Impact case study database

Air pollution has long been a serious public health problem. Over 500,000 preventable deaths occur annually across Europe due to air pollution, making it the continent’s largest environmental health risk [A]. In the UK alone, air pollution causes up to 40,000 deaths each year, costing the economy about £20 billion annually [B].

Pioneering research by ApSimon and de Nazelle is transforming policy in the UK and internationally, paving the way for new, more effective solutions. Specifically, their work has impacted air pollution policy in two main ways:

1. by informing new, more effective, strategies for compliance with legally binding international emission ceilings;

2. by incorporating previously overlooked dimensions, including local factors and individual behaviour.

Strategies for Compliance

The UNECE Convention on Long-range Transboundary Air Pollution is the only legally-binding regional agreement of its kind in the world [C] [2]. ApSimon’s pioneering approach to integrated assessment modelling [1, 2] supported governments in the UK and Europe to implement new strategies for cost effective compliance. These have been crucial in abating pollution levels, which have fallen by about 10% over the last 7 years [1]. The Deputy Director of Defra Air Quality & Industrial Emissions, states that: “to design and evaluate effective policies, we need robust and agile evidence … [ApSimon’s work] plays a highly significant contribution to our underpinning evidence base” [D]. A key contribution was ApSimon’s development of the UK Integrated Assessment Model, UKIAM [3]. The Deputy Director of Defra Air Quality & Industrial Emissions describes it “ as a unique capability for modelling future air pollution scenarios for the UK … [enabling] the assessment of the implications for health and natural ecosystems... ” [D].

ApSimon’s recent work for Defra focusses on reducing annual mean concentrations of fine particulate PM2.5 as part of the Government’s Clean Air Strategy [E]. Her extensive analysis of emissions of SO2, NOx, NH3, VOCs and PM2.5 summarised in the ground-breaking report on reduction of exposure to PM2.5 [E] provided the evidence to justify the UK Government’s ambitious commitment to achieving the WHO guideline of 10 ug.m^-3. Defra confirms ApSimon’s contribution, writing: “the UKIAM model has been vital in enabling Defra to set out its ambitions to reduce exposure to fine particulate PM2.5 … The Imperial College Team and the model have a pivotal role to play in setting these targets and in ensuring that ambition is based on sound science.” [D]. They conclude that: “ It is not overstating the fact that the team has a vital role to play in supporting development of policies … by providing the underpinning evidence to enable targeted reductions in exposure to fine particulate matter.” [D]

As the lead of the UK Focal Centre for Integrated Assessment, ApSimon’s work underpinned development of the Gothenburg protocols to control transboundary air pollution in Europe and the National Emissions Ceilings Directive of the EC. The co-chair of the UNECE Task Force on Integrated Assessment Modelling, states that ApSimon is “playing a leading role in strengthening the network of national integrated assessment modellers, which is aimed exchanging information … within the UNECE on understanding of emissions, measures to reduce them, and ways of evaluating the health benefits.” [F]

Local Factors and Individual Behaviour

A theme in the research at Imperial is that technological transformations alone are insufficient to address air pollution. In particular, as shown in [4] and [5], because national- and continental-scale policies often fail to account for local factors and individual decision-making, real-world exposures may not comply with legislated NO2 concentrations [4, 5]. By integrating urban and local dimensions such as traffic and street-scale urban form, ApSimon’s [4, 5] work showed that local processes can amplify or diminish the effectiveness of air pollution policies.

