When did global warming first occur?

Answer 1

Global warming is both a natural process and a human induced process

natural global warming started which the formation of the oceans resulting in water vapour trapping heat.

Human induced global warming occurs mostly after the industrial revolution when fossil fuels became heavily used and burnt releasing stored co2.

Answer 2

When the Northwest Passage between the North Atlantic and the North Pacific, above Canada, became mostly ice-free during the summer months, that's when most people agreed that global warming was a fact.

Svante Arrhenius thought the burning of coal might alter our environment a little bit. That was in the late 19th century. He conclusively demonstrated that CO2 was a heat trapping gas.

It wasn't until the 1950s, when we set up really good monitoring stations, that we could measure seasonal fluctuations in CO2 and the yearly increase from human activity. Scientists became increasingly concerned about the environmental impact of human activity during the 1960s, but temperature declines in the early 1970s alleviated those concerns. With record breaking temperatures, glacial retreat, and other signs of significant change occurring in the 1980s, most climate researchers became convinced humans were the primary cause.

As the data continued to be gathered and analyzed, the major consensus that had developed among scientists in the 1980s congealed into an overwhelming agreement by the 21st century.

Answer 3

Many tens of thousands of years ago.

Global warming, or more accurately, climate change happens in cycles. The earth has undergone several ice ages for instance and there is some evidence to suggest that another is due.

Perhaps the changes in climate patterns we are seeing presently are a harbinger of that.

Certainly the impact of man-kinds technology has affected the entire environment, not always for the good.

Fate has been kind enough to provide Venus as an example what a runaway greenhouse effect can do to an entire planet without the aid of man.

It behoves us to take note and not exacerbate the present situation on earth. Our only home.

Answer 4

The recent sudden rise in temperature began at the start of the Industrial Revolution when we began burning fossil fuels (coal, oil and natural gas) about 250 years ago.

This is a very short time for such a change in temperature, which normally takes thousands of years.

Answer 5

Even though the earths climate has allways been changing from hot to cold and back again, we consider the pollution to be the start of global warming.

Pollution startet to become very heavy with the Industrial Revolution.

Late 17th century/Early 18th century.

Answer 6

Around the mid 1900's it started to get noticeable.

Answer 7

it still does