Climate change activist Greta Thunberg arrives aboard the yacht La Vagabonde at Santo Amaro port in Lisbon, Portugal December 3, 2019. REUTERS/Rafael Marchante

LISBON (Reuters) - Climate activist Greta Thunberg arrived in Lisbon on Tuesday after making a 20-day crossing from New York aboard the catamaran La Vagabonde, Reuters Television footage showed.

The Swedish campaigner, who refuses to travel by plane, has returned to Europe to attend the COP25 climate summit in Madrid. She was met by hundreds of supporters chanting and waving banners as her boat docked in port and she stepped ashore.