California says the state plans to launch its "own damn satellite" into orbit to address climate change.
Politicians, business leaders and celebrities will attend, and sponsors include the UN, Facebook and Google.
This climate action summit, an initiative by California Governor Jerry Brown, is crucial as it is happening midway between Paris 2015 and 2020, the UNFCCC's timeframe for dealing with mitigation of greenhouse gas emissions, adaptation and finance.
"We're going to launch our own satellite".More news: Hurricane Florence makes landfall in US North Carolina coast
With the Trump administration rolling back several climate measures - including withdrawing from the Paris climate accord - cities and states have been stepping up and making climate commitments of their own. They also risk short-term stagnation, economic and environmental.
At a signing ceremony in the state capital Sacramento, Mr Brown vowed to meet the terms of the Paris agreement and to "continue down that path to transition our economy to zero carbon emissions". California may ultimately launch multiple satellites into space, according to the governor's office.
The CEO of one of the world's largest online business software companies is urging fellow technology leaders to help fight climate change.
Gore said it's difficult to deny that climate change is causing more severe weather but that "It's a little harder to deny the 3000 deaths from the hurricane in Puerto Rico". "We're taking a stand for generations to come with our goal to double our pension investments in job-creating climate solutions".
"The president likes to talk about what a great country we are", Brainard said. "Having an eye in the sky allows us to find out who is releasing how much". "Keeping fossil fuels in the ground will", Salazar-Lopez said. "It gives us hope".More news: Pressure increase reported in MA gas pipeline, NTSB says
Ghosh said that India must use this opportunity provided by the California summit to "demonstrate its climate actions, by virtue of its power of resistance to inequities in climate politics, its power of example set through domestic policies and actions, and its power of leadership at the worldwide level, such as the global Solar Alliance".
In the United States, vehicle emissions are the single largest source of greenhouse gases.
California's satellite project will be funded by donors, including Dee and Richard Lawrence and the Jeremy and Hannelore Grantham Environmental Trust. The state is recruiting more partners.
The commitments add up to a formidable acceleration of the global clean economy, which is growing to encompass everything from the cars we drive to the food we eat to the buildings we inhabit.
"Our world is in the early stages of a sustainability revolution", former Vice President Al Gore said in a speech Friday. There are now fewer than half a million. "The idea is to ensure that all challenges issued before the GCAS to investors, businesses and cities don't just end in 2018 but build over the next two years and beyond". McDonald's is among the almost 500 companies now working with a nonprofit to slash the carbon footprint of everything it does - from beef production to packaging - to conform with the Paris goals.More news: Ian Wright's ideal response after Alan Shearer claims Arsenal aren't that good