Burning coal releases carbon dioxide which traps heat from the Sun, raising temperatures. But it also emits particles of sulphur that help block the Sun’s rays and cool the Earth.

But it is thought temperatures will rise again now China is tackling air pollution by installing equipment to scrub out sulphur particles.‘During the Chinese economic expansion there was a huge increase in sulphur emissions,’ Dr Robert Kaufmann, of Boston University, told the journal Proceedings of the National Academy of Sciences.

Some have suggested that injecting sulfur compounds into the atmosphere might help ease global warming by increasing clouds and haze that would reflect sunlight, but an earlier study concluded that would be a bad idea.

Injecting enough sulfur to reduce warming would wipe out the Arctic ozone layer and delay recovery of the Antarctic ozone hole by as much as 70 years, according to an analysis by Simone Tilmes of the National Center for Atmospheric Research in Boulder, Colorado.

'While climate change is a major threat, more research is required before society attempts global geoengineering solutions,' said Tilmes.

Overall, global temperatures have been increasing for more than a century since the industrial revolution began adding gases like carbon dioxide to the air.

But there have been similar plateaus, such as during the post-World War II era when industrial production boosted sulfur emissions in several parts of the world, Kaufmann explained.

Atmospheric scientists and environmentalists are concerned that continued rising temperatures could have serious impacts worldwide, ranging from drought in some areas, changes in storm patterns, spread of tropical diseases and rising sea levels.