The 16-year-old Swedish climate change activist is going to arrive in New York City in two weeks to attend the United Nations climate summit next month and give her own warnings about the “ecological emergency” to world leaders.

Greta Thunberg, a Swedish ‘poster girl’ for the global environmentalist movement, has cast doubt on the prospect of meeting major climate change sceptic Donald Trump.

When asked by a CBS reporter whether she would like to meet with the US president, she replied: “Why should I waste time talking to him when he, of course, is not going to listen to me?”

Thunberg said she would rate the United States climate change efforts “not very high”, because carbon emissions rose again in the country for the first time since 2015.

Donald Trump, who has campaigned on a promise to revive the ailing coal industry, is a vocal denier of the science of climate change. He famously withdrew the United States from the 2015 Paris Agreement on climate change mitigation, saying that the deal would undermine America’s economy and job growth, as well as bring about declines in coal mining and other industries related to natural resources.

Thunberg, in turn, has emerged as the loudest youth voice in the international movement for climate action. She came to international prominence following solitary school strikes outside Sweden’s parliament last year which saw her demand that the Swedish government reduce carbon emissions.

The girl – who has been nominated for the Nobel Peace Prize – has launched the Fridays for Future movement, which encourages students worldwide to skip school in order to take part in demonstrations for climate protection.

The teenage activist wants to get adults on board too. As she refuses to fly because of the environmental impact of aviation, she is setting sail for New York from Plymouth on a two-week voyage by boat to address world leaders at the upcoming UN Climate Action Summit.

But some people, including politicians, criticise her passion for tackling climate change for her perceived alarmism or naivety.

Last month, for instance, some conservative legislators boycotted her speech at the French parliament, calling Thunberg a “prophetess in shorts” and a “guru of the apocalypse”.