Environment Counts | IPCC report on limiting warming to 1.5Â°C and geoengineering :
The United Nations Intergovernmental Panel on Climate Change (IPCC) has accepted the invitation from the United Nations Framework Convention on Climate Change (UNFCCC) to develop a Special Report on 1.5Â°C. A proposed five chapter outline was approved at the UNFCCC meeting in Nairobi, Kenya, 11 – 13 April 2016. The report is expected to be completed by 2018.
Realistically the world will have only two choices if it wants to stay below 1.5 Â°C of warming. It must either deploy carbon dioxide removal on an enormous scale using as yet unknown technology or use solar geoengineering. Solar engineering involves blocking out a small amount of the incoming sunlight by injecting aerosols into the atmosphere – effectively simulating a massive volcanic eruption. The idea of using solar geoengineering is receiving growing attention because it is the only known way to quickly slow, stop or even reverse global temperature rises.
Chapter 4 of the IPCC’s Special Report on 1.5Â°C outline is called “Strengthening and implementing the global response to the threat of climate change” and looks at how to strengthen and implement the global response to the threat of climate change. This includes
- Assessing current and emerging adaptation and mitigation options, including negative emission methodologies, and associated opportunities and challenges.
- Synergies, trade-offs and integration of adaptation and mitigation options
- The pace of the development and deployment of adaptation and mitigation options compared to pathways consistent with sustainable development and 1.5Â°C
- The potential and capacity limitations for development and deployment of adaptation and mitigation responses to accelerate transitions within and across scales and systems (e.g. food production, cities)
- Options for implementing far-reaching and rapid change; implications, challenges (e.g. lock in, spillover effects), enabling environments and across scales
- Case studies for implementation of adaptation and mitigation options at different scales and circumstances, and lessons learned
Of the two geoengineering options for limiting warming, only removing CO2 from the atmosphere is explicitly mentioned. Negative emissions refers technologies for removing CO2 from the atmosphere and includes direct air capture, cloud treatment to increase alkalinity which enhances dissolving CO2 in water, enhanced weathering, enhanced ocean productivity by adding iron or nitrogen, conservation and restoration of degraded coastal and marine habitats, afforestation and reforestation, bioenergy with carbon capture and storage, building with biomass, biochar, and soil carbon sequestration.
It will be interesting to see if and how the IPCC addresses solar geoengineering in the Special Report on 1.5 Â°C and then in the upcoming broader Sixth Assessment Report (AR6).