Fans of Greta Thunberg have expressed relief after the 16-year-old posted a string of smiling photographs on Instagram.

The environmental activist's recent images, taken while touring Canada's east coast in Montreal and Quebec, are in sharp contrast to images of the 16-year-old speaking in an emotionally charged appearance last month at the Climate Action Summit 2019 in New York. A photo of Greta scowling when she spotted Donald Trump went viral.

The teenage campaigner, who has 7.2million followers on Instagram, looks decidedly happier since she crossed the border from the US, something which her followers haven't failed to notice.

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Teenage eco-activist Greta Thunberg has posted a series of smiling photographs during her tour of eastern Canada, including this photo at a farm in Quebec

The recent photos offer a sharp contrast to Greta's appearance at the United Nations Climate Summit on September 23rd, where she was spotted glaring at President Trump

At the Climate Action Summit 2019 in New York last month, the 16-year-old called out the leaders gathered there saying: 'I shouldn't be up here. I should be back in school. You have stolen my dreams and childhood'

The teenager told her 7.2million followers on Instagram that she was 'so happy' to be travelling slowly through the North American continent

Writing on Instagram, Greta said: 'So happy to say that the following weeks I'll travel slowly through the North American continent, moving southwest and then eventually through South America towards Santiago. I will stop on the way and visit as many places as I can, and of course protest every Friday no matter where I am.'

Yesterday the teenager posted an image of herself at the Marine Mammal Interpretation Centre in Tadoussac, Québec, after spending a morning watching whales.

The tone of Greta's images have changed significantly since she addressed the United Nations Climate Summit on September 23rd, where she came close to tears in a emotional speech to international delegates.

She told them: 'I shouldn't be up here. I should be back in school on the other side of the ocean. Yet you all come to us for hope. How dare you. You have stolen my dreams and my childhood with your empty words,'

During the same appearance, Greta was seen at the UN headquarters with an enraged expression on her face as US President Donald Trump upstaged her entrance by walking in flanked by news reporters, an image that promptly went viral.

Around half a million people turned out in Montreal to protest against climate change last week, with Greta given the keys to the French-speaking city. Pictured with Montreal's mayor Valerie Plante

The Swedish teen photographed at the Marine Mammal Interpretation Centre in Tadoussac, Québec this week

Among the comments posted by the environmentalist's followers, many remarked how much happier the teenager had looked in recent days.

On Instagram, Jesuissuzette wrote: 'Greta, you look so much happier now that you’re out of America. Enjoy your travels. And thank you for your intrepid Climate Crisis campaign.'

Last week, Thunberg addressed on social media the negativity she's received for speaking out on climate change, saying: 'Here we go again... As you may have noticed, the haters are as active as ever - going after me, my looks, my clothes, my behaviour and my differences.

They come up with every thinkable lie and conspiracy theory. It seems they will cross every possible line to avert the focus, since they are so desperate not to talk about the climate and ecological crisis.

Being different is not an illness and the current, best available science is not opinions - it’s facts.'

Greta, who is taking a sabbatical year from school, arrived in North America in August, taking a two-week crossing on carbon neutral yacht Malizia II to address the United Nations.