Tropical ecosystems store vast carbon pools, which are potentially highly vulnerable under the climate change scenarios likely to play out over the coming century. Methane production from wetlands is highly temperature sensitive, for example and prolonged dry spells may result in hotter and more extensive biomass burning during the dry season. Both mechanisms could displace long-stable land surface carbon pools into atmospheric greenhouse gases, acting as a positive feedback on the climate system. Despite this, there are few high-quality greenhouse gas observations in tropical regions.

Since 2018, CSIRO has renewed its atmospheric composition measurements at the Northern Territory Baseline Air Pollution Station (NT BAPS) at Gunn Point, through engagement with the Larrakia Rangers. The Rangers conduct monthly flask sampling for CSIRO’s Global Flask Network and undertake routine site visits to support the in-situ measurements of carbon dioxide, methane and carbon monoxide.

Drawing on work previously co-produced between CSIRO and Larrakia Elders, led by Lorraine Williams [1] the collaboration with the rangers has deepened to include a joint exploration of how the observed seasonality in greenhouse gas mixing ratios corresponds to the Indigenous understanding of seasons on Larrakia country. This talk will present some of the deeper understanding of the regional greenhouse gas signals arising from this more nuanced perspective of seasonality in the Top End.

1. Williams, L., Williams, J., Ogden, J., Risk, K., Risk, A. and Woodward, E. (2012). Gulumoerrgin Seasons (calendar), Larrakia, Northern Territory, Australia. CSIRO Ecosystem Sciences, Darwin.