Step back from the forest and step up to the Bonn Challenge: how a broad ecological perspective can promote successful landscape restoration

We currently face both an extinction and a biome crisis embedded in a changing climate. Many biodiverse ecosystems are being lost at far higher rates than they are being protected or ecologically restored. At the same time, natural climate solutions offer opportunities to restore biodiversity while mitigating climate change. The Bonn Challenge is a U.N. programme to restore biodiversity and mitigate climate change through restoration of the world's degraded landscapes. It provides an unprecedented chance for ecological restoration to become a linchpin tool for addressing many environmental issues. Unfortunately, the Forest and Landscape Restoration programme that underpins the Bonn Challenge, as its name suggests, remains focused on trees and forests, despite rising evidence that many non‐forest ecosystems also offer strong restoration potential for biodiversity and climate mitigation. We see a need for restoration to step back to be more inclusive of different ecosystem types and to step up to provide integrated scientific knowledge to inform large‐scale restoration. Stepping back and up will require assessments of where to restore what species, with recognition that in many landscapes multiple habitat types should be restored. In the process, trade‐offs in the delivery of different ecosystem services (e.g. carbon, biodiversity, water, albedo, livestock forage) should be clearly addressed. We recommend that biodiversity safeguards be included in policy and implemented in practice, to avoid undermining the biophysical relationships that provide ecosystem resilience to climate change. For ecological restoration to contribute to international policy goals will require integrated large‐scale science that works across biome boundaries.     

Natural regeneration in the context of large‐scale forest and landscape restoration in the tropics

Large‐scale and long‐term restoration efforts are urgently needed to reverse historical global trends of deforestation and forest degradation in the tropics. Restoration of forests within landscapes offers multiple social, economic, and environmental benefits that enhance lives of local people, mitigate effects of climate change, increase food security, and safeguard soil and water resources. Despite rapidly growing knowledge regarding the extent and feasibility of natural regeneration and the environmental and economic benefits of naturally regenerating forests in the tropics, tree planting remains the major focus of restoration programs. Natural regeneration is often ignored as a viable land‐use option. Here, we assemble a set of 16 original papers that provide an overview of the ecological, economic, and social dimensions of forest and landscape restoration (FLR), a relatively new approach to forest restoration that aims to regain ecological integrity and enhance human well‐being in deforested or degraded forest landscapes. The papers describe how spontaneous (passive) and assisted natural regeneration can contribute to achieving multiple social and ecological benefits. Forest and landscape restoration is centered on the people who live and work in the landscape and whose livelihoods will benefit and diversify through restoration activities inside and outside of farms. Given the scale of degraded forestland and the need to mitigate climate change and meet human development needs in the tropics, harnessing the potential of natural regeneration will play an essential role in achieving the ambitious goals that motivate global restoration initiatives.     

Integrating spread dynamics and economics of timber production to manage Chinese tallow invasions in southern U.S. forestlands

Economic costs associated with the invasion of nonnative species are of global concern. We estimated expected costs of Chinese tallow (Triadica sebifera (L.) Small) invasions related to timber production in southern U.S. forestlands under different management strategies. Expected costs were confined to the value of timber production losses plus costs for search and control. We simulated management strategies including (1) no control (NC), and control beginning as soon as the percentage of invaded forest land exceeded (2) 60 (Low Control), (3) 25 (Medium Control), or (4) 0 (High Control) using a spatially-explicit, stochastic, bioeconomic model. With NC, simulated invasions spread northward and westward into Arkansas and along the Gulf of Mexico to occupy ≈1.2 million hectares within 20 years, with associated expected total costs increasing exponentially to ≈$300 million. With LC, MC, and HC, invaded areas reached ≈275, 34, and 2 thousand hectares after 20 years, respectively, with associated expected costs reaching ≈$400, $230, and $200 million. Complete eradication would not be cost-effective; the minimum expected total cost was achieved when control began as soon as the percentage of invaded land exceeded 5%. These results suggest the importance of early detection and control of Chinese tallow, and emphasize the importance of integrating spread dynamics and economics to manage invasive species.     

