Thurday’s profiles returned to a more typical pattern, and levels increased marginally from the previous day.

Why the high overnight values at Bellbird Park? Contrary to most reports (outer urban areas having lower carbon dioxide concentrations than city centres), we quite frequently observe high values at Bellbird Park. We cannot definitively attribute this to any specific source, but note that it is confined to night-time build-ups.  One hypothesis is that there are several potential emissions sources in the area – including a slaughter-house, two refuse stations, and at least three large-scale composting operations.  This article summarises some of what is known about emissions from composting: Nordahl, S.L. et al. (2023) ‘Greenhouse Gas and Air Pollutant Emissions from Composting’, Environmental Science & Technology, 57(6), pp. 2235–2247. Available at: https://doi.org/10.1021/acs.est.2c05846.

Please see below for a very interesting recent report from San Francisco’s BEACO2N network – which inspired our own project.  The report this last week has had significant media coverage including the Los Angeles Times, pointing out the value of such networks:

“I think the best contribution this makes is showing how we can check what’s going on,” said Danny Cullenward, a climate economist and senior fellow at the Kleinman Center for Energy Policy at the University of Pennsylvania. “It’s probably not the last word. But it’s an elegant way to ground-truth some of these things. We need more of these approaches, not fewer.”

A network of sensors that includes carbon dioxide measurement is being installed in Providence, Rhode Island, adding to the handful of cities with continuous monitoring: https://www.breatheprovidence.com/.

Globally, 2024 continues to show some exceptional temperatures. Global sea surface temperature, for example, (dark line), has only recently fallen below levels for 2023, while remaining much higher than earlier years in the data series:

Source: https://climatereanalyzer.org/clim/sst_daily/