UN climate report calls for zero emissions by end of century
Delegates from 195 nations on Sunday signed off on a UN climate report calling for a 40 to 70 percent drop in emissions in the next 40 years relative to 2010 levels, with a move to zero by the end of the century, in order to avoid the far-ranging and disastrous consequences of climate change.
The report, released by the Intergovernmental Panel on Climate Change (IPCC), also warns that while climate change poses a serious threat to sustainable development, a number of options and opportunities exist to link mitigation and adaptation policies in the pursuit of other societal objectives through integrated responses.
The window for doing so, however, is closing fast and delayed action will hike up future costs of dealing with climate change.
“Strategies and actions can be pursued now which will move towards climate-resilient pathways for sustainable development, while at the same time helping to improve livelihoods, social and economic well-being, and effective environmental management,” a 40-page summary of the IPCC report advises.
The latest offering from UN climate scientists, Sunday’s report summarises more than 5000 pages of analysis on the science, impacts, and action required around climate change, which have been released in three instalments over the last 14 months.
Rajendra Pachauri, chair of the UN panel that released the report, said it was intended as a “roadmap” towards securing a global emissions-cutting deal by the end of next year under the banner of the UN Framework Convention on Climate Change (UNFCCC).
Since 1990, the IPCC has periodically issued weighty assessments on the state of the climate, and mankind’s impact in this area. The Fifth Assessment Report (AR5) announces the starkest climate warnings yet, suggesting that there is a 95 percent probability that global climate change is primarily influenced by human activity.
The report admits to short-term variations in average earth temperatures but cautions that the warming of the climate system is overall unequivocal. In addition, many observed changes in the last fifty years are unprecedented over decades to millennia.
“With this latest report, science has spoken yet again and with much more clarity. Time is not on our side… leaders must act,” said UN Secretary-General Ban Ki-moon, who helped to launch the AR5 synthesis report this past weekend in Copenhagen, Denmark.
The synthesis repeats observations made in the section released at the end of March, which found that climate change had already left its mark on all regions and oceans, and that future climate-related hazards would include flooding, melting glaciers, heatwaves, as well as compromised food and water security. Those most affected would include the world’s poorest. (See BioRes, 2 April 2014)
Material from the final instalment released in April also features in the summary, with particularly strong messages on the contribution of fossil fuel combustion to an overall ballooning of emissions, a fundamental driver of global warming and climate change. (See BioRes, 14 April 2014)
According to the synthesis report, total carbon dioxide emissions from fossil fuels and cement production have tripled since 1970, while those from forestry and other land use have climbed by around 40 percent in the same period.
Confirming previous analysis, Sunday’s summary reiterates that ambitious climate mitigation policy would shave 0.06 percent off average annual global consumption over the century. This figures does not account for variations between regions nor the potential positive externalities, such as improved air quality.
Transitioning to a low-carbon economy would require significant changes in investment patterns. In a bid to provide clarity as to the structural shift required, the IPCC in AR5 details a carbon budget for the first time, suggesting that a maximum 2900 billion tonnes of carbon dioxide can be emitted if planetary warming is to stay below two degrees Celsius relative to pre-industrial levels.
The report warns that by 2011 two-thirds of the carbon budget had already been spent and that emissions have continued since then at around 38 billion tonnes a year.
Renewable energy sources have climbed in recent years, accounting for 56 percent of net additions to the global energy mix in 2013 according to a report by REN21, which describes itself as a global renewable energy policy multi-stakeholder network. However, some energy companies continue to pump cash into long-term fossil fuel projects, and a number of governments maintain fossil fuel subsidies.
Some UN climate scientists have said that the absence of carbon budget and allocation discussion from ongoing multilateral climate talks is problematic, as this discussion could help send appropriate market signals. The most recent round of negotiations in October saw delegates focus on detailing national contributions to an overall package. (See BioRes, 3 November 2014)
“If they choose not to talk about the carbon budget, they’re choosing not to address the problem of climate change,” said Myles R. Allen, a climate scientist from Oxford University who helped pen the synthesis report, in an interview with The New York Times.
The share of global low-carbon electricity supply, including renewable energy, nuclear, and carbon capture and storage – a process that traps and stows away climate-warming emissions – will need to increase from current levels of 30 percent to more than 80 percent by 2050 in order to stay within the two degree limit.
Some discord on this warming threshold, agreed to by world leaders in 2010 at the climate meet held in Durban, South Africa, has begun to surface as of late. A number of developing countries, particularly coastal and island economies, have said that a two degree increase is far too high when climate change is already causing communities to relocate in the face of rising sea levels.
A new feature of Sunday’s report is analysis on how to stay below a 1.5 degree warming threshold, which would require emissions reductions of between 70 and 95 percent from 2010 levels by mid-century.
The report also re-emphasises that no single policy will be able to address climate change. Instead a range of mitigation and adaptation tools will be required and should be implemented at various scales including international, regional, national, and sub-national.
ICTSD reporting; “U.N. Panel Issues Its Starkest Warning Yet on Global Warming,” THE NEW YORK TIMES, 2 November 2014; “Climate change fight affordable, cut emissions to zero by 2100 – UN,” REUTERS, 2 November 2014; “Special Briefing, The Intergovernmental Panel on Climate Change report,” CARBON BRIEF, 3 November 2014.