1976: Studies show that CFCs (1975) and also methane and ozone (1976) can make a serious contribution to the greenhouse effect.

Deep-sea cores show a dominating influence from 100,000-year Milankovitch orbital changes, emphasizing the role of feedbacks.

Deforestation and other ecosystem changes are recognized as major factors in the future of the climate.

Eddy shows that there were prolonged periods without sunspots in past centuries, corresponding to cold periods .

1977: Scientific opinion tends to converge on global warming, not cooling, as the chief climate risk in next century.

1978: Attempts to coordinate climate research in US end with an inadequate National Climate Program Act, accompanied by rapid but temporary growth in funding.

1979: Second oil "energy crisis." Strengthened environmental movement encourages renewable energy sources, inhibits nuclear energy growth.

US National Academy of Sciences report finds it highly credible that doubling CO₂ will bring 1.5-4.5°C global warming.

World Climate Research Programme launched to coordinate international research.

1981: Election of Reagan brings backlash against environmental movement to power. Political conservatism is linked to skepticism about global warming.

http://www.aip.org/history/climate/timeline.htm