Heatwaves in England 13 times more likely today

England is thirteen times more likely to have a heatwave today compared to 100 years ago. Human-induced climate change will affect England’s weather more than most other countries, with record-breaking hot summers like in 2014 occurring much more frequently, says a team of scientists from the US, the Netherlands and Australia.

England registered its warmest year ever in 2014. Climate scientists, led by Dr. Andrew King from the the ARC Centre of Excellence for Climate System Science at the University of Melbourne, Australia, reported in the academic journal Environmental Research Letters that England today is far more likely to have a record-breaking hot year because of anthropogenic (human-induced) climate change.

The researchers reached their conclusions after analyzing a series of climate model simulations from information obtained from the Central England Temperature (CET) record – which dates back to 1659 and is the world’s oldest instrumental temperature record.

The rectangle marks the Central England area. The black crosses show the locations of stations used in the calculation of the CET at some time from 1659 to the present day. (Image: cdn.iopscience.com)

Dr. King and colleagues said they were surprised at how England, a relatively small country, could be so precisely targetted by human-induced climate change.

Comparing large and small areas

Dr. King commented:

“When you look at average annual temperatures over larger regions of the world, such as the whole of Europe, there is a lower variability in temperatures from year to year compared with smaller areas.”

 

“As a result of this low variability, it is easier to spot anomalies. This is why larger regions tend to produce stronger attribution statements, so it is remarkable that we get such a clear anthropogenic influence on temperatures in a relatively small area across central England.”

The researchers compared model simulations which gauged the probability of super-hot years with just natural forcings on climate and no influence of human activity, against what could occur when human influence and natural forcings were combined.

They then calculated what the impact of human activity would be on the probability of record-warm years.

The authors then studied the CET data and selected the hottest years in central England from the records since 1900, and plotted those years onto a graph. With this information, they calculated the probability of very-hot years occurring now compared to 100 years ago.

Super-hot years 13 times more likely today

According to a model-based study, central England today is 13 times more likely to have a record-breaking hot year due to human influences on the climate compared to 100 years ago, the authors reported.

“The observation-based approach suggested at least a 22-fold increase in the probability of very warm years in the climate of today compared with the climate of a century ago (again with 90% confidence),” they added.

Millions of Brits will probably welcome these record-hot years.

Dr. King said:

“Both of our approaches showed that there is a significant and substantial increase in the likelihood of very warm years occurring in central England.”

According to CET data, 2014 was central England’s hottest year ever.

Reports indicate that over the last six decades there has been rapid warming in central England, in line with human-activity’s influence on the climate. For the whole of 2014, the average temperature was 10.93°C.

The Central England Temperature (CET) database is the oldest instrumental series of temperatures globally. Average daily and monthly recordings date back to 1772 and 1659 respectively.

The CET represents the climate of a triangular area in the English Midlands, enclosed by Lancashire in the north, London in the south-east, and Bristol in the south-west.

The CET, which has undergone thorough and extensive quality control, is an ideal resource for studying long-term climate trends across the region.

What about the rest of the country?

Will the rest of the UK be more likely to register record-breaking hot years?

Dr. King said:

“I would expect that other areas near the UK would produce similar results.”

“For larger regions, stronger attribution statements can often be made. For example, we performed a similar attribution study for Europe as a whole and found a 35-fold increase in the likelihood of extremely warm years using model simulations.”

In the journal, the authors concluded:

“Overall, this study provides substantial evidence to suggest that the anthropogenic influence on the climate has significantly increased the likelihood of warm years in Central England.”

Reference: “Attribution of the record high Central England temperature of 2014 to anthropogenic influences,” Andrew D King, David J Karoly, Geert Jan van Oldenborgh, Sophie C Lewis and Heidi Cullen. Environmental Research Lettter. Published 1 May, 2015. DOI: 10.1088/1748-9326/10/5/054002.

Video – Record hot temperatures Central England