Her colleague, De Nazelle, has extended this work, investigating the trade-offs in individual decisions, particularly to walk and cycle instead of using polluting forms of transportation, showing they can reduce air pollution levels, improve health through increased physical activity, and reduce noise, traffic injuries and greenhouse gas emissions. De Nazelle influenced the transport appraisal by the UK Department for Transport through her report [7, G] that led Public Health England to conclude based on partly her work that, “ …that addressing air pollution can contribute to broader benefits, in particular through increasing physical activity levels in the population” [B]. The Director for Health Protection for Public Health England, confirms De Nazelle’s contribution: “ We have specifically integrated Dr de Nazelle’s findings – in particular those produced during the current REF period, i.e. since August 2013 - in our reports and guidance material such as: Review of Interventions to Improve Outdoor Air Quality and Public Health; Annual Report of the Chief Medical Officer 2017; NICE guideline Physical Activity: Walking and Cycling; Cycling and Walking for Individual and Population Health Benefits; Spatial Planning for Health [and] have also sought Dr de Nazelle’s expertise directly as an advisor to our work reviewing interventions to improve air quality and public health.” [B] Recently PHE has focused on walking and cycling strategies and that “ Dr de Nazelle’s work has been a key contributor to this agenda, which has led to successful uptake by local and national governments of active travel policies.” [B]

de Nazelle’s approach has resulted in new guidelines and policies internationally. She was Co-I on the EU PASTA project, which contributed to a sea-change in how active mobility is perceived and promoted in policy and public discourse. PASTA outputs were cited in global policy documents [H]. The outputs of her PASTA project led to the creation of WHO’s HEAT air pollution module, used by local policy makers internationally to decide on transport investments [I]. The WHO complied a set of 24 case studies across Europe which demonstrated the impact HEAT has had to promote healthy active travel policies [I]. One such example was Transport for London’s use of HEAT to estimate that health made up two thirds of the benefits of their project which reduced space for cars [I]. Beyond HEAT, De Nazelle’s work has been cited in WHO reports and guidance material including the Global Report on Urban Health (2016), Environmental Risks of Cities in the European Region (2017), Preventing Disease through Healthy Environments (2016), Protecting Health in Europe from Climate Change (2017), Promoting Health, Preventing Disease (2015), Health as the Pulse of the New Urban Agenda (2016) [I]. Cycling networks and active travel infrastructure have been expanded in all PASTA case study cities [I]. The WHO Head of Office reports that, “ *expansion of the cycling network in European cities could achieve up to 25% of cycling mode share, which in turn could save more than 10,000 lives (based on estimates of 167 cities)*” [I]. Confirming de Nazelle’s contribution, they add that “ ambitious strategies and major funding have been announced in the past years to promote cycling in particular, directly and importantly influenced by de Nazelle’s work…’ [I].

Introduced pests and invasive species cause over $1 trillion in annual damage worldwide, are a significant barrier to trade, and are second to habitat loss as a cause of global environmental harm. Mumford, Potter and colleagues have developed a series of standards, quantitative models, decision procedures and understanding of ecology, technology and social attitudes that have been adopted by policymakers, regulators and biosecurity risk managers in UN agencies [A, B], EU regulatory bodies [C, D, E], and national authorities [F, G]. Wide engagement by the researchers with policymakers and regulators, internationally and domestically, has demonstrated the importance of pathway-based risk analysis and provided decision makers with an evidence base from which novel quantitative analytical tools and risk communication strategies could be developed and applied to manage existing and emerging biosecurity threats [G]. Mumford’s research on pest risk assessment has informed working groups on which he served to prepare international guidance on use of genetic and radiation-based technologies for pest control (EFSA [H]; WHO/IAEA **[I]**).

Policy impacts

Both Mumford and Potter have been closely involved in development of UK government biosecurity policy [G]. As Chair of Defra’s Non-native Species Risk Analysis Panel, Mumford has been directly involved in advising government on design and implementation of effective biosecurity measures [E, G]; more widely, the UK Minister stated that the process led by Mumford “strongly influenced the EU’s approach, including its risk methodology, when the EU invasive alien species regulation came into force in 2015” [E]. Potter and Mumford were members of Defra’s Tree Health and Plant Biosecurity Task Force, to advise on how to safeguard the country’s trees, woods and forests from invasive pests and diseases [G]. The Taskforce’s recommendations were implemented in full and included creation of a new Plant Health Risk Register, a methodological innovation based on Mumford’s work and launched in 2014, described as “an extremely effective policy innovation which allows the Plant Health Risk Group within Defra to undertake monthly reviews of threats” [G], together with a series of improvements to risk messaging to encourage behavioural changes in horticultural and forestry sectors.

