Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Greta Thunberg Says Sea Voyage 'Energized' Her Climate Fight Associated Press LISBON, PORTUGAL - Climate activist Greta Thunberg arrived in Portugal on Tuesday after a three-week voyage across the Atlantic Ocean, telling cheering supporters that the journey had "energized" her for the fight against climate change. The Swedish teen, whose one-woman protests outside the Swedish parliament helped inspire a global youth movement, sailed into the port of Lisbon after making a last-minute dash back from the United States to attend this year's U.N. climate conference. Thunberg has been steadfast in her refusal to fly because of the amount of greenhouse gases emitted by planes, a stance that put her planned appearance at the meeting in doubt when the venue was moved from Chile to Spain a month ago. "We've all been on quite an adventure," Thunberg told reporters shortly after stepping off the catamaran La Vagabonde, on which she'd hitched a ride back home to Europe. "It feels good to be back." Thunberg's appearances at past climate meetings have won her plaudits from some leaders - and criticism from others who've taken offense at the angry tone of her speeches. "I think people are underestimating the force of angry kids,'" Thunberg said. "If they want us to stop being angry, then maybe they should stop making us angry." The 16-year-old said she planned to spend several days in the Portuguese capital before heading to Madrid, where delegates from nearly 200 countries are discussing how to tackle global warming. "We will continue the fight there to make sure that within those walls the voices of the people are being heard," she said. The white 48-foot (15-meter) yacht carrying Thunberg, her father Svante, an Australian family and professional sailor Nikki Henderson sailed into Lisbon amid blue skies, with a small flotilla of boats escorting it to harbor. .