Climate activist Greta Thunberg has said her voyage across the Atlantic in a racing yacht to attend UN summits in New York and Chile on tackling global warming was going to be a “huge challenge”.

The 16-year-old is making the trip across the Atlantic on a high-tech racing yacht, the Malizia II, so she can attend high-profile climate events without using planes or cruise ships which emit greenhouse gas emissions.

The Swedish teenager’s “school strikes” have inspired a global protest movement by young people demanding urgent action on climate change.

Climate activist Greta Thunberg addresses a press conference in Plymouth (Ben Birchall/PA).
Climate activist Greta Thunberg addresses a press conference in Plymouth (Ben Birchall/PA)

The teenager said her two-week trip would have challenges including seasickness but said many people in the world were suffering a lot more than that.

“I was test sailing two days ago and we went out for several hours. I didn’t feel bad or anxious, I felt seasick for about one or two minutes, then it stopped,” Greta said, ahead of her departure from Plymouth, Devon.

“I will just have to see, get on the boat and see what happens, and that is also very exciting.

“I’ve never done anything like this before, I can’t really say what’s going to be the biggest challenge, I will have to find that out.”

The first anniversary of her protest movement will happen next week while she is sailing.

Explaining why she started, she said: “In the beginning, my voice wasn’t heard at all, I tried different ways until I found some kind of method that made my voice heard.

“It’s individual for everyone, you have to be creative and come up with something new to do, there’s so many things.

“It’s such an incredibly big and global problem, it needs to be tackled from every possible angle.”

On climate sceptics, Greta said: “There’s always going to be people who don’t understand or accept the united science, and I will just ignore them, as I’m only acting and communicating on the science.”

Asked where she gets her energy from, she said: “I know this is a very big problem, I have read a lot and I understand the problem in many ways.

“I have just decided I’m going to do everything I can, that keeps me going, the dedication I will do everything I can.

“Also the fact that some things are actually changing, I think the mindsets of many people are changing, even if it’s not enough, and not fast enough, that’s something, it’s not for nothing.”

Greta, who is taking a sabbatical year from school, will be joining large-scale climate demonstrations and speaking at the UN Climate Action Summit hosted by secretary-general Antonio Guterres in New York in September.

She is also planning to visit Canada and Mexico before travelling to this year’s UN climate conference, which is taking place in Santiago, Chile, in December, making her journeys by train and bus.

The youngster is crossing the Atlantic in the 60ft sailing yacht, which is fitted with solar panels and underwater turbines to generate zero-carbon electricity on board.

The vessel is captained by Boris Herrmann, and Greta will also be accompanied on the two-week journey by a filmmaker, her father Svante and Pierre Casiraghi, the grandson of Monaco’s late Prince Rainier III and American actress Grace Kelly.