Extreme weather events set to rise
Extremely hot and cold spells have become more common around the world over the last three decades, scientists have said.
Researchers at the University of East Anglia (UEA) in Norwich analysed temperature records between 1881 and 2013 and found that extreme events at either end of the spectrum were increasing.
Over the 130-year period, the occurrence of unusually cold periods had been increasing at a faster rate than hot anomalies.
But in the last 30 years, that pattern reversed with extreme warm weather events increasing more quickly.
This shows that the Earth's temperature was becoming more homogeneous with time, but this trend has recently reversed, the researchers said.
Temperatures were also considerably more volatile in the Northern Hemisphere than in the Southern Hemisphere, probably because there is less land mass in the south to complicate weather systems.
The findings come after the UEA said that 2014 is on track to be the warmest year on record.
Phil Jones, from the university's climatic research unit, said: "Trends in extreme heat and cold are important because they have a large impact on water supplies, agricultural productivity and other factors related to human health and wellbeing.
"Improved understanding of the spatial patterns of change are vital for understanding the causes of recent extreme weather events."
Scott Robeson, from Indiana University in the US which also took part in the study, said this information could be more useful than looking at average temperatures.
He added: "Arguably, these cold extremes and warm extremes are the most important factors for human society."
Scientists had previously observed a pause in global warming since 1998 based on average temperatures.
But this study found that warming continued in most parts of the planet but that warming was offset by a strong cooling during the winter months in the Northern Hemisphere.
Prof Robeson said: "There really hasn't been a pause in global warming. There has been a pause in Northern Hemisphere winter warming."
It comes after a Met Office study found that t he chances of heatwaves in Europe have dramatically increased in the past decade as a result of warming temperatures.
The chances of extreme heatwaves, such as the one in 2003 which led to tens of thousands of deaths across Europe, have also increased tenfold, from a one in 1,000 year event to around once in a century.
By the 2040s, such extreme heatwaves could happen every other year if greenhouse gas emissions continue to rise, the research published in the journal Nature Climate Change found.