Extreme temperatures at risk of becoming the new normal

Australian researchers have found that the year 2015, currently listed as the hottest year on record, could be an average year by 2040 if carbon emissions continue to rise at the same rate. This is according to research led by the ARC Centre of Excellence for Climate System Science and published in the Bulletin of the American Meteorological Society.

The idea of a new normal when talking about climate change had never been clearly defined until the research team developed a scientific definition for the term. According to lead author Dr Sophie Lewis, “Based on a specific starting point, we determined a new normal occurred when at least half of the years following an extreme year were cooler and half warmer.”

Using the National Computational Infrastructure supercomputer at The Australian National University (ANU) to run climate models, the researchers explored when new normal states would appear under the Intergovernmental Panel on Climate Change’s four emissions pathways, examining seasonal temperatures from December to February across Australia, Europe, Asia and North America.

According to Dr Lewis, human activities have already locked in this new normal for future temperatures. She said, “If we don’t reduce our rate of emissions, the record hot summer of 2013 in Australia — when we saw temperatures approaching 50°C in some areas — could be just another average summer season by 2035.”

However, Dr Lewis added that immediate climate action could prevent record extreme seasons year after year. She said, “The results revealed that while global average temperatures would inevitably enter a new normal under all emissions scenarios, this wasn’t the case at seasonal and regional levels.

“We found that with prompt action to reduce greenhouse gases, a new normal might never occur in the 21st century at regional levels during the Southern Hemisphere summer and Northern Hemisphere winter.”

As part of its own emissions reduction efforts, ANU today opened its new X-ray microscopy laboratory, following a $5 million upgrade to help store carbon dioxide underground. The renovated CTLab was funded by the CO2CRC and the Australian Government’s Education Investment Fund, and is part of the $51.6 million Australian CCS Research Laboratories Network (CCSNET).

The lab now houses equipment including X-ray microscopes which scientists can use to observe carbon dioxide being trapped in aquifer rocks. Its new facilities will enable ANU scientists to build accurate large-scale computer models explaining how complex layers of sedimentary rock influence the effectiveness of carbon dioxide storage.

“Secure storage of the carbon dioxide depends on interactions between salty groundwater and the injected carbon dioxide within microscopic gaps in the underground rocks,” said Associate Professor Adrian Sheppard, head of the Department of Applied Mathematics at ANU. “Our 3D microscopes give us an unprecedented ability to observe these interactions directly.”

Tania Constable, CEO of CO2CRC, said the CCSNET laboratories are part of an interconnected set of assets in Australia that will reduce the cost of carbon capture and storage while ensuring long-term safety.

“The ANU assets, as well as others around Australia, will provide vital workflows, data and technologies that are relevant to flagship carbon capture and storage projects locally and internationally,” she said.

“If we are to have any chance of achieving Australia’s emissions reduction targets we’ll need to implement a range of responses: renewable energy, greater energy efficiency, fuel switching and the use of carbon capture and storage as the major technology to curb industrial emissions.”