Australasian Science 11

(Jacob Rumans) #1
World Temperature
Could Rise 1.5°C by
2020
Global warming could occur more quickly than
expected, according to modelling published in
PLoS One (tinyurl.com/jm6bbx8).
The model, developed by Prof Ben
Hankamer of The University of Queensland’s
Institute for Molecular Bioscience and Dr Liam
Wagner of Griith University, forecasts that
population and economic growth combined
with rising energy use per person could signii-
cantly increase global energy demand and CO 2
emissions, causing world average temperatures
to rise by 1.5°C as early as 2020.
“Nations at the 2015 UN Conference on
Climate Change agreed to keep the rise in global
average temperature below 2°C, preferably
limiting it to 1.5° to protect island states,”
Hankamer said. “Our model shows we may have
less time left than expected to prevent world
temperature from rising above these thresholds.
“World population is forecast to increase to over nine billion
people by 2050, which, together with international ‘pro-growth’
strategies, will lead to continually increasing energy demand.”
Wagner said that the model challenged the assumption that
increases in energy eiciency and conversion would offset increases
in demand. “We have successfully applied our model to world
energy demand from 1950–2010, and demonstrated that increases
in energy eiciency alone don’t offset the surge in energy use per
person,” he said. “Simply put, as we get more eicient at manu-

facturing, goods get cheaper and we buy more.”
Furthermore, Wagner warned that massive increases in energy
consumption would be necessary to alleviate poverty for nearly
50% of the world’s population who live on less than $2.50 per
day. “We have a choice: leave people in poverty and speed towards
dangerous global warming through the increased use of fossil fuels,
or transition rapidly to renewables,” he said. “As 80% of world
energy is used as fuels and only 20% as electricity, renewable fuels
in particular will be critical.”

6 | APRIL 2016


The past 16 record-breaking hot years globally have removed the
doubts of world leaders about the influence of human-caused climate
change, but the first signs appear as far back as 1937 according to
research published in Geophysical Research Letters(tinyurl.com/
jc5rh6n).
“Globally, all the record-breaking hot years we’ve had since the
1990s are so much outside natural variability that they would be
almost impossible without climate change caused by humans,” said
lead author Dr Andrew King of the ARC Centre of Excellence for
Climate System Science.
“In Australia, our research showed the last six record-breaking hot
years and last three record-breaking hot summers were made much
more likely due to global warming,” King said. “We were able to see
climate change more clearly in Australia because of its position in the
Southern Hemisphere in the middle of the ocean, far away from the
cooling influence of high concentrations of industrial aerosols.”
Previous research has shown that aerosols in high concentrations
over specific regions had a cooling effect, reflecting more heat back
into space. However, warming returned rapidly when those aerosols
were removed from the atmosphere.

Cooling periods, likely caused by aerosols, occurred in Central
England, Central US, Central Europe and East Asia during the 1960s
and 1970s before accelerated warming returned. These heightened
aerosol concentrations also delayed the emergence of a clear human-
caused climate change signal in all regions studied except Australia.
“In regards to a regional human-caused climate change signal,
Australia was the canary in the coal mine for the rest of the world. The
signal appeared there first and then, over the coming years, it became
apparent elsewhere,” King said.
“Recent increases in aerosols over East Asia has started to slow
the rise in the number of the region’s record hot years and summers,
again masking the clear climate change signal we are finding in other
areas. High aerosol concentrations also significantly delayed the
climate signal in the Central US.”
“The key now is to determine how much warmer the climate will
continue to get so we can respond to the impacts this will inevitably
bring,” said King. “This is particularly true for Australia, which appears
to have one of the strongest climate change signals for a populated
country. As a nation, it will need to respond more quickly and
understand clearly what future climate change brings.”

Anthopogenic Warming Goes Back to the 1930s


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