Greenhouse gas emissions are at the highest they have been in 800,000 years with recent increases mostly due to the burning of fossil fuels, according to the United Nations Intergovernmental Panel on Climate Change (IPCC) which released its synthesis report this week.
The Synthesis Report distils and integrates the findings of the IPCC Fifth Assessment Report produced by over 800 scientists making it the most comprehensive assessment of climate change ever undertaken.
“We have the means to limit climate change,” said R. K. Pachauri, Chair of the IPCC. “The solutions are many and allow for continued economic and human development. All we need is the will to change, which we trust will be motivated by knowledge and an understanding of the science of climate change.”
The report confirms scientists' views that Australia is among the regions of the world already experiencing more extreme weather as the climate warms up, such as more intense heatwaves.
"Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems," the report said.
"Limiting climate change would require substantial and sustained reductions in greenhouse gas emissions which, together with adaptation, can limit climate change risks."
It also said most of the world's electricity should be produced from low carbon sources by 2050 and that fossil fuel burning for power should be virtually stopped by the end of the century.
The IPCC's new report looks at many ways greenhouse gas emissions could evolve this century. Only pathways which see the concentration of greenhouse gases in the atmosphere stabilise at 430 to 480 parts per million give us a likely chance of staying below two degrees, the report says.
In calculations like these, greenhouse gas concentration is expressed as carbon dioxide equivalent (CO2eq), which is a way of including all greenhouse gases, not just carbon dioxide. In an IPCC context, the term "likely" refers specifically to a probability of 66 to 100 per cent.
In 2011, we'd already reached 430 ppm - and emissions are accelerating., the report notes. On current trends, the IPCC estimates we'd exceed 450 ppm by 2030.
But that's not a foregone conclusion. It's still possible to stay below two degrees, but only with rapid cuts to emissions. Globally, emissions need to come down by 40 to 70 per cent by 2050, and all the way down to zero by 2100, the report notes.
Responding to the report yesterday, Australia's Environment Minister, Greg Hunt, admitted "we can all do more" to reduce emissions.
"But we have to do this step by step, instead of big talk and just an electricity tax. I would rather have outcomes [and] achieve what we said we'd do," he said.
Hunt said the IPCC's report vindicated the government's Direct Action policy passed by the Senate last week, with the help of the Palmer United Party.
"It reaffirms precisely why we have taken the action we have," he said.
"What we have to focus on is reducing emissions and the best thing that we can do is clean up existing power stations."
Greens leader Christine Milne said the world had to choose between coal and renewable energies and there was only one viable option
"The world cannot have coal and renewable energy – coal has to go," Senator Milne said adding that Direct Action is a sham.
"The policy is just a front for the protection racket [Prime Minister] Tony Abbott is running for his mates in the fossil fuel sector," Milne said.
"Coal means global warming and that is not good for humanity or the planet. The Greens will do everything possible to phase it out."
