When Arnold Schwarzenegger was governor of California, he backed environmental legislation that led to one of the world’s most closely watched initiatives in the fight against global warming. On Tuesday, Schwarzenegger joined his successor, Jerry Brown, as Brown signed legislation that kept alive a cap and trade program that both men have urged the rest of the world to emulate. The program puts a cap and a price on carbon emissions, creating an incentive for polluters to reduce emissions.

For the first time in 11 years, Lake Tahoe is nearing capacity thanks to snow melt coming off of the Sierra Nevada mountains. The lake level peaked at 6,229 feet on July 9, coming extremely close to its full capacity level of 6,229.1, which hasn’t been reached in over a decade, SF Gate reported. The waterway has managed to flourish despite increased evaporation on its surface. In the summer, evaporation from lakes like Tahoe is generally more efficient due to windier and warmer conditions, according to weather.com meteorologist Jonathan Belles.

A new report from a UC Berkeley group researching what caused the Lake Oroville spillway to fail in February is concerned that a green spot on the nation’s tallest dam might mean it is leaking. This is not the first time the “green spot” on the southern end of Oroville Dam has been brought up. It has been asked and answered at community meetings, where state Department of Water Resources officials have said it is caused by rain or is a natural spring. Robert Bea and his team at UC Berkeley are far from convinced.

Los Angeles is restoring a century-old water tunnel to capture runoff from the Sierra Nevada, which had a record snowfall this winter after years of drought. The Department of Water and Power is spending $4.5 million to repair and reopen a 2-mile-long tunnel that once carried water from the Los Angeles Aqueduct to a now-defunct reservoir, the Los Angeles Daily News reported. The tunnel is part of the Maclay Highline system of channels and tunnels that supplied water to homes and farms in Sylmar and the Sunland-Tujunga area.

California, which has long been a pioneer in fighting climate change, renewed its commitment to reducing greenhouse gas emissions last week by extending, to 2030, its cap-and-trade program, which effectively puts a price on emissions. It’s a bold, bipartisan commitment that invites similarly ambitious policies from other states, and it sends a strong signal to the world that millions of Americans regard with utmost seriousness a threat the Trump administration refuses to acknowledge, let alone reckon with.