Bronson W. Griscom

The Nature Conservancy · Climate

Carbon dioxide removal (CDR) figures prominently in modelled pathways to achieve the Paris Agreement's goal of limiting global warming to 1.5-2°C compared to pre-industrial levels. However, national roles and responsibilities to deliver CDR have been informed with CDR quota analyses that focus on developed economies and global major emitters. This...

Nature‐based efforts could further climate mitigation and help limit warming to 1.5°C, given that proper and immediate solutions are implemented with similar ambition as in energy and industry sectors; however, omission of natural solutions or delays in overall climate action would substantially undermine the climate target of Paris Agreement.

Huge areas of tropical forests are degraded, reducing their biodiversity, carbon, and timber value. The recovery of these degraded forests can be significantly inhibited by climbing plants such as lianas. Removal of super-abundant climbers thus represents a restoration action with huge potential for application across the tropics. While experimenta...

For monitoring and reporting forest carbon stocks and fluxes, many countries in the tropics and subtropics rely on default values of forest aboveground biomass (AGB) from the Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas (GHG) Inventories. Default IPCC forest AGB values originated from 2006, and are relativ...

Limited time and resources remain to constrain the climate crisis. Natural climate solutions represent promising options to protect, manage and restore natural lands for additional climate mitigation, but they differ in (1) the magnitude and (2) immediacy of mitigation potential, as well as (3) cost-effectiveness and (4) the co-benefits they offer....

Land-based climate mitigation measures have gained significant attention and importance in public and private sector climate policies. Building on previous studies, we refine and update the mitigation potentials for 20 land-based measures in >200 countries and five regions, comparing "bottom-up" sectoral estimates with integrated assessment models...

Spatial prioritization is a critical step in conservation planning, a process designed to ensure that limited resources are applied in ways that deliver the highest possible returns for biodiversity and human wellbeing. In practice, many spatial prioritizations fall short of their potential by focusing on places rather than actions, and by using da...

Analysis suggests that to limit global temperature rise, we must slash emissions and invest now to protect, manage and restore ecosystems and land for the future. Analysis suggests that to limit global temperature rise, we must slash emissions and invest now to protect, manage and restore ecosystems and land for the future.

Article Lower cost and more feasible options to restore forest cover in the contiguous United States for climate mitigation Graphical Abstract Highlights d Restoring forest cover in the US can be a cost-effective climate solution d New forest across 51.6 Mha could capture 314 MtCO 2 year À1 d We provide critical information to guide decisions about...

To limit global temperature rise, scientists have proposed significant potentials for climate change mitigation from protecting and managing natural systems (Griscom et al., 2017; Paustian et al., 2016; Roe et al., 2019; Smith et al., 2019). However, we show that the speed at which nature’s power is unleashed is as important as the mitigation poten...

To constrain global warming, we must strongly curtail greenhouse gas emissions and capture excess atmospheric carbon dioxide1,2. Regrowing natural forests is a prominent strategy for capturing additional carbon³, but accurate assessments of its potential are limited by uncertainty and variability in carbon accumulation rates2,3. To assess why and w...

Mitigating climate change requires clean energy and the removal of atmospheric carbon. Building soil carbon is an appealing way to increase carbon sinks and reduce emissions owing to the associated benefits to agriculture. However, the practical implementation of soil carbon climate strategies lags behind the potential, partly because we lack clari...

While improved management of agricultural landscapes is promoted as a promising natural climate solution, available estimates of the mitigation potential are based on coarse assessments of both agricultural extent and aboveground carbon density. Here we combine 30‐meter resolution global maps of aboveground woody carbon, tree cover, and cropland ex...

Avoiding catastrophic climate change requires rapid decarbonization and improved ecosystem stewardship. To achieve the latter, ecosystems should be prioritized by responsiveness to direct, localized action and the magnitude and recoverability of their carbon stores. Here, we show that a range of ecosystems contain ‘irrecoverable carbon’ that is vul...

Better land stewardship is needed to achieve the Paris Agreement's temperature goal, particularly in the tropics, where greenhouse gas emissions from the destruction of ecosystems are largest, and where the potential for additional land carbon storage is greatest. As countries enhance their nationally determined contributions (NDCs) to the Paris Ag...

The Paris Agreement introduced an ambitious goal of limiting warming to 1.5 °C above pre-industrial levels. Here we combine a review of modelled pathways and literature on mitigation strategies, and develop a land-sector roadmap of priority measures and regions that can help to achieve the 1.5 °C temperature goal. Transforming the land sector and d...

Land-based greenhouse gas removal (GGR) options include afforestation or reforestation (AR), wetland restoration, soil carbon sequestration (SCS), biochar, terrestrial enhanced weathering (TEW), and bioenergy with carbon capture and storage (BECCS). We assess the opportunities and risks associated with these options through the lens of their potent...

