The warmest global temperatures on record for 2015 might be just an average year by 2025 if greenhouse gas emissions carry on rising at their current pace, according to new study published in the Bulletin of American Meteorological Society.
Regardless of any preventative actions, we are already stuck in a “new normal” for global average temperatures that would kick in no later than 2040, the study said.
However, while average global average temperatures were locked in, quick and strong action on carbon emissions could keep record breaking heat in summers and winters from becoming average at local levels.
“If we continue with business-as-usual emissions, extreme seasons will inevitably become the norm within decades and Australia will be the canary in the coal mine that will experience this change first,” Sophie Lewis, from the Australian National University (ANU), said in a news release. “That means the record hot summer of 2013 in Australia – when we saw temperatures approaching 50°C (122 degrees F) in parts of Australia, bushfires striking the Blue Mountains in October, major impacts to our health and infrastructure and a summer that was so hot it became known as the ‘angry summer’ – could be just another average summer season by 2035.”
Have we reached a “new normal”?
The study team said the primary goal of their research was to define ‘new normal’ – a term thrown around a lot when talking about climate change. The researchers said this term isn’t well defined, and the study aimed to put a scientific foundation underneath it.
“Based on a specific starting point, we determined a new normal occurred when at least half of the years following a record year were cooler and half warmer. Only then can a new normal state be declared,” Lewis said.
Using climate models, the scientists investigated when new normal states would crop up under the Intergovernmental Panel for Climate Change’s four emissions scenarios. The study team then evaluated seasonal temperatures from December to February for Australia, Europe, Asia and North America.
The outcomes showed that while global average temperatures would undoubtedly switch over to a new normal under all four scenarios, this wasn’t the situation at seasonal and local amounts.
“It gives us hope to know that if we act quickly to reduce greenhouse gasses, seasonal extremes might never enter a new normal state in the 21st Century at regional levels for the Southern Hemisphere summer and Northern Hemisphere winter,” Lewis said. “But if we don’t act quickly Australia’s “angry summer” of 2013 may soon be regarded as mild.”
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