Cost Benefit Analysis of Two Policy Options for Cannabis: Status Quo and Legalisation

Aims

To date there has been limited analysis of the economic costs and benefits associated with cannabis legalisation. This study redresses this gap. A cost benefit analysis of two cannabis policy options the status quo (where cannabis use is illegal) and a legalised–regulated option was conducted.

Method

A cost benefit analysis was used to value the costs and benefits of the two policies in monetary terms. Costs and benefits of each policy option were classified into five categories (direct intervention costs, costs or cost savings to other agencies, benefits or lost benefits to the individual or the family, other impacts on third parties, and adverse or spill over events). The results are expressed as a net social benefit (NSB).

Findings

The mean NSB per annum from Monte Carlo simulations (with the 5 and 95 percentiles) for the status quo was $294.6 million AUD ($201.1 to $392.7 million) not substantially different from the $234.2 million AUD ($136.4 to $331.1 million) for the legalised–regulated model which excludes government revenue as a benefit. When government revenue is included, the NSB for legalised–regulated is higher than for status quo. Sensitivity analyses demonstrate the significant impact of educational attainment and wellbeing as drivers for the NSB result.

Conclusion

Examining the percentiles around the two policy options, there appears to be no difference between the NSB for these two policy options. Economic analyses are essential for good public policy, providing information about the extent to which one policy is substantially economically favourable over another. In cannabis policy, for these two options this does not appear to be the case.     

The costs and benefits of screening for congenital hypothyroidism in Wisconsin

Abstract

A comprehensive benefit‐cost analysis of the screening program to detect newborns with congenital hypothyroidism in Wisconsin is presented. Congenital hypothyroidism, if left undetected and untreated at an early age, can have serious irreversible effects on the growth and development of the brain. The monetary costs of the detection and treatment program for congenital hypothyroidism were compared with the projected benefits (avoided costs) that result from the prevention of the mental retardation associated with the disorder. Future costs and benefits were determined using a 4 per cent, 7 per cent, and 10 per cent rate of discount. Net benefits (benefits minus costs) for detecting and treating one individual with congenital hypothyroidism were approximately $98,200 ($141,700 ‐ $43,500) using the 7 per cent rate of discount. Net benefits for detecting the 13 individuals with congenital hypothyroidism in 1981–1982 totaled $1,277,000.     

The income and production effects of biotech crops globally 1996-2010

A critical feature in evaluating the global value of crop biotechnology in agriculture must include an assessment of its economic impact at the farm level. This paper follows earlier studies which examined economic impacts on yields, key costs of production, direct farm income, indirect (non-pecuniary) farm level income effects and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialization of biotech crops is continuing to proceed rapidly, with significant changes in the overall level of adoption and impact taking place in 2010. This updated analysis shows that there have been substantial net economic benefits at the farm level amounting to $14 billion in 2010 and $78.4 billion for the 15-year period (in nominal terms). The non-pecuniary benefits associated with the use of the technology have also had a positive impact on adoption (in the US accounting for the equivalent of 22% of the total US direct farm income benefit). Biotech crops are, moreover, making important contributions to increasing global production levels of the four main crops. They have, for example, now added 97.5 million tons and 159 million tons respectively, to the global production of soybeans and corn since the introduction of the technology in the mid-1990s.     

