Protesters in New York City brought traffic to a standstill in the city's busiest hub and an activist in London climbed atop a plane as climate change demonstrators entered the fourth day of rallies around the world.
Protesters transported a green boat on a trailer into Times Square and then sat down and refused police orders to move.
The boat bore the logo of the activist group Extinction Rebellion. It also had the words "Act Now" written on it and a string of brightly colored flags.
Some of the demonstrators carried signs in the shape of orange rescue lifebuoys, with the words, "Save our Future."
The New York Police Department made dozens of civil disobedience arrests and removed the vessel some time later, which led to re-opened area streets and brought the traffic back to normal.
In London, a climate change activist scaled a British Airways plane at London City Airport. Extinction Rebellion identified the activist as a former Paralympic cyclist. A video streamed by the group showed the activist clinging to the fuselage.
British Airways says that customers were booked onto alternative flights to Amsterdam.
In a separate incident, BBC Newsnight political editor Nicholas Watt tweeted that his flight from London to Dublin had been grounded after a protester stood up to deliver a lecture on climate change just as it was to take off.
Activists sought to shut down London City Airport on Thursday as part of their wave of protests worldwide.
The environmental protests have been taking place in cities around the world.
The group got its start in London last year, and has since spread to other countries.