Analysis of Air Emissions around the COVID-19 Pandemic

Date: 10/12/2022

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Introduction

According to Met Office, the main cause of climate change is burning fossil fuels such as oil, gas, and coal. When burnt, fossil fuels release carbon dioxide (CO2) into the air, causing the planet to heat up. This statement can be supported by NASA, who claims that carbon dioxide in the atmosphere warms the planet, causing climate change. Human activities have raised the atmosphere’s carbon dioxide content by 50% in less than 200 years.
 
For this project, the aim is to find data relating to global emissions of CO2 and other polluting gasses and to analyze the changes in these emissions before and after the COVID-19 pandemic. Due to the pandemic, many countries implemented measures to allow workers to perform their jobs safely, mainly by allowing workers to work from home. The idea we are working with is that this change in working would likely have some impact of the amount of CO2 emissions from countries that implemented this strategy due to the increase in demand for electricity with more people working remotely. Additionally, it may be the case that with less people travelling, the emissions from transportation may have decreased which would be another protentional point to investigate. The overall idea is that we want to understand whether the pandemic had a significant impact on emission levels. We believe that investigating these results could motivate to look at some sectors and countries in more details in order to make some changes and ,hopefully, slow down the climate change.
 
We shall take data relating to global emissions and break it down by country. By combining this data with other data about the countries, such as energy demand, we can see how and why emissions may have changed for these countries. We will also break down the specific sources of emissions as there are several areas from which they may be emitted, from transportation to general industrial pollution. All of this data will be required in order to determine exactly where the emissions are coming from and whether it is related to an increase in energy demand or some other unseen factor.

Data Sources

All data was found on ourworldindata.org website. One of the datasets contains the information about CO2 emissions, other greenhouse emissions, population, energy consumption and many other calculated values for every big country for more than 100 years. It will be discussed in more details later. Ourworldindata claims to work with a lot of top research and media companies as well as with top Teaching institutions such as Harvard, Stanford, and Oxford. So, it can be considered as a reliable source of data. Together with this dataset there is a codebook file. Using this codebook, user can check the definition and source of any column from the CO2 dataset. Both datasets can be found on ourworldindata github page.
 
For this project we also use emission by sector dataset which is also available on ourworldindata website. It contains information about the CO2 emission distribution by sector for some major countries for the past 30 years. It is available from their website here. Using this dataset, it will be possible to see which sectors emit most of the CO2 in countries and look at this distribution in 30 years range. Even though all of these datasets contain useful information there are a lot of missing values and useless, for this project, variables.

NOTE:

This webpage does not include investigating and cleaning datasets. This process, together with required datasets, can be found on my github page. Instead, only analysis and visualization parts are represented.

Exploring patterns in CO2 emissions for the past 30 years

First of all, it is important to state why these numbers are necessary at all. It is a known fact that CO2 emissions are the main cause of Greenhouse effect in the atmosphere and steadily increasing temperature. Climate NASA claim that the global temperature anomaly (the departure, positive or negative, of a temperature from a base temperature) has doubled for the past 30 years. According to TheWorldCounts, further increase in temperature will cause the ice caps and glaciers to melt, causing sea levels to rise and inundating coastal cities – where most of human civilization is located. Warmer oceans will cause more severe weather disturbances such as intense hurricanes and tsunamis, further causing havoc to our cities. The absence of our polar caps and glaciers will contribute to further warming since these ice caps help reflect the sun’s heat back into space. Without them, the planet will absorb the sun’s heat more.
 
Figure below represents the annual global emissions of CO2 in billion tons.
It can be seen that since 1991 the global emissions are steadily increasing and by 2021 the amount increased by more than 50%. It can be noticed that there two drops in the emissions: in 2009 and 2020. According to The Guardian, global emissions of carbon dioxide dropped by 1.3% in 2009 compared with the previous year, largely due to the effects of the economic crisis and an overall fall in GDP. The drop in 2020 can be explained by COVID-19 pandemic and global quarantine. This project will try to investigate this drop in more details.
 
Before exploring CO2 emissions it is worth mentioning that carbon dioxide is not the only greenhouse gas that human activities emit. Methane and Nitrous Oxide are both greenhouse gases that are emitted by human activities. Below is the graph of annual global emissions of these two chemicals for the same time period.
Both Methane and Nitrous Oxide are more dangerous than Carbon dioxide. However, it can be seen that the amount that is emitted and the growth rate are significantly lower than for CO2. Moreover, CH4 and N2O lifetime in the atmosphere is also much lower. That is why for this project it was decided to mainly focus on CO2 emissions. However, it does not mean that Methane and Nitrous Oxide are insignificant and can be ignored. It can be noticed in the Graph above that the amount of emissions of these two gases increase steadily every year and as they are more dangerous it could cause much more serious problems if nothing is done to prevent it.