Emerging Threats and Opportunities for Large‐Scale Ecological Restoration in the Atlantic Forest of Brazil

Over the past 150 years, Brazil has played a pioneering role in developing environmental policies and pursuing forest conservation and ecological restoration of degraded ecosystems. In particular, the Brazilian Forest Act, first drafted in 1934, has been fundamental in reducing deforestation and engaging private land owners in forest restoration initiatives. At the time of writing (December 2010), however, a proposal for major revision of the Brazilian Forest Act is under intense debate in the National Assembly, and we are deeply concerned about the outcome. On the basis of the analysis of detailed vegetation and hydrographic maps, we estimate that the proposed changes may reduce the total amount of potential areas for restoration in the Atlantic Forest by approximately 6 million hectares. As a radically different policy model, we present the Atlantic Forest Restoration Pact (AFRP), which is a group of more than 160 members that represents one of the most important and ambitious ecological restoration programs in the world. The AFRP aims to restore 15 million hectares of degraded lands in the Brazilian Atlantic Forest biome by 2050 and increase the current forest cover of the biome from 17% to at least 30%. We argue that not only should Brazilian lawmakers refrain from revising the existing Forest Law, but also greatly step up investments in the science, business, and practice of ecological restoration throughout the country, including the Atlantic Forest. The AFRP provides a template that could be adapted to other forest biomes in Brazil and to other megadiversity countries around the world.     

The Cost and Cost-Effectiveness of Scaling up Screening and Treatment of Syphilis in Pregnancy: A Model

Background

Syphilis in pregnancy imposes a significant global health and economic burden. More than half of cases result in serious adverse events, including infant mortality and infection. The annual global burden from mother-to-child transmission (MTCT) of syphilis is estimated at 3.6 million disability-adjusted life years (DALYs) and $309 million in medical costs. Syphilis screening and treatment is simple, effective, and affordable, yet, worldwide, most pregnant women do not receive these services. We assessed cost-effectiveness of scaling-up syphilis screening and treatment in existing antenatal care (ANC) programs in various programmatic, epidemiologic, and economic contexts.

Methods and Findings

We modeled the cost, health impact, and cost-effectiveness of expanded syphilis screening and treatment in ANC, compared to current services, for 1,000,000 pregnancies per year over four years. We defined eight generic country scenarios by systematically varying three factors: current maternal syphilis testing and treatment coverage, syphilis prevalence in pregnant women, and the cost of healthcare. We calculated program and net costs, DALYs averted, and net costs per DALY averted over four years in each scenario. Program costs are estimated at $4,142,287 – $8,235,796 per million pregnant women (2010 USD). Net costs, adjusted for averted medical care and current services, range from net savings of $12,261,250 to net costs of $1,736,807. The program averts an estimated 5,754 – 93,484 DALYs, yielding net savings in four scenarios, and a cost per DALY averted of $24 – $111 in the four scenarios with net costs. Results were robust in sensitivity analyses.

Conclusions

Eliminating MTCT of syphilis through expanded screening and treatment in ANC is likely to be highly cost-effective by WHO-defined thresholds in a wide range of settings. Countries with high prevalence, low current service coverage, and high healthcare cost would benefit most. Future analyses can be tailored to countries using local epidemiologic and programmatic data.     

Benefit Cost Analysis of Three Skin Cancer Public Education Mass-Media Campaigns Implemented in New South Wales,Australia

Public education mass media campaigns are an important intervention for influencing behaviour modifications. However, evidence on the effectiveness of such campaigns to encourage the population to reduce sun exposure is limited. This study investigates the benefits and costs of three skin cancer campaigns implemented in New South Wales from 2006–2013. This analysis uses Australian dollars (AUD) and 2010–11 as the currency and base year, respectively. Historical data on skin cancer were used to project skin cancer rates for the period 2006–2020. The expected number of skin cancer cases is derived by combining skin cancer rates, sunburn rates and relative risk of skin cancers due to sun exposure. Counterfactual estimates are based on sunburn exposure in the absence of the campaigns. Monetary values are attached to direct (treatment) and indirect (productivity) costs saved due to fewer skin cancer cases. Monetary benefits are compared with the cost of implementing the campaigns and are presented in the form of a benefit-cost ratio. Relative to the counterfactual (i.e., no campaigns) there are an estimated 13,174 fewer skin cancers and 112 averted deaths over the period 2006–2013. The net present value of these benefits is $60.17 million and the campaign cost is $15.63 million. The benefit cost ratio is 3.85, suggesting that for every $1 invested a return of $3.85 is achieved. Skin cancer public education mass media campaigns are a good investment given the likely extent to which they reduce the morbidity, mortality and economic burden of skin cancer.     

