Rallies, walks and events were planned Friday in San Diego to participate in a global effort to bring awareness to the climate change.
Crowds of people are gathering in cities around the country including New York and Chicago for a global climate strike designed to put pressure on lawmakers ahead of next week's United Nations climate action summit.
The inspiration behind Friday's strike comes from Swedish 16-year-old Greta Thunberg, who single-handedly protested outside of parliament, demanding that lawmakers in her country treat climate change as a top priority.
Nations around the world agreed at a 2015 summit in Paris to hold warming to less than 2 degrees Celsius (3.6 Fahrenheit) more than pre-industrial-era levels by the end of this century.
But President Donald Trump subsequently announced that he was withdrawing the U.S. from the agreement, which he said benefited other nations at the expense of American businesses and taxpayers.
Trump referred to global warming as a "hoax" before becoming president. He has since said he's "not denying climate change" but is not convinced it's manmade or permanent.
The U.N. summit is aimed at eliciting concrete proposals from various countries to make progress toward the Paris goal.