Global warming has been on “pause” for 15 years but will speed up again and is still a real threat, Met Office scientists have warned.
Surface temperatures around the world have not increased on average since the late 1990s, causing some sceptics to suggest that climate change is not happening as quickly as experts predict.
But in a set of three new reports, the Met Office claims that global warming has been disguised in recent years by the oceans, which have absorbed greater amounts of heat and prevented us from noticing the difference at surface level.
This process, caused by the natural cycle of the oceans, could delay earlier predictions of global warming by five to ten years but will not last forever, researchers explained.
Other factors including a number of volcanic eruptions since 2000 and changes in the Sun’s activity, could also have masked the effect of greenhouse gases by providing a slight cooling effect, they said.
The Met Office has predicted it could be another five years before surface temperatures begin to rise again, but said the current “pause” would not affect long-term global warming forecasts.
Dr Peter Stott, head of climate monitoring at the Met Office, said: “Global surface temperatures remain high. Twelve of the 14 warmest years on record have occurred since 2000, the lower troposphere – the atmosphere above the surface – is continuing to warm in recent years, and combined with the cooling in the stratosphere this is a distinctive fingerprint of the effects of greenhouse gases on the climate system.”
Scientists have long been aware that climate change would not happen at a fixed rate and could include periods where temperatures remain stable for 10 to 20 years, but admitted they had failed to explain this to the public in the past.