Richard Curtis has said he feels a responsibility to honour the enthusiasm of the younger “activist generation”.

The screenwriter is among 2,020 famous faces from the worlds of art, culture, sport and philanthropy backing an open letter declaring a state of “emergency” for people and the planet.

The United Nations missive is signed by 20 world-leading activists, including Nobel Peace Prize laureate Malala Yousafzai and Me Too founder Tarana Burke.

It is undersigned by 2,000 others including Dame Emma Thompson, Julia Roberts, Saoirse Ronan, Ryan Reynolds, Rami Malek, Coldplay’s Chris Martin and Bear Grylls.

Curtis, 63, has directed an accompanying short film which asks world leaders: “How will you keep your promise?”

The Love Actually director told the PA news agency: “I went to Ethiopia during the famine in 1986 and ever since then I have never been able to get over the sense when I wake up in the morning of how incredibly tough other people’s lives are.

“People are waking up this morning somewhere choosing whether they spend the money they have on food, their children or medicine. I feel that very personally as a father.

The United Nations open letter (United Nations/PA)

“But I also feel it as a member of an older generation and as a person with a little bit of influence, to honour the real enthusiasm we have from this younger generation – an activist generation.

“I have got a daughter who is a real activist on the subject of feminism, gender rights and mental health, which is something that is only just coming into focus.

“There are all these young, passionate people – particularly on the subject of climate change, gender and mental health – and they are saying that our generation has failed.

“I am trying to take a responsible attitude to the passion that is coming from all around me.”

The launch comes a week after UN Secretary General Antonio Guterres urged the international community to make the 2020s the “decade of action” and 2020 the “year of urgency”.

Signees want to see their leaders follow the UN’s Global Goals blueprint ahead of key moments this year such as the UN General Assembly and a landmark biodiversity conference in China.

Dame Emma Thompson
Dame Emma Thompson has also signed the letter (Ian West/PA)

Tarana Burke, founder of the Me Too movement, said: “The Global Goals are a solutions-focused plan that the world needs.

“They are as much about what is happening in the USA as in Uganda.

“They build on a vision of a world in which women and girls can live free from violence, harassment and discrimination, but we all know that is a long way off.

“That’s why we must use these goals as a tool to hold our leaders to account and to boost all our efforts.

“I’m proud to stand with climate campaigners, human rights defenders, education activists today to send a clear message to leaders that these goals are all our goals.

“We are ready – and we are watching – for action.”

Tarana Burke
Tarana Burke founded the Me Too movement (Ian West/PA)

Patrisse Cullors, co-founder of Black Lives Matter, said: “The battle for justice and equality becomes more urgent with every passing day.

“I am proud to join together with 19 other activists today, across issues, across continents and generations – to demand world leaders deliver on their promises contained in the Global Goals.

“We are doing our bit. They must do theirs.”

The open letter demands sustained innovation, financing and action over the next decade.

It highlights that at least half the global population does not have access to essential health services and that, at the current rate, it will take almost a decade to close the gender gap.

The full list of signatories can be seen at globalgoals.org