UNIVERSITY OF EAST ANGLIA
A team of scientists led by the University of East Anglia (UEA) has made a major breakthrough in detecting changes in carbon dioxide emissions from fossil fuels more quickly and frequently. .
In a study published today, they quantified the reduction in CO2 emissions from fossil fuels in the region during the 2020-2021 Covid-19 shutdown, using CO2 and oxygen measurements. (O2) in the atmosphere from the Weybourne Atmospheric Observatory, on the north coast of Norfolk, UK.
Estimation uses a novel method to separate CO2 signals from terrestrial plants and atmospheric fossil fuels. Previously, it was not possible to quantify changes in regional-scale fossil fuel CO2 emissions with high accuracy and near real time.
Existing atmosphere-based methods have largely failed to separate fossil fuel CO2 from large natural CO2 variations, hence estimates of changes, such as those occurring out in response to an outage, must rely on indirect data sources, which can take months or years to compile.
Method based on atmospheric O2, published in the journal Scientific advance, in good agreement with the three UK lower frequency emissions estimates generated during the pandemic by the Department for Business, Energy and Industrial Strategy, the Global Carbon Budget and Carbon Monitoring, used different methods and data combinations, for example those based on energy use.
Importantly, as well as being completely independent of other estimates, this approach can be computed much faster.
The researchers were also able to detect changes in emissions with a higher frequency, such as daily estimates, and were able to clearly see two periods of reductions related to the two phases of the Kingdom’s lockdown. Britain, separated by the period of emissions recovery when Covid restrictions are eased, during the summer. of 2020.
Researchers at UEA – home to 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 Biochemistry, Virtue.
Lead author of the study, Dr Penelope Pickers, of the UEA’s Center for Ocean and Atmospheric Sciences, said: “If humans want to reduce CO2 emissions from fossil fuels and our impact on climate, we first need to know how emissions are changing.
“Our study is a major achievement in atmospheric science. Several other companies, based solely on CO2 data, have been unsuccessful, due to large emissions from land-based plants, which obscure the CO2 signals from fossil fuels in the atmosphere.
“Using atmospheric O2 in conjunction with CO2 to sequester CO2 from fossil fuels in the atmosphere has allowed us to detect and quantify these important signals for the first time with a ‘top-down’ approach. down’. Our findings indicate that a network of continuous measurement sites has strong potential to provide this assessment of fossil fuel CO2 at the regional level. ”
Currently, CO2 emissions from fossil fuels are officially reported with a ‘bottom-up’ approach, which uses a computational approach that combines emission factors with energy statistics to calculate emissions. waste.
They are then aggregated into national inventories of estimated greenhouse gas (GHG) emissions into the atmosphere from anthropogenic sources and activities, such as domestic buildings, vehicles and industrial processes.
However, inventories can be imprecise, especially in less developed countries, which makes meeting climate targets more difficult.
It can also take years to complete an inventory assessment, and at a regional, monthly or weekly scale, the uncertainty is much greater.
An alternative method for estimating GHG emissions is to use a ‘top-down’ approach, which is based on measurements and atmospheric models.
The UK emissions inventory has been successfully communicated and supported by independent top-down assessments of several key GHGs, such as methane and nitrous oxide.
But for CO2, the most important greenhouse gas for climate change, this has never been possible before, due to the difficulty of distinguishing between CO2 emissions from fossil fuels and terrestrial plant sources in the future. ozone.
“The time it takes to complete the inventory makes it difficult to describe changes in emissions that occur suddenly, such as the reductions associated with Covid-19 pandemic shutdowns,” said Dr. .
“We need reliable fossil fuel CO2 estimates quickly and at a better scale, so that we can monitor and inform climate change policies to prevent global warming reaches 2°C.
“Our O2-based approach is cost-effective and provides high-frequency information, with the potential to provide fossil fuel CO2 estimates quickly and at better spatial scales. , such as for counties, states, or cities.”
The team used 10 years of highly accurate, hourly measurements of atmospheric O2 and CO2 from the Weybourne Atmospheric Observatory, supported by the UK’s National Center for Atmospheric Science. Having long-term measurements of these climate-critical gases is critical 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 a machine learning model based on pre-pandemic data, to estimate the amount of CO2 from fossil fuels they expected to observe in Weybourne if a pandemic had never occurred.
They then compared this estimate with the amount of CO2 in fossil fuels actually observed between 2020-2021, which shows a relative reduction in CO2 emissions.
‘A novel quantification of regional fossil fuel CO2 reductions during COVID-19 lockdowns using atmospheric oxygen measurement,’ Penelope A. Pickers et al., published in Scientific advance on Friday, April 22, 2022.
JOURNEYS
Scientific advance
RESEARCH METHODS
Data analysis / statistics
ARTICLE TITLE
Novel quantification of regional fossil fuel CO2 reductions during COVID-19 lockdown using atmospheric oxygen measurements
ARTICLE PUBLICATION DATE
April 22, 2022
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