The longer nations such as Australia wait to implement substantial climate change mitigation activities, the more expensive it will be to manage its impacts, according to the final part of the Intergovernmental Panel on Climate Change’s Fifth Assessment Report.
The Synthesis Report, which was released on the weekend, shows that adaptation and mitigation activities undertaken now will both create new opportunities and also slow the magnitude of global warming, creating more time for the transition to a low-carbon economy.
“Adaptation can play a key role in decreasing these risks,” Vicente Barros, co-chair of IPCC Working Group II said.
“Adaptation is so important because it can be integrated with the pursuit of development, and can help prepare for the risks to which we are already committed by past emissions and existing infrastructure.”
But the experts stress that adaptation alone is not enough and that substantial and sustained reductions of greenhouse gas emissions are required to limit the risks of climate change
The report finds that the more human activity disrupts the climate, the greater the risks, as continued emissions of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of widespread and profound impacts affecting all levels of society and the natural world.
“We have the means to limit climate change,” said RK 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.”
With the impact of climate change falling disproportionally on the developing nations that have contributed the least to global greenhouse emissions, the IPCC chair stressed that international cooperation is paramount.
“Addressing climate change will not be possible if individual agents advance their own interests independently; it can only be achieved through cooperative responses, including international cooperation,” Mr Pachauri said.
The report finds that there are multiple mitigation pathways to achieve the substantial emissions reductions necessary over the next few decades to limit the warming to two degrees Celsius – the goal set by governments, with a greater than 66 per cent chance.
However, the report finds that delaying additional mitigation to 2030 will substantially increase the technological, economic, social and institutional challenges associated with limiting the warming over the 21st century.
“It is technically feasible to transition to a low-carbon economy,” Youba Sokona, co-chair of IPCC Working Group III said.
“But what is lacking are appropriate policies and institutions. The longer we wait to take action, the more it will cost to adapt and mitigate climate change.”
The latest report finds that mitigation cost estimates vary, but that global economic growth would not be strongly affected. In business-as-usual scenarios, consumption – a proxy for economic growth – grows by 1.6 to 3 per cent a year over the 21st century. Ambitious mitigation would reduce this by about 0.06 percentage points.
“Compared to the imminent risk of irreversible climate change impacts, the risks of mitigation are manageable” the IPPC said.
These economic estimates of mitigation costs do not account for the benefits of reduced climate change, nor do they account for the numerous co-benefits associated with human health, livelihoods, and development.
“The scientific case for prioritising action on climate change is clearer than ever,” Mr Pachauri said. “We have little time before the window of opportunity to stay within 2°C of warming closes. To keep a good chance of staying below 2°C, and at manageable costs, our emissions should drop by 40 to 70 per cent globally between 2010 and 2050, falling to zero or below by 2100. We have that opportunity, and the choice is in our hands.”
- Read or download the IPCC Synthesis Report here