Difference Between CO2 and CO2e

Key Difference – CO2 vs CO2e
 

The terms CO₂ and CO_2e 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 CO_2e 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 CO_2e is that CO₂ is a gaseous compound whereas CO_2e is a measure of the greenhouse effect.

CONTENTS

1. Overview and Key Difference
2. What is CO2
3. What is CO2e
4. Side by Side Comparison – CO2 vs CO2e in Tabular Form
5. Summary

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 CO_2e ?

The term CO_2e 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 CO_2e 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 “CO_2eq”, “CO₂equivalent” or “CDE”.

What is the Difference Between CO₂ and CO_2e ?

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 CO_2e. The difference between CO₂ and CO_2e is that CO₂ is a gaseous compound whereas CO_2e is a measure of the greenhouse effect.

Download the PDF of CO2 vs CO2e

You can download the PDF version of this article and use it for offline purposes as per citation note. Please download the PDF version here: Difference Between CO2 and CO2e

Reference:

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  

Image Courtesy:

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