Top 10 countries by CO2 emissions

To investigate the most “problematic” areas we can look at top 10 countries by CO2 emissions. As one of the objective is to look at the influence of COVID-19 pandemic there are two bar charts representing top countries in 2019 (pre-covid) and 2020 (covid year).
It can be seen that China is World’s leader in emitting CO2 with approximately double the amount of 2nd place, USA. Obviously, this is very concerning for Chinese population but what could be even more concerning is that 3 out of 5 countries in the top 5 are in Asian region. Even though COVID-19 decreased the amount of CO2 for almost every country, India, Japan and China are consistently in top 5. This could potentially be serious issue for the people living in Asia. It can also be noticed that despite the pandemic all of the top 10 countries in 2019 graph stayed on the list in 2020.

Another important index is CO2 emissions per capita. Below there are two graphs showing top countries by this metric in 2019 (pre-covid) and 2020 (covid year).
In CO2 per capita emissions Qatar is the leader in both pre-covid and covid years. This index is important because it means that in this region people are most likely to actually feel the influence of Carbon Dioxide emissions on air quality and temperature. All these top emitters graphs helps us to choose countries for more detailed analysis.  
 
During the pandemic there were a lot of talks about how much more electricity people use due to lockdowns and increased amount of people working and studying from home. Some entities even encouraged people to use less electronic devices. As the main source of electricity is burning fossil fuels like coal and gas, which is also the main emitter of CO2, it is important to look at the patterns of energy consumptions as well.

It can be noticed that there is a significant drop in energy consumption during COVID-19 lockdown. Therefore, it is very unlikely that people staying at home and consuming more electricity than usual do not cause as much emissions as other sectors. Otherwise, the drop would be much less significant. More plausible explanation could be that a lot of factories and companies had to halt their operations due to the pandemic. However, the problem of increasing energy consumption over the whole year range is still concerning.

China

To find out what could be the potential causes of the patterns discovered in the previous objective some
countries’ emissions could be looked at with more detailed dataset.

 

The first country to explore is China. It consistently has the highest amount of Carbon Dioxide produced.

It can be seen that China do not follow global patter and do not have any drops in CO2 emissions and energy consumption during COVID-19 period. China has the highest population and being the origin country of the virus implemented quarantine the earliest. So, it was expected that due to less transportation there will be some drop in the CO2 as was shown in the global emissions plot. To explore this contradiction, we can look at CO2 emission by sector in China.

It can be seen that the two most emitting sectors in China are “Electricity and Heat” (5,5 billion tons) and “Manufacturing and Construction” (2,5 billion tons). Combined they produce more than half of the total emissions. Transport sector (which is the most affected by quarantine) is on the 3rd place with approximately 1 billion tones. On the 4th place, not far from “Transportation”, is “Industrial Processes” sector. Therefore, one probable reason for the continued increase in China’s air emissions is that Chinese manufacturers and power plants likely did not significantly decrease their production during COVID-19. As China is the most polluting country, its two top sectors should be investigated more. However, this is out of the scope of this project and can be one of the topics for Future work.

United States

The next country to look at is the USA. Even though it produces half of the CO2 that China emits, it still consistently takes 2nd place in the global rating.

It can be noticed that after 2006 annual CO2 emissions in the USA started to decrease. However, it is still high enough to place America on the second place out of all countries. Therefore, there are problems in the USA air quality that need to be addressed. Also, in contrast to China graphs significant drop can be noticed in both CO2 emissions and energy consumption during the pandemic. To investigate the potential reasons we can take a look at the emission distribution by sector.

It can be seen that the ‘Electricity and Heat’ (1.76 billion tons) and ‘Transportation’ (1.5 billion tones) sectors are the most polluting in the USA, and during the pandemic, they both experienced significant drops. ‘Electricity and Heat’ emissions decreased by approximately 10.3%, while ‘Transportation’ reduced by 14.2%. According to this Wikipedia page, United States are in the second place by the total number of cars (305 million) with China in the first place (417 million). Interestingly, the difference between the USA and third place, Brazil, is much higher. In Brazil there are approximately 83 million cars which is almost 4 times lower than in the US. Therefore, when quarantine was enforced in many states in 2020, it was expected to see such a significant drop in Transportation emissions. However, contrary to many beliefs, energy consumption also experienced a significant decrease during this period. This can be observed in the USA energy consumption chart and the distribution graph, which shows that Electricity and Heat emissions decreased during quarantine. One possible explanation for this is that companies and other commercial establishments, such as shops and malls, had to halt their in-person operations. As a result, there might have been a reduction in product manufacturing, resulting in decreased energy consumption by factories and other production facilities.

