The planet's unfolding environmental crisis [is] another, even deeper emergency.
The recovery from the coronavirus pandemic must put the world on track to a greener future, it has been urged, as online events mark Earth Day.
United Nations secretary-general Antonio Guterres has said the recovery from the pandemic must be turned into a real opportunity to do things right for the future.
While the impact of Covid-19 was both "immediate and dreadful" and countries must work together to save lives and lessen the consequences of the pandemic, he said there was "another, even deeper emergency - the planet's unfolding environmental crisis".
"Biodiversity is in steep decline. Climate disruption is approaching a point of no return. We must act decisively to protect our planet from both the coronavirus and existential threat of of climate disruption."
He has called for the huge amounts of money that will be spent on recovery to deliver new jobs and businesses through a clean, green transition.
Where taxpayers' money is spent rescuing businesses it should be tied to achieving green jobs and sustainable growth, he said, and should flow to sustainable sectors - suggesting he does not want countries to bail out the struggling oil industry.
Fuel subsidies must end and polluters must start paying for their pollution, he warns, adding the financial system and all areas of public policy making and infrastructure must factor in climate risks and opportunities.
A green recovery from the pandemic has been backed by the Global Climate and Health Alliance (GCHA) which includes the UK Health Alliance on Climate Change, whose members include major medical organisations and associations.
Jeni Miller, GCHA executive director, said: "We won't get another shot at this: only a global green recovery can sustain a safe and healthy future for all.
"Our health is a truly global issue: we must choose a sustainable path for our planet, to prevent further crises and protect lives."
In the UK the Green Party has said that a "green new deal" has to be central to any post-coronavirus recovery package.
The party wants to see investment in making all homes warmer and more energy efficient, a revolution in the country's transport system and a rapid roll out of renewable energy across the country, which would create hundreds of thousands of low carbon jobs.
Green Party co-leader Jonathan Bartley said the government must not fall back on its business as usual approach to deal with the economic crisis facing the country when it leaves lockdown.
"We can direct emergency economic support so that it powers a move to a sustainable, secure economy and make sure, once we come out of this emergency period, we will have an economy and a society that is more able to withstand future shocks and tackle the climate crisis," he urged.
In the face of the coronavirus, the Earth Day Network is running a digital event including video messages from Pope Francis, Al Gore, Elizabeth Warren, Zac Efron, Roger Waters, Josh Lucas and Dave Matthews.
Elsewhere on Earth Day:
- Surfers Against Sewage is launching a new digital 'beach clean' campaign, #ReturnToOffender, urging the public to document branded plastic pollution during their permitted daily walks and upload them on social media to challenge companies to tackle the plastic problem.
- The Birdlife International partnership of conservation groups is calling for the UN to declare a healthy natural environment a fundamental human right, adding an Article 31 to the Universal Declaration of Human Rights on the issue.
- A campaign backed by Extinction Rebellion, 350.org and Ethical Consumer magazine, is being launched urging consumers to take action to protect the planet, and move their money and energy away from fossil fuels and switch to supporting sustainable banks and energy providers.
- Tia Nelson, daughter of Earth Day founder, the late US senator Gaylord Nelson, has said her father would have been deeply concerned by climate scepticism among politicians.
In a conversation with Steven Day, co-founder of 100% renewable energy supplier Pure Planet, she also said that in democracies, if people weren't engaged, informed voters "electing people who are prioritising this issue then you are not doing your part".
Emily Beament is the PA environment correspondent.