Ecosystem services altered by human changes in the nitrogen cycle: a new perspective for US decision making

Human alteration of the nitrogen (N) cycle has produced benefits for health and well-being, but excess N has altered many ecosystems and degraded air and water quality. US regulations mandate protection of the environment in terms that directly connect to ecosystem services. Here, we review the science quantifying effects of N on key ecosystem services, and compare the costs of N-related impacts or mitigation using the metric of cost per unit of N. Damage costs to the provision of clean air, reflected by impaired human respiratory health, are well characterized and fairly high (e.g. costs of ozone and particulate damages of $28 per kg NO(x)-N). Damage to services associated with productivity, biodiversity, recreation and clean water are less certain and although generally lower, these costs are quite variable (<$2.2-56 per kg N). In the current Chesapeake Bay restoration effort, for example, the collection of available damage costs clearly exceeds the projected abatement costs to reduce N loads to the Bay ($8-15 per kg N). Explicit consideration and accounting of effects on multiple ecosystem services provides decision-makers an integrated view of N sources, damages and abatement costs to address the significant challenges associated with reducing N pollution.     

On the teaching of ecological restoration in Brazil: an analysis of postgraduate courses

Several ambitious restoration targets have been set for recovering degraded ecosystems in Brazil (21 million hectares with a legal deficit of native vegetation). The development of scientific knowledge and skilled professionals is necessary to meet this demand and is fundamental for achieving success in medium‐ and long‐term restoration. In this study, we describe the availability and profile of postgraduate courses on ecological restoration in Brazil. We surveyed 272 postgraduate programs, comprising six specific areas of concentration (forestry, soil sciences, botany, environmental engineering, ecology, and environmental science). We analyzed all selected courses in terms of location, approach (economic, social, and legal), and restoration techniques. Only 27% of the postgraduate programs analyzed offer ecological restoration courses, and 49% of these are offered in the southeast region of the country. Regions covered by nonforest ecosystems, such as Pampas, Caatinga, and Pantanal, were poorly represented. Legal aspects were considered in 51% of the courses, whereas social and economic approaches were only considered in 2.7 and 11% of the courses, respectively. Seedling planting (85%) and nucleation (68%) were the most frequently cited techniques of active restoration, and passive restoration was mentioned in 63% of the courses. Our findings highlight the need for increasing postgraduate courses in areas with nonforest ecosystems, especially due to a lack of knowledge about restoration of these areas. The incorporation of economic and social approaches is highly recommended, considering the importance of these attributes in achieving success in large‐scale restoration initiatives.     

Identifying restoration hotspots that deliver multiple ecological benefits

Ecological restoration principally seeks to restore lost or degraded ecosystems. Restoration can, however, also deliver a suite of wider ecological, social, and economic benefits. To optimize performance it is, therefore, important to plan the design and placement of restoration initiatives with a view to maximizing joint effects on ecosystems, animal populations, ecological functions, and ecosystem services. We measured the effects of multiple (13) restored oyster reefs on a suite of restoration benefits (oyster settlement and growth, fish diversity and abundance, the ecological functions of scavenging and predation) in the Noosa River estuary, Australia, and used distribution models to identify potential restoration sites with the greatest overall benefits. Oysters recruited to reefs, and reefs enhanced the diversity and abundance of fishes and had higher rates of ecological functions than control sites. However, the growth of oyster reefs was most correlated with the proximity of restoration sites to urbanized shorelines and the estuary mouth, and the area of mangroves around the site. By contrast, fish diversity and abundance, and the rates of ecological functions, were typically negatively correlated with the proximity of reefs to both mangroves and seagrasses. This complex spatial mosaic resulted in distinct areas predicted to achieve all restoration benefits that were significantly smaller than the total area that could be restored. Applying a systematic and defensible method to identify potential restoration sites that maximize multiple benefits while lowering costs is a sensible social, economic, and ecological strategy.     

