Professor David C. Wilson
Waste & Resources Management Consultant
Visiting Professor in Waste Management
Imperial College, London

News & Updates

Measuring black carbon emissions from open burning of waste

Black carbon (BC) emissions from the open burning of municipal solid wastes (MSW) and other waste types contribute significantly to global heating but are not yet included in the official (IPCC) inventory of greenhouse gases (GHGs) due to poor data availability. Natalia Reyna has just completed her PhD thesis at Imperial College London, co-supervised by Professors David C Wilson and Stephen R. Smith, with the aim of generating reliable data to plug that gap. Our second and final paper was published last week in the leading journal Atmospheric Environment, providing a reliable methodology for measuring emission factors (EFs) for black carbon from waste burning. Our best estimate of the contribution of BC from the open burning of MSW to global heating is in the range 2-10% of global CO₂Eq emissions. Given the associated air pollution and health impacts, urgent global action is essential to eliminate open burning of waste; this will provide a relatively ‘quick win’ in tackling the climate emergency. The Atmospheric Environment paper is available to download free of charge until 24 August 2019.

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Benchmarking performance of SWM systems in East Africa

Professor David C Wilson has been working for the last two years with the Rwandan academic Telesphore Kabera to apply the Wasteaware indicators to benchmark performance of the solid waste management (SWM) and recycling system in Kigali, the capital of Rwanda. Their results form the basis of a paper published today in the first ever open access issue of the long established ISWA peer-reviewed journal Waste Management & Research. The paper uses previously unpublished results from the Wasteaware database to compare Kigali’s performance with four other East African capital cities – Dar-es-Salaam, Kampala, Nairobi and Maputo.

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DCW looks back on his CIWM Presidential year

Professor David C. Wilson’s final contribution to the CIWM Journal took the form of an interview in which he looked back on his Presidential year. This web-posting also includes an index of and links to his monthly columns for the CIWM journal, many of which were ‘think-pieces’ on issues in which he has been involved for years or even decades. Among the questions covered in the final interview were: has any topic dominated the year (yes, plastics – both marine plastics and the ‘China ban’); and what would be your advice to Enda Kiernan and future CIWM Presidents (‘Be true to yourself’ – which the editor also used as this month’s headline).

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DCW awards his Presidential Medal

At the CIWM Presidential Dinner at the Intercontinental Hotel in Dublin, after the inauguration of Enda Kiernan as the next President, DCW’s last act as the retiring President was to award his CIWM Presidential Medal for 2018. The recipient was Mike Webster, the founder and CEO of the new charity Wasteaid, which is working directly with local communities in some of the least developed countries to tackle the global waste crisis. The text of DCW’s speech is reproduced below.

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DCW hands over the CIWM Presidency

Professor David C Wilson handed over the Presidency of CIWM, the UK and Irish professional body for resources and waste, to Enda Kiernan at the Aviva Stadium in Dublin on 13 November 2018. He highlighted plastics – both plastics entering the oceans and China’s ban on imports for recycling – as the dominant topic in his Presidential year. The public focus on marine plastics also helped dissemination of his Presidential report, the CIWM-Wasteaid Toolkit Making Waste Work; the website clocked 56,000 visits in its first year, with 7,000 downloads. DCW introduced his fellow Irishman, Enda Kiernan of Cork County Council as the next President. CIWM waited more than a century for its first Irish President; now we have had three in five years, and two in a row, although Enda is the first from the Republic of Ireland.

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Plastics – diabolic or fantastic?

In his October column for the CIWM Journal, Professor David C Wilson reflects on the dominant story of his CIWM Presidential year, how we respond to the crisis of plastics entering our oceans. Which plastic uses are diabolic and should be banned, and which do we really need? One of his starting points was a recent CIWM-sponsored report which proposed a five-fold use-based categorisation of plastics. The other was the July Klosters Forum, which gathered 60 stakeholders from around the World to brainstorm on how to stem the flow of plastics into the oceans.

