Climate negotiations tend to be dominated by debates between nations about who is causing climate change, who is most vulnerable to it and who should pay to fix it. Every country has a role to play in tackling climate change, but some – including the UK – have emitted a disproportionate amount of carbon and carry a greater responsibility to lead the way.

First, let’s look at which nations emit the most carbon today. Throughout most of modern history, the USA has been the biggest emitter. But it was overtaken by China in the early 2000s – China’s emissions have more than doubled since 2003, and now make up over a quarter of the global total. The UK, by contrast, has fallen to 18th on total emissions in recent years, partly due to its much smaller population.

The three biggest emitters – China, USA and the EU – account for 46% of all carbon emissions, despite making up only 28% of the world’s population. The EU’s emissions began to flatten in the 1970s (around the same time as China’s first began to surge), while in the USA emissions have only really levelled off in the last decade or so.

Total emissions only tell us part of the story. Once we consider emissions per person, the role of the most advanced economies in carbon emissions becomes clearer.

The USA and Australia are among the highest emitters per person in the world. China has actually overtaken the EU and UK on per capita emissions, though is still some way behind the USA on this measure. India, the world’s second most populous country, has much lower per capita emissions, though they are growing slowly.

And there is another level of nuance we need to consider. We normally measure carbon emissions where they are produced, but many countries (such as the UK) import a lot of manufactured goods from overseas. This can make carbon emissions appear artificially low. When you consider the UK’s full “consumption-based” footprint, you can see its per capita emissions are higher than China’s, because the UK imports carbon-heavy goods while China exports them.

The biggest source of emissions is electricity and heat, through the fossil fuels – coal, oil, gas that are still burnt in most power plants and homes. The other three big sources are transport (including cars as well as planes and ships), manufacturing & construction and agriculture. Finding ways to decarbonise these activities – and some other smaller emitters such as waste and land use – is vital if we are to avoid runaway climate change.

And this is something the UK has already taken a lead on. Our emissions from electricity generation have fallen by over half since 2007, a major success. It’s happened because innovation in wind and solar power, coupled with a switch away from coal to gas, have made renewable energy among the cheapest as well as the cleanest sources of power. This is an important breakthrough that the UK can help to share with the world.

However, we have made far less progress in most other areas. On transport, business emissions and home heating, we have barely reduced emissions, and need to take urgent action. It is this last area, heating our homes, that Nesta is focusing on in our mission to create a sustainable future.

This gives an idea of the scale of the challenges and responsibilities our leaders face at COP26 over the coming days. We need to end our global carbon habit, and the UK has a responsibility to play a leading role in getting there.