We need to talk about e-bikes and e-scooters: The city of Alameda encourages active transportation walking, bicycling and riding public transportation to reduce greenhouse gas emissions (GHGs) that cause global warming and sea level rise and for the health benefits. Marilyn Ezzy Ashcraft is the mayor of Alameda. (photo courtesy of Maurice Ramirez BANG archives) Transportation, primarily on-road travel, is the single largest source of GHGs in California, according to the California Air Resources Board.
In a video address to the United Nations Climate Summit on 24 September, Chinese president Xi Jinping announced that China will reduce greenhouse-gas emissions by 7% to 10% from peak levels by 2035. The pace at which China cuts emissions will have profound global impact. The country has accounted for 90% of the growth in the world's CO emissions since 2015 and it is now the largest GHG emitter in the world
When a fossil fuel is combusted, it releases energy, which boils water, which turns to steam, which drives a turbine, which generates electricity. This is an almost comically inefficient process, requiring immense amounts of material: more than 8bn tons of coal and 4tn cubic metres of fossil gas every year. And given the basic chemistry of combustion, it's unavoidable that burning all this stuff leads to an immense buildup of carbon dioxide in the atmosphere.
As fossil-fuel derivatives, plastics are made of refined carbon. By 2015, about 6.3 billion tonnes of plastic waste had been generated, with around 79% of this accumulating in landfills or the natural environment, where it breaks into ever smaller pieces. Each year, plastic production increases exponentially: the total weight of carbon in plastic has surpassed the mass of all animals combined, and is likely to equal the mass of all bacteria by 2095 (see 'Litter legacy').
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.
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.