This is the openly published DATASET relating to the Nature Communications article: Runting, Rebecca, Ruslandi, Ruslandi, Griscom, Bronson, Struebig, Matthew J., Satar, Musnanda, Meijaard, Erik, Burivalova, Zuzuna, Cheyne, Susan M., Deere, Nicolas, Game, Edward, and others. (2019) Larger gains from improved management over sparing–sharing for trop...

Meeting climate mitigation and sustainable development goals requires rapid increases in both renewable energy development and carbon storage in ecosystems. If sited with the sole goal of maximizing production, renewable energy may negatively impact biodiversity and carbon storage. Here, we evaluated the potential unintended environmental consequen...

As countries advance in greenhouse gas (GHG) accounting for climate change mitigation, consistent estimates of aboveground net biomass change (∆AGB) are needed. Countries with limited forest monitoring capabilities in the tropics and subtropics rely on IPCC 2006 default ∆AGB rates, which are values per ecological zone, per continent. Similarly, res...

1.Selective logging in tropical forests changes the local number of animal species (alpha diversity), but it also likely affects species turnover (beta diversity). Whilst such changes are documented in many ecosystems under different disturbances, they are poorly understood in selectively logged tropical forests. 2.By using soundscape recordings ac...

Achieving the 1.5–2.0 °C temperature targets of the Paris climate agreement requires not only reducing emissions of greenhouse gases (GHGs) but also increasing removals of GHGs from the atmosphere [1,2]. Reforestation is a potentially large-scale method for removing CO2 and storing it in the biomass and soils of ecosystems [3,4,5,6,7,8], yet its co...

The selective logging that characterizes most timber extraction operations in the tropics leaves large patches of logging blocks (i. e., areas allocated for harvesting) intact, with no direct impacts of the harvest. For example, in the ~10,000 ha we sampled in 48 forest management enterprises in Africa (Gabon, Republic of Congo, and the Democratic...

The impact of different types of land tenure in areas with high biodiversity and threats of deforestation remains poorly understood. We apply rigorous quasi-experimental methods and detailed geospatial data to assess the role of tenure regimes-communally held lands (specifically, ejidos), private property, and their impact on the effectiveness of p...

Protected vs. unprotected pixels within ejidos–moist broadleaf forests. (DOCX)

Protected vs. unprotected pixels within private properties–dry broadleaf forests. (DOCX)

Covariate balance tables for protected ejido pixels matched to protected private property pixels—Dry broadleaf forest. (DOCX)

Covariate balance tables for unprotected ejido pixels matched to unprotected parceled ejido pixels—Dry broadleaf forest. (DOCX)

Summary of the protected areas on the Yucatan Peninsula. Because protection may necessitate time to effect change, we dropped the protected areas established after 2000 from the analysis. We follow the classification in [11]. (DOCX)

Protected vs. unprotected pixels regardless of tenure–dry broadleaf forests. (DOCX)

Protected vs. unprotected pixels within private properties–moist broadleaf forests. (DOCX)

Covariate balance table for unprotected pixels within protected ejidos matched to observationally similar pixels in unprotected ejidos in dry broadleaf forests. (DOCX)

Covariate balance table for unprotected pixels within protected private properties matched to observationally similar pixels in unprotected private properties in moist broadleaf forests. (DOCX)

Covariate balance tables for protected ejido pixels matched to protected parceled ejido pixels—Moist broadleaf forest. (DOCX)

Variable codes and definitions for the covariate balance tables below. The following tables represent the covariate balances of the matched and unmatched samples for all of the comparisons. The normalized differences are calculated using the formula in [42] and a threshold of 0.25. (DOCX)

Covariate balance table for unprotected pixels within protected private properties matched to observationally similar pixels in unprotected private properties in dry broadleaf forests. (DOCX)

Covariate balance table for unprotected pixels within protected parceled ejidos matched to observationally similar pixels in unprotected parceled ejidos in dry broadleaf forests. (DOCX)

Covariate balance tables for protected ejido pixels matched to protected private property pixels—Moist broadleaf forest. (DOCX)

Covariate balance tables for protected private property pixels and protected parceled ejido pixels—Dry broadleaf forest. Because of the small control pool (n = 32), matching was not possible. (DOCX)

Covariate balance tables for protected private property pixels matched to protected parceled ejido pixels—Moist broadleaf forest. (DOCX)

Covariate balance tables for unprotected parcelized ejido pixels matched to unprotected private property pixels—Moist broadleaf forest. (DOCX)

Protected vs. unprotected pixels regardless of tenure–moist broadleaf forests. (DOCX)

