Breakthrough in estimating fossil fuel CO2 emissions

Published by  News archive

On 22nd Apr 2022

Weybourn Atmospheric Observatory
Grant Forster

A team of scientists led by the University of East Anglia (UEA) has made a major breakthrough in detecting changes in fossil fuel carbon dioxide emissions more quickly and frequently.

In a study published today they quantified regional fossil fuel CO2 emissions reductions during the Covid-19 lockdowns of 2020-2021, using atmospheric measurements of CO2 and oxygen (O2) from the Weybourne Atmospheric Observatory, on the north Norfolk coast in the UK.

The estimate uses a new method for separating CO2 signals from land plants and fossil fuels in the atmosphere.

Previously it has not been possible to quantify changes in regional-scale fossil fuel CO2 emissions with high accuracy and in near real-time.

Existing atmospheric-based methods have largely been unsuccessful at separating fossil fuel CO2 from large natural CO2 variability, so that estimates of changes, such as those occurring in response to the lockdowns, must rely on indirect data sources, which can take months or years to compile.

The atmospheric O2-based method, published in the journal Science Advances, is in good agreement with three lower frequency UK emissions estimates produced during the pandemic by the Department for Business, Energy and Industrial Strategy, the Global Carbon Budget and Carbon Monitor, which used different methods and combinations of data, for example those based on energy usage.

Crucially, as well as being completely independent of the other estimates, this approach can be calculated much more quickly.

The researchers are also able to detect changes in emissions with higher frequency, such as daily estimates, and can clearly see two periods of reductions associated with two UK lockdown periods, separated by a period of emissions recovery when Covid restrictions were eased, during the summer of 2020.

Researchers at UEA - home of the UK’s only high-precision atmospheric O2 measurement laboratory - worked with colleagues at Wageningen University in the Netherlands and the Max Planck Institute for Biogeochemistry, Germany.

The study’s lead author, Dr Penelope Pickers, of UEA’s Centre for Ocean and Atmospheric Sciences, said: “If humans are to reduce our CO2 emissions from fossil fuels and our impact on the climate, we first need to know how much emissions are changing.

“Our study is a major achievement in atmospheric science. Several others, based solely on CO2 data, have been unsuccessful, owing to large emissions from land plants, which obscure fossil fuel CO2 signals in the atmosphere.

“Using atmospheric O2 combined with CO2 to isolate fossil fuel CO2 in the atmosphere has enabled us to detect and quantify these important signals using a ‘top-down’ approach for the first time. Our findings indicate that a network of continuous measurement sites has strong potential for providing this evaluation of fossil fuel CO2 at regional levels.”

Currently, fossil fuel CO2 emissions are officially reported with a ‘bottom-up’ approach, using accounting methods that combine emission factors with energy statistics to calculate emissions.

These are then compiled into national inventories of estimated greenhouse gas (GHG) emissions to the atmosphere from anthropogenic sources and activities, such as domestic buildings, vehicles, and industrial processes.

However, inventories can be inaccurate, especially in less developed countries, which makes it more difficult to meet climate targets.

It can also take years for the inventory assessments to be completed, and at the regional scale, or on a monthly or weekly basis, the uncertainties are much larger.

An alternative method of estimating GHG emissions is to use a ‘top-down’ approach, based on atmospheric measurements and modelling.

The UK emissions inventory is already successfully informed and supported by independent top-down assessments for some key GHGs, such as methane and nitrous oxide.

But for CO2, the most important GHG for climate change, this has never before been feasible, because of the difficulties distinguishing between CO2 emissions from fossil fuels and land plant sources in the atmosphere.

Dr Pickers said: “The time taken for inventories to be completed makes it hard to characterise changes in emissions that happen suddenly, such as the reductions associated with the Covid pandemic lockdowns.

“We need reliable fossil fuel CO2 emissions estimates quickly and at finer scales, so that we can monitor and inform climate change policies to prevent reaching 2°C of global warming.

“Our O2-based approach is cost-effective and provides high frequency information, with the potential to provide fossil fuel CO2 estimates quickly and at finer spatial scales, such as for counties, states or cities.”

The team used 10 years of high-precision, hourly measurements of atmospheric O2 and CO2 from Weybourne Atmospheric Observatory, which are supported by the UK’s National Centre for Atmospheric Science. Having long-term measurements of these climatically important gases was crucial to the success of the study.

To detect a Covid signal, they had to first remove the effects of atmospheric transport on their O2 and CO2 datasets, using a machine learning model.

They trained the machine learning model on pre-pandemic data, to estimate the fossil fuel CO2 they would have expected to observe at Weybourne if the pandemic had never occurred.

They then compared this estimate to the fossil fuel CO2 that was actually observed during 2020-2021, which revealed the relative reduction in CO2 emissions.

‘Novel quantification of regional fossil fuel CO2 reductions during COVID-19 lockdowns using atmospheric oxygen measurements’, Penelope A. Pickers et al., is published in Science Advances on Friday, April 22, 2022.

Latest News

The Norwich market.
30 Sep 2022

Brandland Event

Norwich’s prestige as a world-leading centre for brands will be celebrated in a city centre exhibition later this month.

Read more >
A young girl using a mobile phone.
30 Sep 2022

Collective effort needed to help children thrive following exposure to online risks

Helping children become more ‘digitally resilient’ needs to be a collective effort if they are to learn how to “thrive online”, according to new research led by...

Read more >
Night-time traffic in the UK.
29 Sep 2022

Slowing city traffic cut road deaths by a quarter, study shows

Restricting a city’s speed limit to 20mph reduced road deaths by almost a quarter and serious injuries by a third, according to new research involving UEA.

Read more >
An indigenous man stands in front of a camera.
29 Sep 2022

Report calls for Indigenous Peoples’ knowledge to be included in climate policy

A new report highlights how recognising Indigenous Peoples’ and local communities’ knowledge systems could do more to address climate change.

Read more >
Are you searching for something?
An indigenous man stands in front of a camera.
29 Sep 2022

Report calls for Indigenous Peoples’ knowledge to be included in climate policy

A new report highlights how recognising Indigenous Peoples’ and local communities’ knowledge systems could do more to address climate change.

Read more >
A Japanese flame pot.
29 Sep 2022

‘Circles of Stone’ links astonishing prehistoric parallels of Japan and Britain

Read more >
An Ethiopian drought.
28 Sep 2022

Rising global temperatures point to widespread drought

Worsening droughts caused by rising global temperatures pose significant risks around the world – according to new research from UEA. 

Read more >
Microscope view of the monkeypox virus.
23 Sep 2022

Monkeypox outbreak highlights need for One Health approach to prevent future zoonotic diseases

The outbreak of monkeypox is a warning for the adoption of a preventative, One Health, approach, accoding to research from UEA.

Read more >
A man in a consultation with a medical professional.
22 Sep 2022

UEA breakthrough reveals how prostate cancer may begin

Researchers at the University of East Anglia have made an important discovery about how prostate cancer may start to develop.

Read more >
23 Sep 2022

UEA teacher education partnership celebrates good Ofsted outcome

The University of East Anglia (UEA) Initial Teacher Education (ITE) partnership has received a ‘good’ rating across the board, following an Ofsted inspection of...

Read more >
​​​​​​​Baran Guccuk
01 Aug 2022

2022 Clifford Chance Policy Competition Law Excellence Prize

Congratulations to ​​​​​​​Baran Guccuk, Law School LLB Graduate, who won this year’s Clifford Chance/CCP Competition Law Excellence Prize

Read more >