Climate activist Greta Thunberg expressed hope on Friday UN-sponsored climate talks that kicked off in Madrid will "lead to something concrete" as she stressed the need for governments around the world to act now in the fight against climate change.

The Swedish teen said that despite mass climate protests around the world over the past year, no real action has been taken.

We have been striking now for over a year and still basically nothing has happened," she told media in the Spanish capital.

"The climate crisis is still being ignored by those in power and we can't go on like this."

When asked about the achievements of the global climate movement, Thunberg said that apart from raising public awareness about climate change "we have achieved nothing." Emissions worldwide have gone up 4 percent since the Paris Agreement in 2015. Statistics NZ data suggests New Zealand's emissions have remained static.