Global temperature records set in
2015 – the hottest year so far – may become the new norm by 2025 if carbon
emissions continue to rise at the same rate. Human activities have already
locked in this new ‘normal’ for future temperatures but immediate climate action
could prevent record extreme seasons year after year. If we don’t reduce our
rate of emissions, the record hot summer of 2013 in Australia - when we saw
temperatures approaching 50 degrees Celsius in some areas – could be just
another average summer season by 2035. So, what is the idea of a new normal? Researchers
determined that a new normal occurred when at least half of the years following
an extreme year were cooler and half warmer. Only then can a new normal state
be declared. This process was also used to determine new normal conditions for
seasonal and regional changes to the climate. Using the ANU’s National
Computational Infrastructure supercomputer to run climate models, the
researchers explored when new normal states would appear under the
Intergovernmental Panel for Climate Change’s four emissions pathways. The results
revealed that while global average temperatures would inevitably enter a new
normal under all emissions scenarios, this was not the case at seasonal and
regional levels. Researchers 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.
No comments:
Post a Comment