Recent journal articles and chapters

Abstract:
Accounting for the increasing benefits from scarce ecosystems.

As people get richer, and ecosystem services scarcer, policy-relevant estimates of ecosystem value must rise. 

Abstract:
Quickest Detection of Ecological Regimes for Natural Resource Management.

AbstractWe study the stochastic dynamics of natural resources under the threat of ecological regime shifts. We establish a Pareto optimal framework of regime shift detection under uncertainty that minimizes the delay with which economic agents become aware of the shift. We integrate ecosystem surveillance in the formation of optimal resource extraction policies. We fully solve the case of a profit-maximizing monopolist, study its response to regime shift detection and show the generality of our framework by extending our results to other decision makers and functional forms. We apply our framework to the case of the Cantareira water reservoir in São Paulo, Brazil, and study the events that led to its depletion and the consequent water supply crisis. 

Abstract:
A review of planting principles to identify the right place for the right tree for ‘net zero plus’ woodlands: Applying a place-based natural capital framework for sustainable, efficient and equitable (SEE) decisions.

We outline the principles of the natural capital approach to decision making and apply these to the contemporary challenge of very significantly expanding woodlands as contribution to attaining net zero emissions of greenhouse gases. Drawing on the case of the UK, we argue that a single focus upon carbon storage alone is likely to overlook the other ‘net zero plus’ benefits which woodlands can deliver. A review of the literature considers the wide variety of potential benefits which woodlands can provide, together with costs such as foregone alternative land uses. We argue that decision making must consider all of these potential benefits and costs for the right locations to be planted with the right trees. The paper closes by reviewing the decision support systems necessary to incorporate this information into policy and decision making. Read the free Plain Language Summary for this article on the Journal blog. 

Abstract:
Does local Natural Capital Accounting deliver useful policy and management information? a case study of Dartmoor and Exmoor National Parks.

Natural capital accounting provides a systematic framework through which to quantify the benefits of natural assets. National-scale applications have demonstrated the feasibility of developing such accounts and their value as a tool to support environmental policy and management decisions. Building on that success, there have been increasing calls for sub-national organisations (for example, protected area authorities and water companies) to develop their own natural capital accounts. As we document in this paper, recent efforts by local organisations in the UK to produce such accounts have tended to rely on a set of 'standard practice' methods, many borrowed directly from national natural capital accounting exercises. In this paper, we review those methods and apply them in producing natural capital accounts for two UK National Parks. Working with the National Park Authorities, we critically assess the usefulness of those accounts to inform local land management. On account of data gaps and significant sensitivity to methodological assumptions, our research shows that these local accounts are considered of limited practical use for land management decision making at a local scale. Through specific illustrative examples, we show that natural capital accounts for local decision-making can be improved through: the inclusion of fit-for-purpose data and valuation methods, the consideration of uncertainties, and the incorporation of ecological information and spatial aspects. We also highlight the need for the development of both standardised guidelines and readily-available tools to quantify and value ecosystem services. 

Abstract:
Modelling the impact of forest management and CO2-fertilisation on growth and demography in a Sitka spruce plantation.

Afforestation and reforestation to meet 'Net Zero' emissions targets are considered a necessary policy by many countries. Their potential benefits are usually assessed through forest carbon and growth models. The implementation of vegetation demography gives scope to represent forest management and other size-dependent processes within land surface models (LSMs). In this paper, we evaluate the impact of including management within an LSM that represents demography, using both in-situ and reanalysis climate drivers at a mature, upland Sitka spruce plantation in Northumberland, UK. We compare historical simulations with fixed and variable CO2 concentrations, and with and without tree thinning implemented. Simulations are evaluated against the observed vegetation structure and carbon fluxes. Including thinning and the impact of increasing CO2 concentration ('CO2 fertilisation') gave more realistic estimates of stand-structure and physical characteristics. Historical CO2 fertilisation had a noticeable effect on the Gross Primary Productivity seasonal-diurnal cycle and contributed to approximately 7% higher stand biomass by 2018. The net effect of both processes resulted in a decrease of tree density and biomass, but an increase in tree height and leaf area index. 

Abstract:
Perspectives on valuing water quality improvements using stated preference methods.

