Carbon Emissions: Where are they coming from?

Over the past couple of weeks, Ive been looking at how we can build a UK Carbon Dashboard. Ive been looking at where the UKs carbon emissions actually come from, and how we can try to monitor live carbon emissions from each sector. As you might guess, this is somewhat easier for some sectors than others, but weve had some great input and the plan is starting to come together. So, what have we got so far?


Energy. When you think emissions, its probably the first thing you think of, and obviously it is a big contributor (but not the biggest), with energy supply emissions making up 27% of the UKs net carbon emissions in 2018 (provisional figures). Luckily, its actually fairly easy to estimate the emissions live - in fact, theres already a few places that do this already - theres Gridwatch, GridCarbon, ElectricityMap and others.

These work because we know the average carbon intensity for each source of electricity generation, and we can also get live data on the UKs generation mix from National Grid - they even have an API we can use to get all this data automatically.

So, all in all, its fairly straightforward.

Cars, cars, cars

The big one. In 2018, transport was the single biggest contributor, accounting for 33% of the UKs net carbon emissions. Obviously this isnt just from road vehicles, but we thought this would be a good place to start. We know we can get historic data on emissions, but for the dashboard the idea is to have live, changing data. Obviously its impossible to accurately measure the entire UKs road transport emissions at any given moment, but weve been looking at ways we can estimate pieces of the data - for example, could we show a live estimate for Leeds city centres transport emissions? Or live motorway emissions?

DEFRA have an emissions toolkit, which can calculate average emissions given traffic flow and speed data, which in principle would be useful, but the functions for working out CO2 emissions are quite outdated now. I met with Dr James Tate, from the Institute for Transport Studies at Leeds University yesterday, who has actually developed more accurate functions, and has kindly offered to share these and help out with the transport side of the project.

Of course, we need the traffic flow data first, so the next job is to look at ways of obtaining this. One idea we discussed was getting local data from the council, and getting live motorway data from Highways England. As always, wed love some help on this, and you can add any ideas or data sources to our collaborative document here.

Basically, the plan is:

  • Obtain traffic flow and speed profile data (given in 1 hour time periods)
  • Estimate the number of each type of road vehicle using Highways Englands fleet mix data from last year (this barely changes from year to year) then apply Dr Tates functions for each vehicle type to estimate the carbon emission in any given hour
  • Potentially scale the data from a set of roads to the whole city
  • Add it to our carbon dashboard!

This is just our initial plan, and its in early stages, so please let us know what you think - especially if you have any good data sources!

In terms of other transport methods, we need to find out where we can get the data, and make decisions on what we actually class as UK emissions - ie how do we deal with international flights? I would assume it will be easier to find out how many planes are in the sky right now than cars on the road, but we shall see.

I really want peoples ideas on this - data sources, methods for estimating emissions, what we should be including, tools that already exist - anything - just add it to this document.

What next?

Well start to look at getting hold of traffic flow data so we can trial our plan for estimating road transport emissions, but in the meantime theres plenty more work to do.

Were off to a solid start, but obviously energy and transport arent the only sources of carbon emissions - we havent even began to consider the others yet. If anyone has any ideas on how we can get agricultural emission data, wed love to hear them.

Thanks to everyone whos already contributed - Ill be updating the blog next week to let you know how its going, but please keep the ideas coming!