Natural climate solutions, Griscom 2017

This is one of the most comprehensive mainstream studies to date of a broad spectrum of natural climate solutions by thirty-two co-authors and supported by The Nature Conservancy. The report examines “20 conservation, restoration, and/or improved land management actions that increase carbon storage and/or avoid greenhouse gas emissions across global forests, wetlands, grasslands, and agricultural lands.”  The authors “find that the maximum potential of NCS [Natural Climate Solutions] —when constrained by food security, fiber security, and biodiversity conservation—is 23.8 petagrams^[11] of CO2 equivalent . . . This is ≥30% higher than prior estimates, which did not include the full range of options and safeguards considered here.” [Griscom 2017: 11645].  The study seeks to assess both the potential emissions from land use as well as the carbon-sequestration potential.

The study posits a target of <2o C as the conventionally agreed-upon safe limit:

Warming will likely be held to below 2 °C if natural pathways are implemented at cost-effective levels . . . and if we avoid increases in fossil fuel emissions for 10 y and then drive them down to 7% of current levels by 2050 and then to zero by 2095 [p. 11647]

The authors state that their estimates are intentionally conservative because (1) they do not include potential benefits of payments for high-money-value ecosystem services in stimulating NCS efforts; (2) they exclude various management practices where data were not “sufficiently robust for global extrapolation,” e.g., no-till, adaptive multi-paddock grazing, etc.; and (3) significant additional investment would be required to keep warming at 1.5o C. [Griscom 2017: 11648]

Detail is provided on contributions of specific mitigation pathways, such as forests, wetlands, grasslands, etc., and on challenges as well.  For example, “Despite the large potential of NCS, land-based sequestration efforts receive only about 2.5% of climate mitigation dollars.” [Griscom 2017: 11648] This observation is consistent with our observations of limited available resources for the most basic NCS education. Other challenges include deforestation for farming and animal husbandry, losing high carbon sequestration benefits of wetlands due to reclamation, and impacts of climate feedbacks such as fire, drought, temperature increases, etc.

We applaud Griscom et al. for an excellent and comprehensive analysis and review of many of the factors in natural climate solutions. We do, however, believe that (1) the potential of nature’s solutions is far greater than Griscom et al. estimate, and (2) that the temperature limits (1.5o – 2o C) are too high and too dangerous – considering that natural processes are already changing, drastically and for the worse, with an average global temperature increase of barely 1o C (see Appendix A: Urgency of the Biodiversity and Climate Crisis).

The differences between the perspectives of Griscom et al. and those adopted in this Compendium are paradigmatic.  Griscom et al. acknowledges that their estimates are conservative, looks at a set of studies that tends toward the mainstream and is primarily based on established and widespread practice. This is perfectly reasonable in the process of what Thomas Kuhn calls “normal science” (see Compendium Vol. 1 No. 1 for an extensive discussion of Kuhn’s landmark work). Unfortunately the process of normal science for accepting new thinking and discoveries usually takes decades, and we are currently in the throes of an extinction, and an emergency with respect to biodiversity, and climate change. Therefore we have to accelerate our response.  Accordingly, Bio4Climate searches for studies that tend to examine positive variants, i.e., examples of what is possible beyond current conceptual boundaries.  We emphasize goals to strive for, even if the data are not yet “sufficiently robust for global extrapolation.” The robustness of such data will increase with more intentional focus.

An interesting side effect of the paradigm difference is that numerous sources that we cite, many from the scientific literature, don’t appear in NCS references (for example, Richard Teague [Teague et al. 2016], Gabe Brown [Brown 2016], Tom Goreau [Goreau 2015], Rebecca Ryals and Whendee Silver [Ryals and Silver 2013], David Johnson [Johnson 2017], Paul and Elizabeth Kaiser [Kaiser 2017], Terry McCosker [McCosker 2000], Carol Evans and Jon Griggs [Evans et al., 2015], to name just a few). Nor are there discussions of permaculture or agroforestry, two of the more promising areas of research and practice in land management that lead to climate-positive results.