Environment

Charles Palmer

To stem biodiversity loss, the post-2020 Global Biodiversity Framework proposes a substantial expansion of area-based conservation measures. However, half of the earth's land is under agriculture. The expansion of area-based measures in agricultural landscapes necessitates the sparing, or setting aside, of land from production, potentially generating biodiversity benefits yet at the risk of a reduction in food supply.

Focusing on bird species and cereals, we empirically evaluate biodiversity-food trade-offs in a set-aside scheme implemented in England between 1992-2007. Using the first panel dataset of bird counts and land uses at the landscape scale, we find that higher rates of set-aside increase species abundance and richness by, respectively, 1.2-2.1% and 0.7-0.9%, but have no impact on diversity (Shannon-Wiener index). These effects are discontinuous, subject to thresholds in set-aside areas. A minimum 200ha of set-aside, about 3% of agricultural land, is required for a positive effect on biodiversity. A higher threshold, exceeding 900ha of set-aside, equivalent to around 13% of agricultural land, generates a 15-25% and 30-35% increase in abundance and richness, respectively.

Estimates of short- and long-run effects show that impacts are larger in the long-run, reflecting population and species-area dynamics, and the benefits of a sustained policy. In a second, farm-level panel dataset, set-aside is associated with a 10-17% decline in cereal output, with weak evidence of an attenuating land-sparing effect on yields.

Our results suggest that although biodiversity-food trade-offs are likely in high-yield agricultural landscapes, such as those in England, the risk of a reduction in food supply could be minimised in low-yield landscapes, that is, where there is still scope for intensification.

Active travel (AT) – also called healthy or green travel – is a shift to more physically active and environmentally sustainable modes, namely walking and cycling. This is meant to address climate and public health crises by reducing carbon-emitting journeys and providing an urban environment that facilitates physical movement and exposure to nature. The UK has set a target of half of all urban journeys being cycled or walked by 2030. Incorporating existing parks and green spaces into travel routes is fundamental to AT objectives. As such, parks are reconceptualised from stand-alone destinations to interconnected, essential components of wider urban journeys. This necessitates a strategic spatial and administrative planning approach that typically involves a range of landowners and land managers.Yet, a deeply embedded sociocultural approach to park design and governance that prioritises enclosing parks, such as with railings, fencing and walls, may impede AT’s sustainability goals. 

This research explores the impact that railings and similar structures built to enclose parks and green spaces have on integrating these spaces into AT routes in three UK cities: Liverpool, Birmingham and London. Each city has been progressive in adopting AT strategies and each has a legacy of traditional parks they expect to incorporate into enhanced walking-and-cycling infrastructure. As such, the research examines whether the cultural approach to providing parks affects urban sustainability objectives, as delineated in recent Active Travel strategies adopted by UK local governments. 

Eugenie Dugoua

Reducing carbon emissions requires developing clean technologies, and thus, innovation plays a central role in dealing with climate change. Models of directed technical change show how tax and R&D subsidies can rapidly redirect scientists' research activities towards the clean sector.

This project investigates whether inventors can be induced to work on cleaner technologies and the kinds of adjustment costs they face. To do so, we use patent data to describe inventors' specialization across fields and over time, and we leverage quasi-random variation in energy prices to explore whether prices can induce inventors to shift their activities.

We find that inventors patenting both clean and dirty technologies are rare and only a small sub-sample of dirty inventors are susceptible to inducement. These results imply that inventors may not easily adjust to climate policy and stress the need for early-stage supply-side innovation policies to increase the pool of new clean inventors.

Giles Atkinson

Accounting for ecosystems is increasingly central to natural capital accounting (NCA). What is missing from this, however, is an answer to questions about how natural capital is distributed. Addressing this silence, in NCA, on distributional issues is crucial. If natural capital is a critically valuable component of national wealth, then knowing how that value is distributed is surely relevant as well. Broadly speaking there are two ways of asking this distributional question.

Firstly, who consumes ecosystem services and secondly who owns or manages the underlying asset(s) that give rise to ecosystem services. Within NCA, for example, extending supply-use tables is one means of building answers to such questions. In this way, initial work by Atkinson and Ovando (2022) has examined the significance of ownership of land on which ecosystem assets are located.

Ongoing work is extending this picture to England, a policy context where natural capital payments are being seriously considered with implications for wealth distribution. Such distributional issues deserve to be more at the heart of NCA, especially as this measurement tool becomes ever more present and integrated within the balance sheets of nations.

Kasia Paprocki

What are people talking about when they talk about climate change? How do claims about climate change reshape socio-ecological worlds?

In this project we examine in comparative perspective what climate change is and does—both as a set of uneven material effects that are physically transforming the world, and as a productive idea that motivates interventions of various kinds.

This ‘social life of climate change’, we will demonstrate, consists not only of the physical alterations that result from greenhouse gas emissions but also the diverse socio-ecological dynamics resulting from efforts to define, adapt to and mitigate them. These dynamics are always mediated by existing and historical power relations. In this sense, climate change does not transcend the social and material features of the world, rather it is produced and experienced through them.

Michael Mason

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Sefi Roth

Econometric analysis of the global impact of temperature fluctuations on aggregate economic performance (GDP) implies a relationship in which higher temperatures are costly to warm countries but potentially beneficial to cooler ones. However, aggregate temperature-GDP relationships reflect the net effect of temperature on productivity in the constituent sectors of the economy and across different spatial scales, potentially masking the important heterogeneous sectoral and local level effects that could inform efficient adaptation policies.

Focusing on Europe, we use administrative district level data on the growth rate of Gross-Value Added (GVA) to estimate the impact of temperature fluctuations on total GVA growth at the district level, GVA growth by sector and by areas of similar mean temperature. Unlike previous studies with a global focus, for Europe we find persistently negative effects of warmer-than-average years on total GVA in relatively cold districts (annual mean temperatures < 13 degrees C). At an annual mean temperature of 11 degrees Celsius, one additional degree lowers the growth rate of GVA in the same year by -0.37 percentage points (SE = 0.2). The cumulative effect over 6 years is -1.8 percentage points (SE = 0.5). Disaggregating by economic sector we find that the negative aggregate impact in cold districts stems from costs to agriculture, manufacturing, and mining and utilities. In relatively warm districts, the negative effect of higher annual mean temperatures on GVA in trade and other services but it is offset by positive effects in other sectors.

Finally, we find that productivity impacts are also subject to spatial spillovers from neighbouring districts, reflecting how temperature effects dissipate through the regional economy. Overall, our results turn the narrative that warmer than average temperature will be economically advantageous to colder regions on its head and show that positive temperature shocks are instead costly to cold regions of Europe.

Stephen Jarvis

Utility companies recover their capital costs through regulator-approved rates of return on debt and equity. The US costs of risky and risk-free capital have fallen dramatically in the past 40 years, but these utility rates of return have not. We estimate the gap between what utilities are paid now, and what they would have been paid if their rate of return had followed capital markets, using a comprehensive database of utility rate cases dating back to the 1980s.

We estimate that the current average return on equity is 0.5--4 percentage points higher than historical relationships would suggest, and consumers pay an average of $2-14 billion per year more than they would otherwise. We then revisit the effect posited by Averch and Johnson (1962), estimating the consequences of this incentive to own more capital: a 1 percentage point increase in the return on equity increases new capital investment by about 5% in our preferred estimate.