Key international climate talks due to take place in November were last night postponed until next year.
The Cop26 meeting was set to take place at Glasgow's Scottish Events Campus - which is being turned into a temporary Covid-19 field hospital - from November 9 to 20.
But an announcement from the UN's climate body, the UNFCCC, said the summit would be pushed back to 2021 in light of the pandemic.
UN climate chief Patricia Espinosa said: "Covid-19 is the most urgent threat facing humanity today, but we cannot forget that climate change is the biggest threat facing humanity over the long term.
"Soon, economies will restart. This is a chance for nations to recover better, to include the most vulnerable in those plans, and a chance to shape the 21st century economy in ways that are clean, green, healthy, just, safe and more resilient."
A mid-year UN climate meeting scheduled for June in Bonn, which would have laid groundwork for the November talks, has been delayed to October.
Cop26 is the most important round of talks since the global Paris Agreement to tackle climate change was secured in 2015.
This year marks the date by which countries are expected to come forward with stronger emissions cuts to meet the goals of the deal.
Plans submitted so far put the world on a pathway toward more than 3C of warming, though the Paris Agreement commits countries to curb temperatures to 1.5C or 2C above pre-industrial levels to avoid the worst impacts of climate change.
But with countries around the world grappling with coronavirus, an "ambitious, inclusive" meeting in November was no longer possible, and rescheduling would allow countries to focus on climate and allow more time for preparations, the UN said.
Climate campaigners said the delay to Cop26 was sensible and unavoidable, but warned the response to Covid-19 should not undermine efforts to address the climate crisis.
Meanwhile, a 'substantial' recovery of life in the oceans could be achieved by 2050 if major threats such as climate change are dealt with, a study has said.
The oceans are important sources of food, water and clean energy and key for tackling global warming as they store heat and carbon, but many marine species, habitats and ecosystems have suffered catastrophic declines.
Climate change, hitting areas such as coral reefs, is further undermining the oceans' productivity and rich wildlife, researchers writing in the journal 'Nature' warn.
But substantially rebuilding marine life, so populations rebound by 50-90pc, within a human generation is largely achievable if action including tackling climate change and restoring habitats happens on a large scale.
The scientists said the focus should be on rebuilding depleted wildlife populations and ecosystems, not simply on conserving what remains.