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Tackling the global waste crisis through community waste management

Three billion people lack access to basic solid waste management services; addressing this problem would not only vastly improve their lives but also halve the weight of plastics entering the oceans. Professor David C Wilson and Mike Webster of Wasteaid made the case earlier this year, in an open access editorial in the ISWA journal Waste Management & Research, for community waste management as a ‘bottom up’ approach, to run in parallel to traditional ‘top-down’ approaches led by donors and governments. Community waste management requires building capacity at the local level. This is underpinned both by practical guidance, provided by the 2017 CIWM-Wasteaid Toolkit Making Waste Work; and by scientific understanding of the simple technologies in the toolkit. With our colleagues at Imperial College London, we have this month published a paper on optimising the technology for producing plastic bonded sand blocks from the low value LDPE film plastic, which is a major problem even in the least-developed countries.

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Charge! – Paying for household waste services

CIWM President and lifelong waste policy and planning consultant David C Wilson reflects in his September column for the CIWM Journal on the challenges of devising the right policies to charge households for solid waste management services. Of course, we already pay for our solid waste services, but that charge is usually hidden within a wider charge or tax, which in the UK is council tax. Across Europe, many local authorities have been experimenting over the last 20 years with pay-as-you-throw (PAYT) systems, where the charge varies at least in part according to usage. The growing evidence base suggests that PAYT does work, in terms of reducing waste quantities and increasing recycling. But why should local authorities, and ultimately households, pay for all the costs of municipal solid waste management? Particularly in the context of Defra’s forthcoming Resources and Waste Strategy for England, DCW argues for real Extended Producer Responsibility (EPR), with teeth, that will move the full financial burden of collecting, recycling and disposing of packaging and other products in the municipal waste stream from local authorities to the producers and supply chain. If we cannot have PAYT, let us at least have PAYB (pay-as-you-buy).

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Hazardous Waste – Plus ça Change

CIWM President, and Chair of CIWM’s Hazardous Waste Special Interest Group (SIG), David C Wilson reflects in his August CIWM column on the challenges facing hazardous waste management in the UK and Ireland – past, present and future. His review with the SIG of current challenges suggests that not much has changed over the 44 years of his involvement with the hazardous waste sector. In particular, the UK continues to lack the ‘regulatory certainty’ which is necessary to secure the investment required in hazardous waste management infrastructure if such investment is left entirely to ‘the market’. And looking at the island of Ireland in particular, the uncertainties around Brexit do not help.

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Don’t waste our climate

In his July column, CIWM President David C Wilson makes the case for more investment in resource and waste management as an ‘entry point’ to achieve significant climate mitigation. The sector already has a track record in developed countries, with methane mitigation from landfill since the 1970s, and both methane mitigation and recycling making a major contribution to meeting Kyoto Convention greenhouse gas (GHG) reduction targets between 1990 and 2010. But that early success also means that the IPCC’s 2010 assessment is that the ‘waste’ sector only contributes 3-5% to current GHG emissions. DCW argues that this is a gross underestimate which fails to consider: the current emissions from uncontrolled burning; historical reductions; contributions across the economy from recycling; and waste prevention (particularly food waste). The results suggest that better resource and waste management has the potential for reducing GHG emissions across the World economy by 15, 20 or 25% or even more. Such numbers may be guesstimates, but whatever number we choose to use, the message is still the same. Further investment in this sector, in both developing and developed countries, is a major political priority in order to meet our climate targets.

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CIWM success in influencing policy

DCW’s Presidential year at CIWM continues to be dominated by marine plastics. As part of our efforts to influence developing UK policy in this area, CIWM and Wasteaid published a report: ‘FROM THE LAND TO THE SEA: How better solid waste management can improve the lives of the world’s poorest and halve the quantity of plastic entering the oceans’. His June CIWM column reports success: the day before the biennial Commonwealth Heads of Government Meeting in London in April, Theresa May announced a new Commonwealth Clean Oceans Alliance (CCOA) backed by a £61.4 million funding package of funding to help tackle marine plastics, of which more than £20 million would help developing country members of the CCOA improve waste management at a national and city level.

