Thunberg: We can still fix climate, but must start today

"We are about 500 million people living in the EU and we use about one fifth of the world's resources. What we do in the EU has enormous impact for future living conditions on this planet," she said.

"Of course you would think the EU elections should be about this", she said: "But it is not".

"In fact, global emissions are still rising. Despite all the beautiful words and promises of our leaders and politicians," she told the cheering crowds.

It was the young Swede's first public appearance in Denmark where her climate activism has struck a strong nerve among young people and prompted school strikes on Fridays, just like in many other cities around the world.

In particular, girls aged 10-12 were present in the thousands at the march on Saturday in Copenhagen, whereas fewer young boys were seen in the crowds.

It was one of the biggest public demonstrations for years in Copenhagen, gathering 40,000 people, according to police estimates.

But Thunberg did not offer much praise for the climate efforts of the city, which housed the 2009 United Nations climate change conference and has announced it will become the world's first carbon-neutral capital city by 2025.

"Words like carbon-neutral Copenhagen 2025 sounds really beautiful, but if it does not include transportation, shopping, food, aviation and shipping, then it does not really mean that much," she said.

"Sending these messages that real action is going on when it really is not does probably more harm than good," the young climate campaigner said tot huge applause from the Copenhagen residents.

"Elections should be all about this," Thunberg said.

"Those going to be affected the most by the climate and ecological crisis, young people like me - can not vote. So if not for yourself, then vote for us," she said.

"We can still fix this, but we must start today".

The EU's first climate commissioner, former conservative politician, Connie Hedegaard, also spoke at the rally.

She is no longer active in politics, but has continued her green battle from within the board rooms of large companies and foundations.

Speaking alongside Thunberg in Copenhagen on Saturday, Hedegaard struck a more positive note.

"Words are no longer enough. We want to see action," she said and praised that climate is now on top of the political agenda and that there will be binding five-year climate goals resulting from the next Danish national elections.

The Danish agro-industry recently signed up to CO2 neutral targets under pressure from Danish consumers rapid change of eating and shopping behaviour, reducing meat consumption.

She also noted that Volkswagen, the worlds largest car maker, has put a due-date for production of the last fossil-fuel driven car and has started to invest massively in development of electrical cars.

It has probably been a long time since the diesel scandal hit Volkswagen last time got a huge round of public applause. But it happened in Copenhagen on Saturday.

EU investors must in future demonstrate the climate impact of their investments, public investments must be green, Hedegaard said and added, as another positive development, that 23 central bank directors, including the Danish one, recently pledged to include climate risks into economical calculations.

"Public pressure and political engagement move things", Hedegaard said.

Denmark does not have a Green party, but the climate issue has climbed to be top of the agenda for most political parties.

The other big issue in Danish elections relates to border and migration control, pushed by the Danish People's party and two new further to the right parties, running for national elections.

The latest polls predict the Social Democrats and the Liberal parties will do best in Sunday's EU elections, with the Danish people's party losing two of the four mandates it scored in the last EU elections in 2014.

Denmark elects 13 MEPs and will get one extra seat when the UK leaves the EU.