global warming will set in with a vengeance after 2009,

spurred by the greenhouse effect

researchers at Britain's Met Office, which deals with meteorology, have made a computer model that takes into account such natural phenomena as the El Nino pattern in the Pacific Ocean

climate could be dominated over this period by these natural changes, rather than human-caused global warming.

natural forces will offset the expected warming caused by human activities, such as the burning of fossil fuels, which releases the greenhouse gas carbon dioxide.

Over the 100-year timescale, the main change is going to come from greenhouse gases t

Industrial pollution brought a seven-fold increase in soot - also known as black carbon - in Arctic snow during the late 19th and early 20th centuries

letting Earth's surface absorb more solar energy and possibly resulting in earlier snow melts and exposure of much darker underlying soil, rock and sea ice.

This in turn led to warming across much of the Arctic region.