The UN’s new environment chief has called for a post-Brexit Britain to link up with the EU on environment policy, adopting key bloc climate laws and maintaining its nature directives.

In his first interview since taking office, Erik Solheim told the Guardian it was vital that supranational decisions continued for problems such as pollution and wildlife crime which crossed borders, and could not be dealt with by states acting alone.

He said: “The UK can relate to the EU’s climate decisions and be covered by them, just as Norway and Switzerland are. Norway brought its emissions into the Emissions Trading System (ETS) and adopted nearly all of the EU’s environmental law. You can coordinate closely with the EU even if you’re outside it.”

Pledges made by pro-Brexit ministers to scrap the birds and habitats directive “in the heat of the campaign” should not set the tenor of post-Brexit environmental policy, he said.

“It is very, very important to defend these regional environmental mechanisms as there is no way we can protect migratory animals like birds in just one habitat. You need global or regional agreements and I’m absolutely confident that the UK will remain committed to this, whatever happens.”

Maintaining environmental progress that the EU had driven forward would require “huge coordination in Europe, which will have to be done by the EU,” he argued.

Populist opposition to regional cooperation agreements championed by the international community has spread far beyond the UK. Many analysts see echoes of the Brexit campaign’s mobilisation of globalisation’s victims in the appeal of the US presumptive presidential nominee, Donald Trump.

Asked about Trump’s pledge to bin the Paris climate agreement, Solheim said there was a “huge danger” in politicians taking anti-scientific positions on climate change when it suited them.

“Those who want to fight against the Paris agreement do so at their own peril,” he said. “They will lose jobs and not be at cutting edge of new technologies. Those who want to fight for the old instead of embracing the new will lose.”

Trump has also welcomed the Brexit vote as a “great victory” in a binary battle between “the people” and “the elites”. But the disintegration of the EU would be a “catastrophe” for conservation efforts, and could threaten Europe’s very survival, Solheim said.

“There is no doubt that if the EU had not been created, someone would have needed to invent it. Europe cannot survive without the EU. We need decisions which are supranational, and if the EU were to completely disintegrate, that would be a catastrophe for Europe. It is not going to happen.”

The EU is thought to have the world’s largest body of environmental legislation. In the aftermath of the UK’s leave vote, figures such as the billionaire financier George Soros warned that the EU’s disorderly demise was now “practically irreversible”.

Solheim pinpointed one key lesson from the Brexit campaign: “Environmental issues need to be framed in a way that is much closer to people’s hearts and cannot be abstracted.”

“Pollution is an issue that is affecting you, your children and the planet in the here and now,” he added.

As director of the United Nations Environment Programme (Unep), Solheim will be prioritising action on pollution, protection for the world’s oceans and green fund-raising from big financial players.

A former Norwegian environment minister and socialist politician, Solheim has had a distinguished career. He also served as a diplomat who negotiated a truce in fighting between the Sri Lankan government and Tamil Tigers in 2002.

Before arriving at Unep, he spent three years as head of the Organisation for Economic Co-operation and Development’s (OECD) development assistance committee, and will bring a financial acuity to the UN’s conservation work.

One way of addressing fears of investor flight to Frankfurt and Paris diminishing London’s status as a global money hub, would be to declare it a “green financial centre,” he said.

Clear statements of commitment to EU environmental policies, such as the ETS, by the “main actors” in the Labour and Conservative parties would help to address investor uncertainty in the here and now, he said.

Like Norway, the UK could remain a member of the ETS and subscribe to virtually all of the EU’s climate and environment legislation, while keeping the ability to launch independent diplomatic demarches.

“Norway has utilised the space of not being an EU member to pursue peace initiatives in different parts of the world which would probably have been more difficult if it was in the EU,” he said. “It allows the space to take global leadership on some issues.”

Norway and the UK were “like twins” in many ways, he added.