Benefits and costs of ecological restoration: Rapid assessment of changing ecosystem service values at a U.K. wetland

Restoration of degraded land is recognized by the international community as an important way of enhancing both biodiversity and ecosystem services, but more information is needed about its costs and benefits. In Cambridgeshire, U.K., a long-term initiative to convert drained, intensively farmed arable land to a wetland habitat mosaic is driven by a desire both to prevent biodiversity loss from the nationally important Wicken Fen National Nature Reserve (Wicken Fen NNR) and to increase the provision of ecosystem services. We evaluated the changes in ecosystem service delivery resulting from this land conversion, using a new Toolkit for Ecosystem Service Site-based Assessment (TESSA) to estimate biophysical and monetary values of ecosystem services provided by the restored wetland mosaic compared with the former arable land. Overall results suggest that restoration is associated with a net gain to society as a whole of $199 ha⁻¹y⁻¹, for a one-off investment in restoration of $2320 ha⁻¹. Restoration has led to an estimated loss of arable production of $2040 ha⁻¹y⁻¹, but estimated gains of $671 ha⁻¹y⁻¹ in nature-based recreation, $120 ha⁻¹y⁻¹ from grazing, $48 ha⁻¹y⁻¹ from flood protection, and a reduction in greenhouse gas (GHG) emissions worth an estimated $72 ha⁻¹y⁻¹. Management costs have also declined by an estimated $1325 ha⁻¹y⁻¹. Despite uncertainties associated with all measured values and the conservative assumptions used, we conclude that there was a substantial gain to society as a whole from this land-use conversion. The beneficiaries also changed from local arable farmers under arable production to graziers, countryside users from towns and villages, and the global community, under restoration. We emphasize that the values reported here are not necessarily transferable to other sites.     

A Quantitative Assessment of the Conservation Benefits of the Wetlands Reserve Program to Amphibians

The Mississippi Alluvial Valley (MAV) originally consisted of nearly contiguous bottomland hardwood (BLH) forest encompassing approximately 10 million hectares. Currently, only 20–25% of the historical BLH forests remain in small patches fragmented by agricultural lands. The Wetlands Reserve Program (WRP) was established to restore and protect the functions and values of wetlands in agricultural landscapes. To assess the potential benefit of WRP restoration to amphibians, we surveyed 30 randomly selected WRP sites and 20 nearby agricultural sites in the Mississippi Delta. We made repeat visits to each site from May to August 2008 and performed both visual encounter and vocalization surveys. We analyzed the encounter history data for 11 anuran species using a Bayesian hierarchical occupancy model that estimated detection probability and probability of occurrence simultaneously for each species. Nine of the 11 species had higher probabilities of occurrence at WRP sites compared to agriculture. Derived estimates of species richness were also higher for WRP sites. Five anuran species were significantly more likely to occur in WRP than in agriculture, four of which were among the most aquatic species. It appears that the restoration of a more permanent hydrology at the WRP sites may be the primary reason for this result. Although amphibians represent only one group of wildlife species, they are useful for evaluating restoration benefits for wildlife because of their intermediate trophic position. The methods used in this study to evaluate the benefit of restoration could be used in other locations and with other groups of indicator species.     