Improvements to the quality of freshwater rivers and lakes can generate a wide array of benefits, from "use values" such as recreational boating, fishing, and swimming to "nonuse values" such as improved outcomes for aquatic biodiversity. Bringing these nonmarket values into decision-making is crucial to determining appropriate levels of investment in water quality improvements. However, progress in the economic valuation of water quality benefits has lagged similar efforts to value air quality benefits, with implications for water policy. New data sources, modeling techniques, and innovation in stated preference survey methods offer notable improvements to estimates of use and nonuse benefits of improved water quality. Here, we provide a perspective on how recent applications of stated preference techniques to the valuation of the nonmarket benefits of water quality improvements have advanced the field of environmental valuation. This overview is structured around four key questions: i) What is it about water quality that we seek to value? ii) How should we design and implement the surveys which elicit individuals' stated preferences? iii) How do we assess the validity of the findings provided by such studies? and iv) What are the contributions of these valuation exercises to public policy? in answering these questions, we make reference to the contributions provided by the papers in this Symposium. 

Abstract:
Philosophers and economists agree on climate policy paths but for different reasons.

The estimated value to society from climate change mitigation is highly sensitive to the long-term social discount rate. Governmental discounting guidance has almost exclusively been influenced by economists, although it is not clear that they possess any special expertise on intergenerational ethics. Here, by contrast, we report the views of philosophers, who are the most trained in ethical matters. We show that, as a group, these experts offer strong support for a real social discount rate of 2%, a value that is also predominantly backed by economists. We find multidisciplinary support for climate policy paths in line with the United Nations climate targets when views on discounting determinants are applied within a recent update of the DICE integrated assessment model. However, this apparent agreement hides important differences in views on how the ethics of intergenerational welfare can be better incorporated into climate policy evaluation. 

Abstract:
Realising the social value of impermanent carbon credits.

Efforts to avert dangerous climate change by conserving and restoring natural habitats are hampered by concerns over the credibility of methods used to quantify their long-term impacts. Here we develop a flexible framework for estimating the net social benefit of impermanent nature-based interventions that integrates three substantial advances: (1) conceptualizing the permanence of a project’s impact as its additionality over time; (2) risk-averse estimation of the social cost of future reversals of carbon gains; and (3) post-credit monitoring to correct errors in deliberately pessimistic release forecasts. Our framework generates incentives for safeguarding already credited carbon while enabling would-be investors to make like-for-like comparisons of diverse carbon projects. Preliminary analyses suggest nature-derived credits may be competitively priced even after adjusting for impermanence. 

Abstract:
Realizing the social value of impermanent carbon credits.

Efforts to avert dangerous climate change by conserving and restoring natural habitats are hampered by concerns over the credibility of methods used to quantify their long-term impacts. Here we develop a flexible framework for estimating the net social benefit of impermanent nature-based interventions that integrates three substantial advances: (1) conceptualizing the permanence of a project’s impact as its additionality over time; (2) risk-averse estimation of the social cost of future reversals of carbon gains; and (3) post-credit monitoring to correct errors in deliberately pessimistic release forecasts. Our framework generates incentives for safeguarding already credited carbon while enabling would-be investors to make like-for-like comparisons of diverse carbon projects. Preliminary analyses suggest nature-derived credits may be competitively priced even after adjusting for impermanence. 

Abstract:
The Financial and Environmental Consequences of Renewable Energy Exclusion Zones.

AbstractAs countries decarbonise, the competition for land between energy generation, nature conservation and food production will likely increase. To counter this, modelling, and sometimes energy policies, use exclusion zones to restrict energy deployment from land deemed as important to society. This paper applies the spatially-explicit ADVENT-NEV model to Great Britain to determine the cost imposed on the energy system when either environmental or food production exclusion zones are applied. Results show that exclusion zones impose a cost of up to £0.63 billion (B), £19.17 B and £1.33 B for the solar, wind, and bioenergy pathways. These costs give an indication of the value being placed on protecting these areas of land. When multiple exclusions are imposed on bioenergy, the high pathway is infeasible indicating a more flexible approach may be needed to meet net zero ambitions. The model also shows how the value of ecosystem services changes when exclusion zones are applied, highlighting how some exclusions increase non-market costs whereas others decrease them. In several cases exclusion zones are shown to increase social costs, the opposite of their intended use. For these exclusions to be justifiable, the unobserved values missing from the model must be as large as these increases. 

Abstract:
Trends in tropical forest loss and the social value of emission reductions.

