• Video report by ITV News Science Editor Tom Clarke

Teen climate activist Greta Thunberg, who became a global conscience for environmental change, has been named Time Magazine’s Person of the Year for 2019.

The 16-year-old started a movement to fight climate change after protesting alone outside the Swedish parliament during school hours on Fridays when she was just 15 years old.

The teen held up a now world recognised hand painted sign that read "skolstrejk för klimatet," which translates to "School strike for the Climate."

She continued to highlight the climate crisis globally which also sparked the "Fridays For Future" movement across the world.

Time's Editor-In-Chief wrote that Ms Thunberg was chosen "for showing us all what it might look like when a new generation leads."

Edward Felsenthal wrote: "For sounding the alarm about humanity’s predatory relationship with the only home we have, for bringing to a fragmented world a voice that transcends backgrounds and borders, for showing us all what it might look like when a new generation leads, Greta Thunberg is TIME’s 2019 Person of the Year."

Earlier on Wednesday, Greta compared governments' failure to properly tackle climate change to watching a car travel at full-speed while a child stands in the road.

During a speech at the COP25 in Madrid, the Swedish teenager said leaders were failing the people who elected them by not taking the problems posed by climate change seriously.

She said: "The lack of awareness is the same everywhere.

"Not least among those elected to lead us. There is no sense of urgency whatsoever."

She added: "In an emergency, you change your behaviour. If there is a child in the middle of the road and cars start coming at full speed, you don't look away because it's too uncomfortable.

"You immediately run out and rescue that child. And without that sense of urgency, how can we, the people, understand that we are facing a real crisis?"

Activist Greta Thunberg compared government's failure to properly tackle climate change to watching a car travel at full-speed while a child stands in the road. Credit: AP

Greta said science showed that the current emissions proved the world is set to use up the whole "carbon budget" - the amount of pollution that can be put into the atmosphere and still keep global warming to 1.5C – in eight years.

Countries previously committed to curbing global warming at “well below” 2C above pre-industrial levels and to pursue efforts to keep temperature rises to 1.5C in the Paris Agreement secured in 2015.

Governments meeting at the talks are now under pressure to take more ambitious action to cut greenhouse gases, which continue to rise, to avoid the worst effects of climate change.

Greta warned that “even at 1C people are dying from the climate crisis” and the science showed that going beyond 1.5C risks destabilising the climate and hitting irreversible tipping points such as melting glaciers and permafrost.

She said: “Finding holistic solutions is what the COP should be all about, but instead it seems to have turned some kind of opportunity for countries to negotiate loopholes and to avoid raising their ambition.

Swedish activist Greta Thunberg addresses leading climate scientists at the COP25 summit in Madrid, Spain Credit: Paul White/AP

“Countries are finding clever ways around having to take real action, like double-counting emissions reductions, and moving emissions overseas, and walking back on their promises to increase ambitions, or refusing to pay for solutions or loss and damage.

“This has to stop.”

Greta, who sailed across the Atlantic to attend the talks in Chile, before having to sail back again because they were moved to Spain due to civil unrest in the South American country, has made a series of hard-hitting speeches at international events in the past year.

In her latest talk, she focused on the science and the “misleading” behaviour of politicians and big business.

She said countries which had committed to reducing their emissions to zero by a certain date, as the UK has done with its legally binding pledge for net-zero by 2050, appeared impressive at first glance.

But “this is not leading, this is misleading”, she said, warning that the targets did not include aviation and shipping, or the emissions created by goods made in other countries and imported – and did include “offsetting” emissions.

“Zero by 2050 means nothing if high emissions continue for even a few years. Then the remaining budget will be gone.”

She said real, drastic emissions cuts were needed, and carbon had to stay in the ground to keep temperature rises below 1.5C.