Global warming began in 1940s

Sydney: Although climate change has become a major concern in recent years, new research has found that clear signs of global warming emerged as early as 1940s in parts of South East Asia, Australia, and Africa.

The reason the first changes in average temperature and temperature extremes appeared in the tropics was because those regions generally experienced a much narrower range of temperatures, the study said.

This meant smaller shifts in the temperature record due to global warming were more easily seen.Closer to the poles the emergence of climate change in the temperature record appeared later but by the period 1980-2000 the temperature record in most regions of the world were showing clear global warming signals.

One of the few exceptions to this clear global warming signal was found in large parts of the continental US, particularly on the Eastern coast and up through the central states.