To handle the pandemic, the nation will need 30 contact tracers for every 100,000 Americans so for now many cities are only tracking the virus's spread through vulnerable populations.
Trump's loosening of fuel economy standards means that cars will be allowed to emit more climate-warming carbon dioxide as well as pollutants that cause smog and other air pollution.
California’s scientists are sheltering in place because of coronavirus restrictions, shutting down research, or switching to study the novel coronavirus.
Streamlined reporting adds to the tally of tests for the novel coronavirus conducted in California - but results are still pending for tens of thousands of them.
Gov. Gavin Newsom has said that if as many coronavirus patients as feared need hospitalization, surge capacity could be outstripped by up to 10,000 beds.
On Wednesday, President Trump is expected to roll back Obama-era standards, jeopardizing a decades-old exemption that lets California make its own clean air rules.