Key Difference – CO2 vs CO2e
The terms CO2 and CO2e seem similar but are different terms by their definitions. However, they are related to each other because they are the major greenhouse gas components. CO2 is carbon dioxide gas. It is a colourless gas. The density of this gas is higher than the dry air. It is one of the major gaseous compounds that is released due to human activities. The term CO2e stands for carbon dioxide equivalents. It is a measure of how much global warming is given by a particular greenhouse gas as a function of the amount or concentration of carbon dioxide gas. The key difference between CO2 and CO2e is that CO2 is a gaseous compound whereas CO2e is a measure of the greenhouse effect.
What is CO2 ?
CO2 is carbon dioxide gas. It is a colourless gas with a higher density than that of dry air (about 65% higher). The carbon dioxide molecule is composed of a carbon atom covalently bonded to two oxygen atoms, and the molecule comprises a linear geometry. When it naturally occurs, carbon dioxide present in trace amount in earth’s atmosphere (0.03%).
Carbon dioxide is the most common greenhouse gas that is emitted as a result of human activities when considered based on the quantity released and the contribution to the global warming. It is the most prevalent greenhouse gas after water vapour.
Carbon dioxide is a colourless gas, and at lower concentrations, it is odourless as well. At higher concentrations, carbon dioxide has a strong acidic odour. Moreover, this compound has no liquid state at standard temperature and pressure conditions.
The major source where carbon dioxide is produced and released is from the combustion of carbon-based fuels. These fuels include hydrocarbons such as methane, ethane and petroleum oil, coal, organic materials such as wood, etc. And also, carbon dioxide gas is released from factories at higher quantities where mineral processing is done. Ex: carbon dioxide is a byproduct of iron production form hematite in blast furnaces.
Although the natural carbon dioxide content in atmosphere is very low, human activities in past few decades have increased the CO2 content rapidly. Deforestation, fuel combustion, industrialization are among the major reasons. Carbon dioxide is a greenhouse gas because it can absorb and emit IR radiation (infrared radiation) coming from the sun. this gas can capture the heat coming from the light, but the emission is multidirectional (back to the sun and also on to the earth’s surface). This case global warming.
What is CO2e ?
The term CO2e stands for carbon dioxide equivalents. It is a measure of how much global warming is given by a particular greenhouse gas as a function of the amount or concentration of carbon dioxide gas. Hence, it measures the greenhouse effect of other components taking carbon dioxide as a reference. It is also a standard unit for measuring carbon footprint. The Carbon footprint is the amount of carbon dioxide released into the atmosphere as a result of the activities of a particular individual, organization, or community.
By using carbon dioxide equivalents, the carbon footprint can be expressed in simple values that can be used for further comparisons. Hence, it is the common unit to indicate the contribution of different gases on global warming.
The quantitative expression of the greenhouse effect can be given as carbon dioxide equivalents by multiplying the amount of greenhouse gas by the global warming potential (GWP) of that gas. The global warming potential depends on the absorption of IR radiation by the gas, the location of its absorption in the spectrum (the wavelength that the gas can absorb) and the lifetime of the gas in the atmosphere.
Hence, there are few advantages of using CO2e measurements; it gives the effect of gases on global warming by simple numbers, and it allows to compare the greenhouse effects of different gases. the other ways of expressing carbon dioxide equivalents include “CO2eq”, “CO2equivalent” or “CDE”.
What is the Difference Between CO2 and CO2e ?
CO2 vs CO2e
|CO2 is carbon dioxide gas.||The term CO2e stands for carbon dioxide equivalents.|
|CO2 is a colourless gas that can be found naturally in the atmosphere in trace amounts.||CO2e is a measure of the greenhouse effect.|
|Relation to the Greenhouse Effect|
|CO2 is a greenhouse gas; It can absorb IR radiation coming from the sun and re-emit in different directions that cause global warming.||CO2e is used to measure how much impact is on global warming by a particular greenhouse gas as a function of the amount or concentration of carbon dioxide gas emitted. This is also used to express the carbon footprint.|
Summary – CO2 vs CO2e
Carbon dioxide is a major greenhouse gas that has an impact second only to water vapour. The impact of other greenhouse gases is measured quantitatively using carbon dioxide as a reference. It is given as carbon dioxide equivalents of CO2e. The difference between CO2 and CO2e is that CO2 is a gaseous compound whereas CO2e is a measure of the greenhouse effect.
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1.“Climate Science Glossary.” Skeptical Science. Available here
2.“What are CO2e and global warming potential (GWP)?” The Guardian, Guardian News and Media, 27 Apr. 2011. Available here
3.“Carbon dioxide equivalent.” Wikipedia, Wikimedia Foundation, 17 Feb. 2018. Available here
1.’Carbon-dioxide-3D-vdW’ (Public Domain) via Commons Wikimedia
2.’Nzghg gases red-7 6-07’By Mrfebruary – Own work Data Source: Ministry for the Environment (2009) New Zealand’s Greenhouse Gas Inventory 1990–2007, Ref. ME 928, April 2009, Ministry for the Environment, Wellington, New Zealand.Figure 2: Trends in greenhouse gas emissions by gas: 1990–2007., (CC BY-SA 3.0) via Commons Wikimedia