What is the conversion of ppm co2 and ppmvCO2e

[Richardlevicki]

Hi all
I am a bit of a generalist doing some work on climate change at a policy level, can someone help me out on this.

I am reading a publication and unusually he is quoting ppmc CO2e to describe tipping points.

No I know we are currently at 378ppm and he is saying that current greenhouse gas concentrations re at 430ppmv CO2e, I want to convert this back to CO2 ppm as I am very up to date with the link for this and budgets.

is it simple iee ppm 1ppm CO2 = ?? ppmv CO2e.

Thanks for any help.
Let me know if its a silly question and you think I should read something to work it our myself.
Ta
Rick

 

[MortenA]

I don't know for sure but i believe that CO2e=CO2 equivalent. This is because there are more greenhouse gasses than co2 - e.g. methane thats 21 times as powerful as co2.

ppmv=ppm volume.

So 1ppm co2 should the be equal to 1 ppmv co2e

Best regards

Morten

 

[Richardlevicki]

Hi thanks for that so according to that 430ppmv co2e should be equal to 430 ppm co2, which is where I got confused as the paper states that we are currently at 430ppmc co2e, and I understand that we are currently at 388.15 ppm co2,

http://co2now.org/

.
The paper is written by a very prominents scientist so that is where I just am at a loss???? Any answers would be really appreciated.
have I missed something obvious??
Thanks a lot

 

[25362]

May be the explanation given in

http://en.wikipedia.org/wiki/Carbon_dioxide_equivalent

is satisfactory.

 

[dcasto]

What the author is saying is that there are 42 ppm of other than CO2 in the air with their related adjustment factors. If it was all methan, that would be about 42/21 or 2 ppm methane in the air.

 

[maddocks]

The point being is that "greenhouse gases" are often quantified in terms of CO2 equivalent so that we (and the general public) can easily understand the relative effects of differing gasses. In CO2, ppm = ppm(e)