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Revaluing Recycling

Europe and North America have a problem with sustainable recycling. China’s ban on imports has thrown the problem into sharp focus: where are the markets for the materials we are collecting for recycling to meet the targets? And how do local authorities balance their already curtailed budgets as prices for recycled materials plummet? DCW’s May CIWM column explores the history of recycling over the last 40 years, and concludes that our existing policy support measures, focusing on increasing supply rather than demand, are not fit for purpose. He argues that we need to rethink recycling to make it a sustainable foundation for our future circular economy; and makes the case for considering explicitly the embodied social, environmental and technical values alongside the market price.

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Uncontrolled burning of solid waste as a significant contributor to climate change

To qualify for inclusion in the official (IPCC) inventory of greenhouse gases (GHGs), data for an emission source must meet a quality threshold. This currently excludes black carbon emissions from the open burning of wastes. The relative quantities may be small compared to carbon dioxide from fossil fuels or methane from landfill, but black carbon is around 2,000 more powerful than CO₂ as a GHG. In the absence of real data, early modelling studies using broad assumptions suggested that black carbon from open burning contributes 5% of total global GHG emissions, causing 270,000 premature deaths a year. DCW’s PhD student at Imperial College London, Natalia Reyna, has been working for the last four years to provide real data which would meet the IPCC requirements. Our first paper, published this month in the leading journal Environmental Research, presents field data from Mexico on how much solid wastes are disposed of by open burning, either by households or at uncontrolled dumpsites. The results suggest a GHG contribution from uncontrolled burning in backyards in Mexico fifteen times larger compared to methane released from the decomposition of equivalent amounts of waste in a disposal site. A future paper will present data on emission factors, i.e. how much black carbon is produced by burning a kilogram of waste.

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China: Coming Full Circle

China’s recent import ban has thrown Western recycling systems into disarray. DCW has participated as CIWM President in three regional open meetings to address the ‘China recycling crisis’. His April column for the CIWM Journal has written up his presentation, providing a personal perspective on how he has seen China’s internal resource and waste management systems develop over the last 40 years. Arguably, its 1970s system could be viewed as an early example of a circular economy. The transition to ‘market -oriented’ operations led to economic growth being prioritised over environmental protection. But the current ‘National Sword’ campaign is just one symptom of a fundamental change, suggesting that, going forward, perhaps China really could lead the world in transitioning to a circular economy.

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Let’s Skip ‘The Tip’

Language matters. DCW’s March column for the CIWM Journal celebrates the dramatic improvements in waste and resource management that have been achieved since he first entered the sector in 1974. This is largely due to changes in public behaviour, which have enabled the UK, for example, to increase recycling rates over the last 20 years from just 6% to 46%. However, he questions how we can expect people’s mind set to change permanently when some local authorities, and both professionals and politicians, continue to refer to modern recycling facilities as ‘the rubbish tip’.

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Turning the Tide

DCW’s February column for the CIWM Journal focused on the topical subject of marine plastics. He reported back on ‘Oceans 21’, the latest Development Finance Forum organised by the German Development Bank KfW, where he led a workshop on marine litter. The conclusions were clear: the amount of plastics entering the oceans is at least an order of magnitude greater than estimates of the visible quantities in the oceans or on beaches – so the first priority is to ‘turn off the tap’. And the most effective way to do that is to extend municipal solid waste collection in developing countries to all people and to eliminate uncontrolled dumping and burning; our best judgement was that this could reduce the weight of plastics entering the oceans by 50-70%.

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Inspiring Reuse

DCW’s January column for the CIWM Journal showcases the five shortlisted entries for the Best Reuse Project at the CIWM Sustainability and Resource Awards 2017. As the judge for this category, DCW was inspired by the quality and sheer variety of the five very different reuse projects. He hopes that the projects will inspire others too, as we try to ensure that reuse, sitting near the top of the waste hierarchy, receives the same priority as has been given to recycling.

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A key utility service

In his first monthly column in the CIWM Journal as CIWM President, Professor David C. Wilson has revisited his Presidential address. His overall theme for his year is solid waste management as a key utility service, underpinning modern society. Within that three strands are to avoid complacency when it comes to protecting public health and the environment; the continuing move from the linear ‘make – use – dispose’ model to a more circular economy; and the global waste crisis, with more than 3 billion people lacking access to a basic solid waste management service.

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