The City of London produces more than twice as much carbon dioxide (CO2) than anywhere else in the UK, new figures show.
The City, which hosts most of the UK's financial sector and operates largely independently of the rest of the capital, produced 203 kilotonnes of CO2 per square kilometre in 2019, the highest in Britain according to the Office for National Statistics.
The area, which is the smallest local authority in Britain at little more than one square mile, has seen a dramatic drop in emissions since 2006 when it reported a high of 563kt of CO2 per square kilometre.
The 10 areas with the highest CO2 emission were all in London.
The area with the second emissions was Westminster with 77kt of CO2 in 2019, down 50% from 155kt of CO2 in 2005.
The next 11 areas with the highest CO2 emissions were also in the capital, they are: Kensington and Chelsea, Tower Hamlets, Camden, Islington, Hammersmith and Fulham, Lambeth, Hackney, Southwark, Newham, Wandsworth and Haringey.
The place with the highest emissions outside of London was just next to the capital in Slough with 21kt of CO2.
London is by far the most densely populated area of the UK and also houses many of the nations largest offices which may explain why it contributes so much to the nation's pollution.
The fact the City has more than double the second-highest emissions out of anywhere in the country may raise questions over if it can remain outside of the normal legislative structures.
London leaders have been aware of their city's pollution problems for years and have introduced various policies to reduce emissions like the Ultra Low Emissions Zone which charges polluting vehicles to drive in the area.
Mayor Sadiq Khan has made reducing emissions one of his core aims and often points to the fact the roughly 9,400 deaths a year attributed to poor air quality.
What about the rest of the UK?
CO2 admissions have dropped by 36% in the period between 2005 and 2019 but the drop varies by area.
The largest drop in percentage terms was in the North East (56%) and the least in the East of England (30%).
The most polluting areas of the UK outside of London are centred around many of the country's largest cities.
The centre of Manchester produced 17.5kt of CO2 in 2019 while the centre of Birmingham made 15.2kt.
Areas with large industrial enterprises are also fairly high on the list, like Port Talbot in Wales and Stockton-on-Tees in the North East.
Scotland had significantly lower emissions than many areas of England, with its most polluting are being Glasgow with 13.7KT of CO2.
Northern Ireland was similar with 10.4kt of CO2 produced in 2019.
Why is it so important?
Greenhouse gases in the atmosphere, such as carbon dioxide, trap heat and keep the planet warm.
But the more of these gases we have put into the atmosphere through activities such as burning fossil fuels to heat homes, drive cars and provide electricity for our lives, the more the planet warms.
Watch: Which countries release the most CO2?
These rising temperatures drive climate change, the extreme weather, rising sea levels, heatwaves, and floods that we are already seeing increase around us.
The UK has a target to reach net zero emissions by 2050 and the Government has set out its strategy for how it aims to get there.
CO2 accounted for 80% of greenhouse gas emissions in UK in 2019.
The Government published its long-awaited “net zero” strategy on Tuesday ahead of crucial UN Cop26 climate talks which the UK is hosting in Glasgow, which ministers hope will set an example to other countries on how to go green.
Cop26 will be the largest discussion on climate change since the landmark Paris agreement in 2015.
The government hopes to keep many nations committed to keeping global warming below 1.5C.
There are doubts over whether the conference will be a success with key leaders like Russia's Vladimir Putin and China's Xi Jinping saying they are not going to attend.
Most leaders that have said they will not attend have cited the pandemic as the main reason but many see it as a snub.
Watch: What is COP26?