Hundreds of thousands of students from across the globe took the lead during a day of climate protests before next week’s United Nations summit on climate change.

“We deserve a safe future and we demand a safe future,” said Greta Thunberg, a 16-year-old Swedish activist who recently raised awareness about reducing carbon footprints by sailing across the Atlantic in a racing yacht.

“Is that really too much to ask?” she told a packed crowd of schoolchildren, their parents and demonstrators in New York before addressing next week’s climate conference at the United Nations.

Organizers said 800 events were planned across the U.S., including Washington, D.C., Chicago and Los Angeles, capping off a day of rallies across the globe from Sydney to Kabul to Berlin to Istanbul. Many centered on specific goals, including stopping approvals for new mining or drilling projects and switching entirely to renewable sources of energy by 2030.

In the Solomon Islands, protests sprang up over rising sea levels. Hundreds of schoolchildren in Thailand burst into the headquarters of the environment ministry in Bangkok and then lay down to mimic their own extinction.