Climate change activist Greta Thunberg
Climate change activist Greta Thunberg waves from the Malizia II boat in Plymouth, England. Image Credit: AP

New York: Swedish climate activist Greta Thunberg was due to sail into a New York harbor Wednesday after a 15-day journey crossing the Atlantic in a zero-carbon yacht.

"Land!! The lights of Long Island and New York City ahead," the 16-year-old tweeted early Wednesday alongside a dark, blurry photo of lights in the distance.

She later wrote on Twitter that her yacht had anchored off the entertainment district of Coney Island in Brooklyn to clear customs and immigration.

Thunberg is expected to dock at Manhattan's North Cove Marina near the World Trade Center around 2:15 pm (1815 GMT), according to a spokesperson.

She will make brief remarks before answering questions from journalists, the spokesperson added.

Thunberg is sailing to New York to attend a UN summit on zero emissions next month after refusing to fly there because of the carbon emissions caused by planes.

She was offered a ride on the Malizia II racing yacht skippered by Pierre Casiraghi, the son of Monaco's Princess Caroline, and German round-the-world sailor Boris Herrmann.

The yacht left Plymouth in southern England on August 14, and the teenager marked the first anniversary of the start of her school strike on August 20.

Thunberg began sitting outside the Swedish parliament in August 2018 to get members of parliament to act on climate change.

She was quickly joined by other students around the world, as word of her strike spread through the media, and the "Fridays for future" movement was born.

The 18-metre yacht features state-of-the-art solar panels on its deck and sides, and two hydro-generators provide the vessel's electricity.

Her voyage has sparked controversy however after a spokesman for Herrmann, the yacht's co-skipper, told Berlin newspaper TAZ that several people would fly into New York to help take the yacht back to Europe.

Hermann himself will also return by plane, according to the spokesman.

Team Malizia's manager insisted however that the young activist's journey would be climate neutral, as the flights would "be offset".

Thunberg has said that she does not yet know how she will return to Europe.