Economics of microsurgical cases and routine cases in a medical center

This report describes the economic impact of microsurgical cases and routine plastic surgery cases in our medical center. The study is based on a financial analysis of the practices of two surgeons. Financial data of patient encounters (admission to the hospital or a surgical unit) identified with each surgeon were categorized into microsurgical and related cases and routine cases (including cosmetic procedures and general hand cases). Revenues, costs, and profits were tabulated. Data were analyzed for 2 fiscal years (1994-95 and 1995-96). Analysis of the first fiscal year showed that microsurgery encounters (n = 188) generated $4.4 million in revenue with a profit margin after direct costs of $2.5 million (57 percent) and a net profit, after indirect costs, of $1 million (23 percent). Routine encounters (n = 262) generated $1.7 million with a net loss of -$145,000 after direct and indirect costs. In the second fiscal year, microsurgery encounters (n = 230) had income of $4.7 million, a profit over direct costs of $2.5 million (53 percent), and a net profit after indirect costs of $0.9 million (19 percent). Routine cases (n = 202) in the same period earned $1.3 million with a net loss of -$107,000. This analysis formulates a comprehensive definition of microsurgical practice and shows that cases within this definition generated dramatically higher hospital incomes and profits compared with routine plastic surgical practice. In the circumstances of our medical center, development of this subspecialty is fiscally justifiable.     

Effects of Flow Restoration and Exotic Species Removal on Recovery of Native Fish: Lessons from a Dam Decommissioning

Flow diversion and invasive species are two major threats to freshwater ecosystems, threats that restoration efforts attempt to redress. Yet, few restoration projects monitor whether removal of these threats improve target characteristics of the ecosystem. Fewer still have an appropriate experimental design from which causal inferences can be drawn as to the relative merits of removing exotic fish, restoring flow, or both. We used a dam decommissioning in Fossil Creek, Arizona, to compare responses of native fish to exotic fish removal and flow restoration, using a before‐after‐control‐impact design with three impact treatments: flow restoration alone where exotics had not been present, flow restoration and exotic fish removal, and flow restoration where exotics remain and a control reach that was unaffected by restoration actions. We show that removal of exotic fish dramatically increased native fish abundance. Flow restoration also increased native fish abundance, but the effect was smaller than that from removing exotics. Flow restoration had no effect where exotic fish remained, although it may have had other benefits to the ecosystem. The cost to restore flow ($12 million) was considerably higher than that to eradicate exotics ($1.1 million). The long‐term influence of flow restoration could increase, as travertine dams grow and re‐shape the creek increasing habitat for native fish. But in the 2‐year period considered here, the return on investment for extirpating exotics far exceeded that from flow restoration. Projects aimed to restore native fish by restoring flow should also consider the additional investment required to eradicate exotic fish.     

Potential Cost-Effectiveness of a New Infant Tuberculosis Vaccine in South Africa - Implications for Clinical Trials: A Decision Analysis

Novel tuberculosis vaccines are in varying stages of pre-clinical and clinical development. This study seeks to estimate the potential cost-effectiveness of a BCG booster vaccine, while accounting for costs of large-scale clinical trials, using the MVA85A vaccine as a case study for estimating potential costs. We conducted a decision analysis from the societal perspective, using a 10-year time frame and a 3% discount rate. We predicted active tuberculosis cases and tuberculosis-related costs for a hypothetical cohort of 960,763 South African newborns (total born in 2009). We compared neonatal vaccination with bacille Calmette-Guérin alone to vaccination with bacille Calmette-Guérin plus a booster vaccine at 4 months. We considered booster efficacy estimates ranging from 40% to 70%, relative to bacille Calmette-Guérin alone. We accounted for the costs of Phase III clinical trials. The booster vaccine was assumed to prevent progression to active tuberculosis after childhood infection, with protection decreasing linearly over 10 years. Trial costs were prorated to South Africa''s global share of bacille Calmette-Guérin vaccination. Vaccination with bacille Calmette-Guérin alone resulted in estimated tuberculosis-related costs of $89.91 million 2012 USD, and 13,610 tuberculosis cases in the birth cohort, over the 10 years. Addition of the booster resulted in estimated cost savings of $7.69–$16.68 million USD, and 2,800–4,160 cases averted, for assumed efficacy values ranging from 40%–70%. A booster tuberculosis vaccine in infancy may result in net societal cost savings as well as fewer active tuberculosis cases, even if efficacy is relatively modest and large scale Phase III studies are required.     