In international standard setting, Mumford’s quantitative, pathways-based modelling has been used to justify new standards and procedures for biosecurity and has been adopted by implementing agencies (EFSA) [D, C], (Defra) [G] and by international standard setting bodies (IPPC, WTO) [A, B]. Mumford provided technical direction to the evaluation of the European Plant Health regime [J] that led to pathway risk analysis being included as a key platform for biosecurity risk management in the EU Plant Health Regulation (2016), implemented in 2019 [B]. Mumford led the design for a prototype quantitative pathway analysis tool for pathway risk analysis for the European Food Safety Authority [D, C], which oversees all fresh produce imports into the EU, worth over €20bn in 2019. With support from the Standards and Trade Development Facility (WTO), Mumford and colleagues developed a pathway-based production chain management system for South East Asian markets. It was adopted by the Philippines, Vietnam, Malaysia and Thailand, a crucial factor assisting these developing economies to negotiate trade agreements to export food commodities that satisfy international IPPC phytosanitary requirements [K, A].

Specific commercial impact

Improved risk management facilitates horticultural trade, with significant and well documented economic benefits for producers in the global south, such as in India on mango [L, M]. For instance, Mumford’s area-wide bait, trap and area-wide approach to fruit flies in India was used in a government scheme on mango fruit fly control to shift from production of low-price pulp and juice markets to higher value fresh fruit sales for mango on tens of thousands of farms [L]. This area-wide fruit fly control in southern India has increased mango yields three-fold and moved from $0.10/kg pulp sales to $1.00/kg fresh fruit sales. This has increased farm gate values by $700 million/year and “transformed the incomes, and the lives, of many rural families” as the “ total annual value of mango production in India increased in value by US$ 3.5 billion for 2013-2019” [M]. Area-wide fruit management using sterile insects (SIT), in a scheme built on Mumford’s concepts, has “ supported export of around $200 million from Brazil in 2018” [B].

Pest risk analysis has been applied to new agricultural commodity trade pathways under the revised EU Plant Health regulations from 2019 [B, following recommendation in J]. New and changing trade pathways, particularly for €30bn/yr horticultural commodities, are subject to pest risk analysis and resulting pest management measures driven by approaches developed by Mumford, Potter and colleagues [B, G].

Global warming, driven by anthropogenic emissions of greenhouse gases, poses severe risks for natural and human systems. Average global temperatures have already risen to approximately 1.0°C above pre-industrial levels as a result of human activities [A] and a science-policy consensus has emerged, enshrined in the Paris Agreement, which seeks to limit warming to well below 2.0°C, and ideally to 1.5°C.

Before Rogelj’s research, policy-makers faced two significant obstacles:

• It was unclear whether and how the 1.5°C limit might be achieved. While numerous groups publish scenarios, none offered a clear way forward to keep warming below the 1.5°C limit. Moreover, the scenarios were risky, permitting the 1.5°C limit to be exceeded (as long as temperatures returned to 1.5°C by 2100) and unfair, placing the greatest burdens on later generations.

• There was also disagreement and misunderstanding about the size of the world’s remaining carbon budget, the total amount of CO₂ that can still be emitted while keeping global warming below the 1.5°C limit. A robust and up-to-date carbon budget estimate was critical to informing climate policies, and tracking performance, but a wide range of conflicting estimates hindered progress.

Rogelj successfully addressed both challenges, by detailing new societal transformation pathways that could limit warming to 1.5°C without exceeding the target or requiring intergenerational unfairness [1, 2, 3], and by establishing a comprehensive, transparent framework for estimating and tracking the carbon budget [5]. He also developed methods [4] to assess the gap between the global warming outcomes likely to result from national climate pledges and the temperature limits established in the Paris Agreement.

