Martinez et al. tested three different Roman concrete recipes with varying slaked lime-to-pozzolan ratios (1:2, 1:3, and 1:4), and assessed greenhouse gas and air emissions for each production stage based on known Roman construction practices. The results surprised the scientists. Per volume of concrete, the production process for Roman concrete ended up emitting as much and, in some cases, more CO2 than modern formulations.
The Complete Streets project along Richmond Street aims to lower car speeds and improve pedestrian safety through various installations including raised intersections, corner extensions, and flashing crosswalk signals.
"I think this is one of those key moments that is extremely upsetting and yet super predictable, which is that the energy planning and the poor decisions that get made five, eight years prior to that now are starting to show up in those supply mixes."
California's Cap-and-Trade program has raised $33 billion since 2014, directing funds to both combat climate change and support communities, primarily focusing on low-income areas.