Germany

The next country under analysis is Germany, selected because it is one of the few nations in the top 10 list of CO2 emitters that experienced a decrease in rank during COVID-19.

It can be seen that CO2 emissions have been consistently decreasing throughout the given period, in contrast to the patterns observed in the USA and China. This trend is also reflected in the energy consumption graph. To explore this pattern and the decline observed during the pandemic, a sector-wise distribution analysis is warranted.

The most emitting sector remains “Electricity and heat,” accounting for 0.225 billion tons, followed by “Transportation” in the second position with 0.14 billion tons. Notably, the distribution mirrors that of the USA, with a similar decline observed during the 2020 pandemic. However, when examining CO2 emissions and energy consumption over the past 30 years, Germany displays a more consistent decrease. This trend could be attributed to stricter emission policies for manufacturers within the European Union and the Union’s proactive shift towards greener energy production compared to other regions. Overall, it can be seen that COVID positively impacted air emissions in Germany and quarantine policies did not have an effect on higher electricity consumption. 

Qatar

The final country under investigation is Qatar, selected due to its consistent ranking in the first place for emissions per capita.

Looking at the figures above it is evident that Qatar exhibits similar patterns to China, with continuous increases in both CO2 emissions and energy consumption. However, in contrast to the Chinese data, a noticeable drop due to COVID-19 is observed here. To gain deeper insights, further analysis of Qatar’s emission distribution is necessary.

The data reveals that once again, “Electricity and heat” stands as the most polluting sector in Qatar, accounting for 55 million tons, followed by “Manufacturing and construction” at 17 million tons and “Transport” at 12 million tons. This distribution mirrors findings from the analysis in China. However, unlike in the USA and Germany where a significant overall drop in CO2 emissions and energy consumption was also observed during the pandemic, no noticeable decrease is evident in any sector in Qatar. Therefore, drawing meaningful conclusions for Qatar based on this data is challenging. A more detailed dataset would be beneficial in identifying the potential cause behind this lack of decline.

Conclusion

Achievements


As anticipated, CO2 emissions have steadily increased over time. However, a noticeable global decline in emissions and energy usage occurred around the 2020 mark, possibly attributed to the pandemic’s influence on work patterns. Another factor could be the potential inaccuracies in data collection and analysis by governing bodies due to the impact of COVID-19. A striking correlation between CO2 emissions and energy consumption is evident, indicating that a significant portion of air pollution stems from energy generation.

 

However, addressing the issue isn’t as straightforward as focusing solely on energy production. Transitioning to energy sources like nuclear plants instead of thermal ones could be beneficial, although it won’t entirely solve the global problem. For instance, in the USA, it was found that energy and transportation contribute nearly equally to CO2 emissions. Surprisingly, China, despite being the country of origin of the virus and implementing quarantine measures early, did not witness drops in emissions and energy consumption, unlike most other analyzed countries.

 

Meanwhile, Germany shows promising progress in reducing CO2 emissions, whereas Qatar, similar to China, exhibits an opposing trend. Notably, Qatar displays a unique pattern among the analyzed countries; despite a general drop in CO2 pollution and energy consumption in 2020, none of its sectors experienced reduced emissions. Consequently, to combat global warming and climate change effectively, it is imperative to conduct in-depth investigations into the sectors of all countries. Therefore, to prevent global warming and climate change all countries and their sectors should be investigated in more details.

 


Limitations


Many air pollution datasets available on the Internet are either restricted behind paywalls, incomplete, or contain numerous missing values. Finding a comprehensive CO2 dataset with all the necessary information proves to be challenging. In this project, a substantial amount of data had missing values, requiring extensive filtering to obtain the essential information.

 


Future Work


One prospective avenue for future research involves conducting detailed investigations into individual countries. Extending this analytical approach to specific regions and cities within each nation could uncover localized factors contributing to emissions. Furthermore, exploring the impact of changes in commuting patterns during the COVID-19 period on global CO2 emissions provides another intriguing dimension for analysis. This can be achieved by sourcing additional data on countries, specifically focusing on travel methods employed and the emissions generated by various modes of transport.