Global study reveals data shortfalls in nature-based solution studies

While there is a “strong desire” across the UK water companies to account for the emissions and carbon performance of nature-based solutions in water treatment, there is limited knowledge and understanding of their greenhouse gas emissions, according to research by UKWIR.

UKWIR’s global review of the findings from research into various nature-based solutions looked at the factors that increased or decreased emissions of methane, nitrous oxide and carbon dioxide, and found most of them increased one or two emissions. But no factor raised or decreased all three greenhouse gases.

Among the shortfalls in the data available, the UKWIR researchers found that it was “challenging to identify like-for-like comparisons across the findings.”

UKWIR reported that “very few” previous studies compared the emissions from nature-based solutions with those from conventional wastewater treatment plants. Where they did, while they found that conventional plants produce “much more” climate-changing gases, other factors such as the land used and population equivalents were not taken into account.

Most research on the topic, UKWIR said, had been undertaken in Asia, with few published findings for the UK.

UKWIR concluded there was a need for more research that compared nature-based methods with conventional treatments, “particularly in the UK and Irish context.”  Other studies should include lifetime assessments of nature-based solutions and screening of constructed wetland plants that balance pollutant removal; and reduction of emissions.