With the end of 2019 only days away, many are taking the opportunity to look back at the year and all that's happened in it. With Twitter's general advocacy of brevity, the hashtag "#2019in5words" has been trending online.

Environmental activist Greta Thunberg, not to be left out, joined in on the trend, with her own five words summing up the year behind us and reminding us of a potentially grim future ahead, with the words, "Our house is on fire."

The tweet spread rapidly through the internet. 'Fridays for Future', the climate strike movements that Thunberg works for, shared their support by responding to the tweet with their own five words joining the trend: "We want climate action now." 

It's been quite a year for Greta Thunberg, who has been named Time's 2019 Person of the Year for her tireless efforts to spread awareness on climate change and calling worldwide leaders to take immediate and decisive action.

She has become the new face of climate change activism, especially pertaining to the voices of the youth. She has encouraged millions of people throughout the world to participate in organized climate strikes. 

According to the World Meteorological Organization, the past decade has been a "decade of exceptional global heat", with this year set to be among the top three on record.

There have been literal fires as well, most notably the flames that consumed large sections of the Amazon rainforest earlier this year, to say nothing of the fires in California, Indonesia and Australia. 

Without major changes on a global scale, the disastrous changes that are being made to global climate are unlikely to be reversed, and despite it being the holidays, Thunberg doesn't want anyone forgetting that the fight against climate change and the fight for economic sustainability is far from over.