Carbon dioxide removal by enhanced weathering on American green clay tennis courts

[Geoengineering News]

https://www.sciencedirect.com/science/article/abs/pii/S0883292726000612

Authors: Frank J. Pavia, Jonathan E. Lambert

21 February 2026

https://doi.org/10.1016/j.apgeochem.2026.106737

Highlights

•Green clay tennis courts are a sink for atmospheric CO2 through weathering reactions with their metabasalt feedstock.

•We model CO2 uptake on green clay tennis courts, taking into account location, grain size, and emissions during construction.

•Green clay courts in the U.S. sequester >25,000 tonnes of CO2 per year and 80% of green clay courts generate net negative emissions within 10 years.

•Life-cycle analysis reveals that U.S. green clay tennis courts have substantially lower emissions during construction than hard courts.

•Replacing existing hard courts with green clay courts can generate quantifiable, additional CO2 drawdown.

Abstract

40,000 tennis courts in the United States are constructed and maintained by spreading basalt feedstock similar to that used for carbon dioxide removal via enhanced rock weathering. Silicate weathering therefore readily occurs on these courts, yet the carbon sequestration associated with this weathering has never been quantified. We have built a model that quantifies net CO2 sequestration during the lifetime of green clay tennis courts. We calculate gross CO2 sequestration rates associated with silicate weathering and conduct a lifecycle analysis for emissions during court construction. This allows us to determine net sequestration rates at each court as well as assess the factors that lead to maximal CO2 sequestration at different sites. We find that transportation distance from the singular Blue Ridge metabasalt processing site is the primary source of emissions for most tennis courts. Taking all factors into account, green clay tennis courts sequester over 25,000 tonnes of CO2 per year and the median court becomes net CO2 negative in 3.5 years. Our emissions analysis also shows that green clay tennis court construction emits 1.6-3 times less carbon dioxide than hard courts do over their entire life cycle. We conclude by discussing the potential for changes in feedstock characteristics and green clay tennis court maintenance practices that can further reduce their carbon footprint and the pathway towards producing verifiable carbon removals on green clay tennis courts.

Source: ScienceDirect