The Paris Agreement on climate change, adopted in December 2015 and signed on 22 April 2016 by over 170 nations, represented a commitment to limit global warming to 2oC, with an effort to pursue 1.5oC where possible. Six months on from adoption, the challenge of implementing these goals has begun. What do we need to know to get there?
- How can we improve predictions of regional and decadal climate change?
While there is much emphasis on global change, better regional predictions are crucial. Improvements will rely on better understanding of the climate dynamics that control major variability (e.g. teleconnections, storm tracks etc.) and the impact on the hydrological cycle. Extreme weather events drive much of the cost of climate change and understanding regional variability more would improve our understanding of extremes in the past and into the future.
- How can we ensure carbon budgets enable the desired global temperature targets?
Despite a global agreement on limiting global temperature rise, carbon budgets (the amount of greenhouse gases that can be emitted without exceeding a certain temperature) need to be defined with more certainty to provide actionable targets for climate change mitigation pathways. Cloud processes and large uncertainties in the land carbon cycle, the N cycles, peatland carbon, permafrost and vegetation need to be understood better through a combination of data and models.
Shorter term gains also need to be taken into consideration when planning for future emissions scenarios. For example how can air quality and climate be balanced, and what are the societal implications of limiting agricultural emissions of methane?
- How can we mitigate climate change as well as other long term problems?
Continued sea level change and acidification of the ocean are inevitable. The potential for very significant sea level rises due to destabilisation of the Antarctic and/or Greenland ice sheets is more distant, but worrying because of its irreversibility. How will we manage mitigating climate change as well as sea level rise and ocean acidification, all under different timescales.
- Need for Negative emissions?
The current global temperature targets imply rapid mitigation and will likely need to include negative emissions methods. These methods however come with engineering questions that need to be answered as well as the wider costs, benefits and risks to society.
This meeting was part of the Global Environmental Research Committee’s series of reviews on important topics within global environmental research (such as biodiversity, natural resources and oceans etc.). The Global Environmental Research Committee provides advice to the Royal Society, while interacting with research councils, the environmental science community and other bodies, including UK Future Earth, highlighting trends that will inform future activity and research.
Henry Webber was a Royal Society, Arts and Humanities Research Council, Intern who is currently undertaking a PhD at the University of Bristol and University of Reading.