Meeting in Bangkok this week, the Intergovernmental Panel on Climate Change approved the outline for its upcoming report on the impacts of global warming of 1.5 degrees Celsius above preindustrial levels. The IPCC is preparing the report at the request of the United Nations Framework Convention on Climate Change, parties to which pledged in the international Paris Agreement on climate change to try to limit global warming to 1.5 degrees. “We can no longer say that the policy makers are ignoring the voice of science,” IPCC Chair Hoesung Lee said during a press conference Thursday. “They are ready to act, and they need robust science as a basis on which to formulate sound policy. That is where the IPCC comes in.”
The 1.5-degree report will consist of five chapters. The first chapter will address “framing and context” and will present the basics of what a 1.5-degree pathway would mean for the world. Specific topics to be covered in the chapter include: “1.5°C in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty, with consideration for ethics and equity”; and understanding 1.5 degrees Celsius in terms of reference levels, probability, transience, overshoot, and stabilization.
Chapter two, which addresses “mitigation pathways compatible with 1.5°C in the context of sustainable development,” may be difficult for the authors of the report to write, given a lack of scientific literature on the topic, IPCC Vice Chair Thelma Krug, who led the scientific steering committee for the scoping meeting that drafted the outline, said during the press conference. “There is a … absolute concern with the literature being available to address these issues that we indicatively put forward at this meeting,” she said.
The idea of a 1.5-degree future often raises questions regarding the potential need for negative carbon technologies. The world has already warmed by 1 degree over preindustrial levels and making the drastic emissions cuts needed not to exceed the carbon budget for 1.5 degrees may be unreasonable. If the budget is exceeded, negative carbon technologies will likely need to be developed to pull carbon from the atmosphere.
When asked about the potential need for such technology, Krug declined to make assumptions. “We don’t want to prejudge the findings of this report. I think that we have to wait to see what solid literature is out there now,” she said.
The final three chapters cover the potential impacts of 1.5 degrees of global warming on natural and human systems; strengthening and implementing the global response to the threat of climate change; and sustainable development, poverty eradication, and reducing inequalities.
The outline will now be passed to the authors, who will be selected by the IPCC in the next month, to begin their work. The paper will be completed in 2018, according to Lee.