Reducing global forest losses is essential to mitigate climate change and its associated social costs. Multiple market and non-market factors can enhance or reduce forest loss. Here, to understand the role of non-market factors (for example, policies, climate anomalies or conflicts), we can compare observed trends to a reference (expected) scenario that excludes non-market factors. We define an expected scenario by simulating land-use decisions solely driven by market prices, productivities and presumably plausible decision-making. The land-use allocation model considers economic profits and uncertainties as incentives for forest conversion. We compare reference forest losses in Brazil, the Democratic Republic of Congo and Indonesia (2000–2019) with observed forest losses and assign differences from non-market factors. Our results suggest that non-market factors temporarily lead to lower-than-expected forest losses summing to 11.1 million hectares, but also to phases with higher-than-expected forest losses of 11.3 million hectares. Phases with lower-than-expected forest losses occurred earlier than those with higher-than-expected forest losses. The damages avoided by delaying emissions that would otherwise have occurred represent a social value of US$61.6 billion (as of the year 2000). This result shows the economic importance of forest conservation efforts in the tropics, even if reduced forest loss might be temporary and reverse over time. 

Abstract:
Carbon emissions reductions from Indonesia’s moratorium on forest concessions are cost-effective yet contribute little to Paris pledges.

Significance
.
. More than a decade after the global adoption of REDD+ as a climate change mitigation strategy, countries have started accessing results-based payments. However, the extent to which payments are actually based on results is unknown, necessitating program evaluations to establish the contribution of REDD+ to the Paris NDCs. We undertake a microeconometric evaluation of one of the most globally significant REDD+ initiatives, Indonesia’s moratorium on forest concessions, in which a payment has been awarded. At the agreed US$5/tCO
. 2
. -eq, the value of our estimated cumulative carbon emissions far exceeds the proposed payment from the donor, Norway. Although cost-effective, the emissions reductions only contribute 3 to 4% of Indonesia’s NDC. This contribution could be increased in new initiatives with better-designed incentives and institutional arrangements.
.  

Abstract:
Combined carbon and health taxes outperform single-purpose information or fiscal measures in designing sustainable food policies.

The food system is a major source of both environmental and health challenges. Yet, the extent to which policy-induced changes in the patterns of food demand address these challenges remains poorly understood. Using a randomised-controlled survey of 5,912 respondents from the United Kingdom (UK), we evaluate the potential impact of carbon and/or health taxes, information and combined tax and information strategies on food purchase patterns and their resulting impact on greenhouse gas emissions and dietary health. Our results show that while information on the carbon and/or health characteristics of food is not irrelevant, it is the imposition of taxes which exerts the most substantial effects on food purchasing decisions. Furthermore, while carbon or health taxes are best at separately targeting emissions and health challenges respectively, a combined carbon and health tax policy maximises benefits both in terms of environmental and health outcomes. We show that such a combined policy could contribute to around one third of the residual emission reductions required to achieve the UK’s 2050 net zero commitments, while discouraging the purchase of unhealthy snacks, sugary drinks and alcohol and increasing the purchase of fruit and vegetables. 

Abstract:
Language and the cultural markers of COVID-19.

Despite its universal nature, the impact of COVID-19 has not been geographically homogeneous. While certain countries and regions have been severely affected, registering record infection rates and excess deaths, others experienced only milder outbreaks. We investigate to what extent human factors, in particular cultural origins reflected in different attitudes and behavioural norms, can explain different degrees of exposure to the virus. Motivated by the linguistic relativity hypothesis, we take language as a proxy for cultural origins and exploit the exogenous variation in the language spoken around the border that divides the French- and German-speaking parts of Switzerland to estimate the impact of culture on exposure to COVID-19. The results obtained using a spatial regression discontinuity design reveal, that within 50- and 25- kilometres bandwidth from the language border, the average COVID-19 exposure levels for individuals in French speaking municipalities was higher. In particular, we find that German speaking municipalities were associated with a reduction of around 40% - 50% in the odds of COVID-19 exposure compared to the French speaking municipalities. 

Abstract:
Toward an improved understanding of causation in the ecological sciences.

Society increasingly demands accurate predictions of complex ecosystem processes under novel conditions to address environmental challenges. However, obtaining the process-level knowledge required to do so does not necessarily align with the burgeoning use in ecology of correlative model selection criteria, such as Akaike information criterion. These criteria select models based on their ability to reproduce outcomes, not on their ability to accurately represent causal effects. Causal understanding does not require matching outcomes, but rather involves identifying model forms and parameter values that accurately describe processes. We contend that researchers can arrive at incorrect conclusions about cause-and-effect relationships by relying on information criteria. We illustrate via a specific example that inference extending beyond prediction into causality can be seriously misled by information-theoretic evidence. Finally, we identify a solution space to bridge the gap between the correlative inference provided by model selection criteria and a process-based understanding of ecological systems. 

Abstract:
National Accounting for the Ocean and Ocean Economy.