Activities by human beings is causing global warming for almost two centuries, says new research, suggesting that human-induced climate change is not just a 20th century phenomenon.
It said warming began during early stages of the industrial revolution and was first noticed in the Arctic and tropical oceans around the 1830s, which later spread to Europe, Asia and North America.
Nonetheless, climate warming seems to have been delayed in the Antarctic, perhaps due to the way ocean circulation is pushing warming waters to the North and away from the frozen continent, the researchers said.
"The climate warming we are witnessing today started about 180 years ago," said lead researcher Nerilie Abram , Associate Professor at The Australian National University (ANU) in Canberra.
"In the tropical oceans and the Arctic in particular, 180 years of warming has already caused the average climate to emerge above the range of variability that was normal in the centuries prior to the Industrial Revolution," he added.
Human beings only caused small increases in the level of greenhouse gases in the atmosphere during the 1800s.
"But, the early onset of warming detected in this study indicates the Earth's climate did respond in a rapid and measureable way to even the small increase in carbon emissions during the start of the industrial age," explained Helen McGregor from the University of Wollongong in New South Wales, Australia.