Climate activist Greta Thunberg has hit back at adults who "choose to spend their time mocking and threatening teenagers and children for promoting science".
The 16-year-old from Sweden spoke at the United Nations General Assembly on Monday, and has since come under fire from the likes of US president Donald Trump.
Some commentators in America have even branded the girl behind the global school strikes movement "a mentally ill Swedish child".
But in a series of tweets on Wednesday evening, Ms Thunberg fiercely argued her case back to her detractors.
She posted: "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.
"I honestly don’t understand why adults would choose to spend their time mocking and threatening teenagers and children for promoting science, when they could do something good instead. I guess they must simply feel so threatened by us.
"But don’t waste your time giving them any more attention. The world is waking up. Change is coming wether they like it or not. See you in the streets this Friday!"
Meanwhile, Ms Thunberg used a speech in New York on Wednesday to call for political leaders to put party divisions aside and unite behind science to address the climate crisis.
"Our main enemy now is not our political opponents, our main enemy is physics. We can still fix this, it is still possible. But not if we continue like now."