The power of data synthesis to shape the future of the restoration community and capacity

Restoration efforts will be taking place over the next decade(s) in the largest scope and capacity ever seen. Immense commitments, goals, and budgets are set, with impactful wide‐reaching potential benefits for people and the environment. These are ambitious aims for a relatively new branch of science and practice. It is time for restoration action to scale up, the legacy of which could impact over 350 million hectares targeted for the U.N. Decade on Ecosystem Restoration. However, restoration still proceeds on a case‐by‐case, trial by error basis and restoration outcomes can be variable even under similar conditions. The ability to put each case into context—what about it worked, what did not, and why—is something that the synthesis of data across studies can facilitate. The link between data synthesis and predictive capacity is strong. There are examples of extremely ambitious and successful efforts to compile data in structured, standardized databases which have led to valuable insights across regional and global scales in other branches of science. There is opportunity and challenge in compiling, standardizing, and synthesizing restoration monitoring data to inform the future of restoration practice and science. Through global collation of restoration data, knowledge gaps can be addressed and data synthesized to advance toward a more predictive science to inform more consistent success. The interdisciplinary potential of restoration ecology sits just over the horizon of this decade. Through truly collaborative synthesis across foci within the restoration community, we have the opportunity to rapidly reach that potential and achieve extraordinary outcomes together.     

Benefits and costs of improved cookstoves: assessing the implications of variability in health, forest and climate impacts

Current attention to improved cook stoves (ICS) focuses on the "triple benefits" they provide, in improved health and time savings for households, in preservation of forests and associated ecosystem services, and in reducing emissions that contribute to global climate change. Despite the purported economic benefits of such technologies, however, progress in achieving large-scale adoption and use has been remarkably slow. This paper uses Monte Carlo simulation analysis to evaluate the claim that households will always reap positive and large benefits from the use of such technologies. Our analysis allows for better understanding of the variability in economic costs and benefits of ICS use in developing countries, which depend on unknown combinations of numerous uncertain parameters. The model results suggest that the private net benefits of ICS will sometimes be negative, and in many instances highly so. Moreover, carbon financing and social subsidies may help enhance incentives to adopt, but will not always be appropriate. The costs and benefits of these technologies are most affected by their relative fuel costs, time and fuel use efficiencies, the incidence and cost-of-illness of acute respiratory illness, and the cost of household cooking time. Combining these results with the fact that households often find these technologies to be inconvenient or culturally inappropriate leads us to understand why uptake has been disappointing. Given the current attention to the scale up of ICS, this analysis is timely and important for highlighting some of the challenges for global efforts to promote ICS.     

A lesson unlearned? Underestimating tree cover in drylands biases global restoration maps

Two recent global maps of tree restoration potential have identified vast regions where tree cover could be increased, ranging from 0.9 to 2.3 billion hectares. Both maps, however, emphasized dryland regions, with arid biomes making up 36%–42% of potential restoration area. Dryland biomes have repeatedly been recognized as inappropriate regions for expanding tree cover due to the risks of biodiversity loss, water overconsumption, and fire, so maps that highlight these regions for restoration must sustain careful scrutiny. Here, I show that both recent attempts to map restoration potential in arid regions have been hindered by underlying errors in the global tree cover maps they used. Systematic underestimates of existing sparse tree cover led directly to large overestimates of the potential for tree recovery in drylands. The Atlas of Forest Landscape Restoration Opportunities (Laestadius et al., Unasylva, 2011, 62, 47) overestimated tree restoration potential across a third of arid biomes by between 7% and 20% (55–166 million hectares [Mha]). Similarly, Bastin, Finegold, Garcia, Mollicone, et al. (Science, 2019, 365, 76) overestimated tree restoration potential across all arid biomes by 33%–45% (316–440 Mha). These inaccuracies limit the utility of this research for policy decisions in drylands and overstate the potential for tree planting to address climate change. Given this long‐standing but underappreciated challenge in mapping global tree cover, I propose various ways forward that keep this lesson in mind. To better monitor and restore tree cover, I call for re‐interpretation and correction of existing global maps, and for a new focus on quantifying sparse tree cover in drylands and other systems.