Protected vs. unprotected pixels within parcelized ejidos–moist broadleaf forests. (DOCX)

Covariate balance table for unprotected pixels within protected ejidos matched to observationally similar pixels in unprotected ejidos in moist broadleaf forests. (DOCX)

Covariate balance table for unprotected pixels within protected parceled ejidos matched to observationally similar pixels in unprotected parceled ejidos in moist broadleaf forests. (DOCX)

Covariate balance tables for protected ejido pixels matched to protected parceled ejido pixels—Dry broadleaf forest. (DOCX)

Covariate balance tables for unprotected ejido pixels matched to unprotected private property pixels—Dry broadleaf forest. (DOCX)

Covariate balance tables for unprotected ejido pixels matched to unprotected private property pixels—Moist broadleaf forest. (DOCX)

Covariate balance tables for unprotected parcelized ejido pixels matched to unprotected private property pixels—Dry broadleaf forest. (DOCX)

Covariate balance tables for unprotected ejido pixels matched to unprotected parcelized ejido pixels—Moist broadleaf forest. (DOCX)

We define two implementation levels for reduced-impact logging for climate mitigation (RIL-C) practices for felling, skidding, and hauling in dipterocarp forest concessions of East and North Kalimantan. Each implementation level reduces logging emissions by a consistent proportion below the business-as-usual emissions baseline, which varies with ha...

Selective logging causes at least half of the emissions from tropical forest degradation. Reduced-impact logging for climate (RIL-C) is proposed as a way to maintain timber production while minimizing forest damage. Here we synthesize data from 61 coordinated field-based surveys of logging impacts in seven countries across the tropics. We estimate...

We respond to concerns raised by Baldocchi and Penuelas who question the potential for ecosystems to provide carbon sinks and storage, and conclude that we should focus on decarbonizing our energy systems. While we agree with many of their concerns, we arrive at a different conclusion: we need strong action to advance both clean energy solutions an...

Tropical forests are globally significant for both biodiversity conservation and the production of economically valuable wood products. To deliver both simultaneously, two contrasting approaches have been suggested; one partitions forests (sparing), the other integrates both objectives in the same location (sharing). To date, the ‘sparing or sharin...

Limiting climate warming to <2°C requires increased mitigation efforts, including land stewardship, whose potential in the United States is poorly understood. We quantified the potential of natural climate solutions (NCS)—21 conservation, restoration, and improved land management interventions on natural and agricultural lands—to increase carbon st...

Significance Most nations recently agreed to hold global average temperature rise to well below 2 °C. We examine how much climate mitigation nature can contribute to this goal with a comprehensive analysis of “natural climate solutions” (NCS): 20 conservation, restoration, and/or improved land management actions that increase carbon storage and/or...

How should we meet the demand for wood while minimizing climate and biodiversity impacts? We address this question for tropical forest landscapes designated for timber production. We model carbon and biodiversity outcomes for four archetypal timber production systems that all deliver the same volume of timber but vary in their spatial extent and ha...

Reduced-impact logging (RIL) is a promising management strategy for biodiversity conservation and carbon sequestration, but incentive mechanisms are hindered by inadequate monitoring methods. We mapped 937ha of logging infrastructure in a selectively harvested tropical forest to inform a scalable approach to measuring the impacts of discrete manage...

The increasing demand for agricultural commodities is a major cause of tropical deforestation. However, pressure is increasing for greater sustainability of commodity value chains. This includes the demand to establish new crop plantations and pasture areas on already deforested land so that new forest clearing for agriculture is minimized. Where t...

Background: Forest conservation efforts are increasingly being implemented at the scale of sub-national jurisdictions in order to mitigate global climate change and provide other ecosystem services. We see an urgent need for robust estimates of historic forest carbon emissions at this scale, as the basis for credible measures of climate and other...

Complete carbon flux equation. (DOCX)

Legal logging activity methods, and illegal logging emissions methods and results. (DOCX)

Biomass benchmark map methods, results, and comparison with alternatives. (DOCX)

R-code for Monte Carlo simulation. (DOCX)

Methods and results for accuracy assessment of Hansen forest loss product. (DOCX)

BW Griscom and RC Goodman share their views on reframing the land sharing against sparing debate for tropical forestry landscapes. Latest conservation studies tend to conclude that sparing is the best way to maintain agricultural yields while protecting biodiversity. Support of the intensification sparing approach is adopted as the amount of native...

In their response to our recent article (Putz et al. 2012), Kormos and Zimmerman (K&Z) do not take issue with the result of our meta-analysis of more than 100 published studies that biodiversity and carbon stocks are mostly retained in selectively logged tropical forests.