<p>Rather than using the GWP as a ratio, they are expressing the GWP as compared to a release of <a href="https://en.wikipedia.org/wiki/Carbon_dioxide_equivalent" rel="nofollow">$\ce{CO2}$ with equivalent radiative effects</a>.  To use their numbers use the mass they give you and a GWP ratio of 1 for that mass (as if it were carbon dioxide).  From what I've seen for chemical industry sales and marketing literature it is fairly common that they express GWP this way in units of "$\ce{CO2}$ equivalent".</p>

<p>In other words, they are saying whatever their product is made of and its production methods have the same radiative forcing as $x$ kg of $\ce{CO2}$.</p>

CC BY-SA 3.0
2015-12-16T03:28:08.917Z
2015-12-16T17:19:24.073Z
2015-12-16T17:19:24.073Z
casey
<p>I was under the impression GWP (global-warming potential) is the measure of a gas' impact on global warming, in comparison with CO2. </p>

<p>E.g. methane has a GWP of 86 over 20 years - <a href="https://en.wikipedia.org/wiki/Global-warming_potential" rel="nofollow">Wikipedia</a></p>

<p>Comparing paper and ceramic cups for GWP, <a href="https://www.tcd.ie/GreenPages/documents/refiller_cup_comparison.pdf" rel="nofollow">this article</a> (page 24) shows GWP in kilograms. Does this make sense to show GWP in kg? Can anyone explain why?</p>

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2015-12-16T08:21:24.367Z
Question was cross-posted [here](http://sustainability.stackexchange.com/q/4926/99)
THelper
<climate><climate-change><co2><gas><methane>
What is meant by Global-warming Potential (GWP)?
Sam Perry
# What is meant by Global-warming Potential (GWP)?

(Asked by: username_0 on 2015-12-16)

I was under the impression GWP (global-warming potential) is the measure of a gas' impact on global warming, in comparison with CO2.

E.g. methane has a GWP of 86 over 20 years - [Wikipedia](https://en.wikipedia.org/wiki/Global-warming_potential)

Comparing paper and ceramic cups for GWP, [this article](https://www.tcd.ie/GreenPages/documents/refiller_cup_comparison.pdf) (page 24) shows GWP in kilograms. Does this make sense to show GWP in kg? Can anyone explain why?

**Tags:** climate, climate-change, co2, gas, methane

> **Comments:**
> **username_1**: Question was cross-posted [here](http://sustainability.stackexchange.com/q/4926/99)  

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## 1 answers

### Answer by username_2 on 2015-12-16. Score: 5 | Accepted answer

Rather than using the GWP as a ratio, they are expressing the GWP as compared to a release of [$\ce{CO2}$ with equivalent radiative effects](https://en.wikipedia.org/wiki/Carbon_dioxide_equivalent). To use their numbers use the mass they give you and a GWP ratio of 1 for that mass (as if it were carbon dioxide). From what I've seen for chemical industry sales and marketing literature it is fairly common that they express GWP this way in units of "$\ce{CO2}$ equivalent".

In other words, they are saying whatever their product is made of and its production methods have the same radiative forcing as $x$ kg of $\ce{CO2}$.


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