As a result, Rogelj’s ground-breaking work has:

1. Transformed science-policy assessments at the international level

2. Driven ambitious policy decisions at the national level

3. Broadened wider societal awareness and engagement in climate change

International impacts

Rogelj’s research provided a critical evidence base for the Special Report on Global Warming of 1.5°C (SR1.5), a landmark report published in October 2018 by the Intergovernmental Panel on Climate Change (IPCC) [A]. More than 15 of Rogelj’s papers were referenced in the SR1.5. Importantly, all four of the central illustrative pathways used by the report to communicate strategic mitigation choices to policymakers are from studies led or co-authored by Rogelj. Indeed, Chapter 2 of the SR1.5 directly referenced Rogelj’s work [1] when describing these pathways (page 110), as well as applying Rogelj’s framework for estimating remaining carbon budget [5] for the first time (pages 104-8). The SR1.5 concludes, again directly based on Rogelj’s research, [3] that pathways consistent with limiting warming to 1.5°C halve global CO₂ emissions by 2030 compared to 2010 and reach net zero CO₂ around mid-century – insights that have had a fundamental impact on national policy.

Rogelj’s research [1, 3, 4] also directly underpins the Emissions Gap Report (EGR) [B], published annually by the UN Environment Programme (UNEP). The EGR estimates how much warming could be expected should countries’ pledges on greenhouse gas emissions-cutting be implemented, and how temperatures would diverge from the limits set out in the Paris Agreement. The Head of Thematic Scientific Assessments at UNEP, confirms that “the novel methods Joeri Rogelj published to assess the gap between countries’ climate pledges and their global warming outcome have become the [EGR’s] scientific and analytical backbone.” [C]. The EGR and - by extension, Rogelj’s work - is of critical importance in international climate policy circles. Referencing the opening session of Conference of the Parties (COP 25), the 2019 UN Climate Change Conference held in Madrid, they note that “ 3 out of 5 speakers … made direct use of EGR messages in their speech. The same was the case for the UN Secretary General in his separate address…” [C]. The EGR findings were referred to in Decisions 1/CMA.2 and 1/CP.25 of COP25, adopted by all 197 countries of the UNFCCC.

National impacts

Rogelj’s research, and the authoritative science-policy assessments it informs, has also directly influenced significant national policy change. The publication of the IPCC SR1.5 [A] prompted the UK, Scottish and Welsh Governments to ask the UK Committee on Climate Change (CCC) to assess its implications for the UK’s long-term climate target and net zero greenhouse gas date [D]. The resulting Net Zero Report [E], published by CCC in May 2019, cites Rogelj’s research database [3] as evidencing four of the six diagrams in Chapter 2, and for all quantitative tables in both Chapter 2 and 3. Insights from Rogelj’s research activities for the UNEP EGR [B] are also cited in the Net Zero Report’s context setting and analysis. The UK CCC corroborates Rogelj’s contribution: “Research outputs of Dr Rogelj played a critical role in shaping the evidence base for the SR1.5 and subsequently informing the CCC advice to Government ” [F]. The CCC Net Zero Report directly led to the UK’s adoption in June 2019 of an ambitious net zero greenhouse gas emissions target as a legally binding national long-term climate goal. The new law [G] explicitly references both the conclusions of the IPCC SR1.5 [A] and the advice provided by the CCC [E].

Similarly, Rogelj’s research on 1.5°C-consistent pathways, included in the IPCC SR1.5, is cited in the First Annual Report of the High Council on Climate of France [H], leading in June 2019 to France setting a national carbon neutrality target in legislation, and referenced as key scientific evidence in the EU’s draft proposal for a European Climate Law [I].

The 2011 UN Global Hidden Hunger Index is designed to measure and track hunger comprehensively. Of the 20 countries with the highest index scores, 18 were in sub-Saharan Africa [A]. The region is susceptible to inherent agricultural supply chain nutritional deficiencies and to escalating climate variability [1-3].

Working with Biffis and Makuch, researchers Chavez and Conway [4] identified a critical gap which meant that bank lending decisions and insurance policies did not serve the needs of many smallholders in the economically marginal and climate exposed sub-Saharan Africa [B]. Agricultural insurance in emerging economies suffers from poor data quality, limited claims experience, high monitoring costs and low uptake [4, B].

