What is net zero and is the UK on track to achieve it?

Achieving "net zero" is the world's key target for fighting climate change, which is already having serious consequences for people and nature around the globe.

But the political consensus around the UK's net zero policies has collapsed, with opponents now branding them too difficult and expensive.

Net zero means balancing the amount of planet-warming "greenhouse" gases produced by human activities with the amount being actively removed from the atmosphere.

Effectively this means no longer adding to the total amount of these gases in the atmosphere to limit climate change.

Greenhouse gases include carbon dioxide (CO2) and methane. Their levels in the atmosphere are increasing rapidly due to human activities, including the burning of fossil fuels, chopping down of forests and farming.