Image: Dired Dawa sludge disposal site. Credit: Abraham Geremew.

The challenge

Sustainable Development Goal 6 aims to ensure universal access to sanitation. But sanitation systems are an important source of the greenhouse gas emissions that are driving climate change, and as the climate changes new challenges are emerging about how to ensure services are resilient. Globally, the vast majority of people who have access to a toilet (and over 600 million people still lack any form of toilet) use technologies that manage waste on-site such as latrines and septic tanks. 

But at present, the tools used to estimate greenhouse gases from sanitation are geared towards sewers and sewage treatment works, and primarily designed for those systems found in temperate climates. These tools don’t work well for on-site sanitation and in particular simple latrines and tanks found in tropical climates. This is important because one estimate suggests that 1% of global emissions may come from on-site sanitation, while a study in one African city suggested that 40% of the total emissions from the city came from on-site sanitation. If we can measure emissions from on-site sanitation more reliably then we can identify technical and operational solutions that will minimise emissions while still protecting public health. In turn this may make it easier for governments and their partners tp access climate finance to fund better sanitation that provide climate and health co-benefits. 

At the same time, many sanitation systems are at increasing risk from climate-related hazards including: flooding which flood latrine pits and septic tanks releasing faeces into the environment; extended droughts that make accessing enough water to flush toilets regularly difficult; excessive rain that leads to landslips and latrines being destroyed; and floods and landslips that interrupt supply chains and prevent pits from being emptied when they are full. Maintaining access to sanitation under a changing climate means we need to understand more clearly how we make sanitation more resilient to climate threats. 

What we're doing

With funding from the Bill and Melinda Gates Foundation, we are working with partners to undertake work in Nepal, Ethiopia, Uganda and Senegal to measure greenhouse gases from on-site sanitation in different climates and in different seasons. This will provide the first empirical evidence of emissions from these systems from low- and middle-income countries and will be used to refine tools and methods for making more accurate estimates of emissions that can be reported in Nationally Determined Contributions submitted to the UNFCCC. We will identify what options exist to reduce emissions and provide guidance on how to develop climate and health co-benefits. We will also assess the resilience of sanitation systems, using the metrics developed under the How tough is WASH project. We aim to develop guidance for governments, UN agencies and NGOs working on sanitation about how to improve resilience and develop criteria for climate funds to use to assess WASH proposals for climate adaptation finance.  

How it helps

The tools and methods we are developing will allow decision makers to make better decisions about sanitation services in terms of technology selection, operations, and policy. This evidence will also help governments and their partners to prepare better proposals to climate funds that set out co-benefits available from investment in lower carbon, more resilient sanitation. For more information, visit the website: Sanitation and climate: assessing resilience and emissions (SCARE). 

Investigators

• Professor Guy Howard, Global Research Chair Environmental and Infrastructure Resilience