Building upon Conway’s foundational research in integrated agricultural practice for resilient food systems and supply chains for sub Saharan Africa [1,2], Chavez extended his PhD research and with Makuch, secured the WINnERS Project [C]. This project implemented a parametric insurance mechanism, integrating agricultural science and economics with weather-related risk insurance, which together with the loan and institutional arrangements make up the basis for this Impact Case Study [D]. The structures that provided the pathway for impact are represented in the following WINnERS Project diagram:

In sub-Saharan Africa, banks and insurers, are powerful players in the food system. The integration of satellite datasets, models, financial schemes and stakeholder engagement enabled an evidence-based risk instrument which lending institutions and insurance companies could use to justify changes in lending behaviour [6]. By bundling farm loans with WINnERS’ national crop loss insurance mechanism, the value of insurance could be recognized at a bank's portfolio level, resulting in lower collateral requirements, thus increasing the credit worthiness of smallholder farmers [E]. The insurance policy launched in Tanzania was the first to protect farmer-level needs, while being managed as a country-level risk transfer instrument.

Chavez, Makuch and Biffis worked closely with private sector institutions to form novel agreements, negotiating under the auspices of the EU’s Climate KIC programme, with each of the World Food Programme, CRDB Bank, NMB Bank, Akiba Bank, Munich Re and Private Agricultural Sector Support (PASS), a Tanzanian Trust offering credit guarantees on agribusiness loans and promoting improved local agricultural practices [F]. Willis Towers Watson conducted due diligence of the WINnERS project, noting that it would unlock a key barrier to insurance and loans for African smallholder farmers [D, E]. Munich Re and Tanzania Re, together with the WINnERS Project (Chavez, Biffis and Makuch), brought to market a cost-effective solution (35% cheaper than the closest alternative) [G].

Jubilee Insurance brokered the insurance policy in Tanzania. Three national banks placed the insurance policy in their loan programmes and PASS offered a partial guarantee for the loans. The pilots resulted in a total of $13m bank input loans and $5m of insurance coverage [H]. The decision in 2017 by MunichRe to issue a country-wide reinsurance policy for Tanzania was directly informed by Willis Towers Watson [E]. The Global Agricultural Risk Lead for MunichRe, notes in their letter that the WINnERS team’s innovations, ‘. ..tailoring insurance prices to the risk profile induced by the production technology adopted yields greater product customization, including the ability to promote climate resilient crop production’ [G].

WINnERS Pilot team members together with the World Food Programme and the World Bank, quantified the impact of the two pilots carried out during 2015-17. They estimated that a total of 50,000 Tanzanian households and nearly 400,000 individuals involved in agricultural production benefited [I]. The World Bank noted that 88% of households gained access to finance for the first time [I]. By accessing funding based on the purchase of better agricultural inputs (and associated extension services), smallholder farmers were able to double their average yield [J]. As smallholders had an average farm size of only 2.1 hectares, the boosted yield was transformational, pushing production levels considerably above the survival (and hence default) line, and allowing part of the crop proceeds to be saved and re-invested [D, H]. PASS notes in their letter, “ The presence of both insurance and credit guarantee delivered sizeable credit enhancement to smallholder farmers usually excluded from the financial system...” [K].

The success of these ventures led to three new investments developed by Chavez, Makuch and Biffis [D]. The EU Climate KIC’s second Imperial College parametric insurance investment (Arise Project €3.2 million) builds on the WINnERS approach, deepening farm-level resilience and sustainability responses. The second, funded by the New Venture Fund, deploys the de-risking solutions developed by the Imperial team to assist women farmers to access finance, promoting gender inclusion. The third project, funded by the African Development Bank, extends the de-risking solution to a larger pool of banks in Tanzania, Ghana, Uganda, Zimbabwe [L], providing financial and climate de-risking for up to 1.6 million maize and sunflower farmers. Jubilee Insurance states that Imperial’s “ novel up-scalable insurance scheme has allowed the company to expand its offering to smallholder farmers by 70% year-on-year and to reach a much larger pool of prospective customers, given the involvement in agricultural production of entire households and villages” [F].