ODP: The IPCC’s report this week focused on land — with a particular focus on desertification, land degradation and food security — why?
JL: Land is a really important part of the climate system and governments wanted to take a deeper look at how our land is being affected by climate change and conversely how our use of land affects the climate. Because it’s been 19 years since the last Special Report on Climate Change and Land Use, Land Use Change and Forestry (LULUCF), a number of governments submitted proposals for a new report on a variety of different land-related issues. The IPCC brought these suggestions together and made a proposal for this broader special report, the full title of which is the “Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems.”
ODP: People think of global warming as being caused by pollution of gasses like CO2 into the air — how does land use contribute to it?
JL: There is a complex interaction between land and climate. Earth’s land systems naturally absorb and store greenhouse gases (GHGs). Land also releases greenhouse gases into the atmosphere, depending on how it’s used. Since carbon is stored in the land, when land use is changed (e.g., degraded, restored or converted to agriculture) it can increase or decrease those emissions. This is how land use contributes to global warming. There are some land-use changes that contribute to global warming more than others.
ODP: How many scientists and from how many countries worked on this report and how did they reach consensus?
JL: There were 107 authors that contributed to this report from 52 different countries, with 53% of authors coming from developing countries. This is the first time that a majority of authors were from developing countries. Similarly, this is the first time that 40% of the chapter lead authors were female. All authors volunteer their time for this process. They work together in chapter teams to reach a balanced and comprehensive assessment of the scientific literature they are assessing. They prepare several drafts of the report each of which is revised in light of comments received by experts and governments. The final stage is governments consider the Summary for Policymakers prepared by the authors and approve it for clarity and ensuring consistency with the full report. Governments must reach consensus among themselves and the scientists have the last word on any changes.
ODP: Will the Report contain options for what to do to address the findings or recommend a course of action for the world to take?
JL: The IPCC does not tell policymakers what to do or make specific recommendations, but the reports are designed to be relevant to policymakers. IPCC reports layout sets of options to address different climate-related concerns and look at tradeoffs between different options to help with decision making.
ODP: What is next for the IPCC? Where do they go from here?
JL: This is the second of a series of 3 special reports, and follows the Special Report on Global Warming of 1.5C released in October of 2018. Next month, the IPCC will finalize and release the Special Report on the Ocean and Cryosphere in a Changing Climate.
Thanks, Jonathan. We will be very interested in the upcoming oceans report next month so keep us posted.