Australasian Science: Australia's authority on science since 1938

World Temperature Could Rise 1.5°C by 2020

Global warming could occur more quickly than expected, according to modelling published in PLoS One (

The model, developed by Prof Ben Hankamer of The University of Queensland’s Institute for Molecular Bioscience and Dr Liam Wagner of Griffith University, forecasts that population and economic growth combined with rising energy use per person could significantly increase global energy demand and CO2 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 efficiency 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 efficiency alone don’t offset the surge in energy use per person,” he said. “Simply put, as we get more efficient at manufacturing, 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.”