This forum is shutting down! Please post new discussions at

annual rate of change in the price of carbon

Hi all!
I'm trying to evaluate "annual rate of change in the price of carbon" in my carbon model. I understand that the value must be negative if i want to "suggests that the societal value of carbon sequestered in the future is greater than the value of carbon sequestered now"  but the model not allow the value '-' (negative). How can i fix it?



  • This is a use case that we were not initially anticipating, but could make sense. Our entire team is preparing for our annual Natural Capital Symposium next week, so to relax this constraint in the model and push a developmental build could take a bit depending on availability. We will let you know when this is addressed. Thanks for bringing this to our attention!
  • RichRich Administrator, NatCap Staff
    Hi Mic27, we're in the middle of refactoring the terrestrial carbon model and we've fixed the issue that was preventing you from using a negative discount rate.  This isn't in the official release yet, but if you'd like to use it you can try this development build:

    Note this update also simplifies the model where we've removed the harvested wood products option as well as the uncertainty analysis.  Let me know if I can help!

  • hi Rich 

    I downloaded this version but continue with the same error, you can not enter negative values in the discount rate of the carbon price. Is there another solution?
  • RichRich Administrator, NatCap Staff
    Hi, I just ran the posted version of this model on my end and was able to enter and use negative discount rates.  Can you post a screenshot of your error or your log if you got that far?
  • hi here you have the error
    797 x 887 - 54K
  • In addition This is an error that appears when you tried to install the InVEST package
    658 x 510 - 137K
  • RichRich Administrator, NatCap Staff
    Hi Diego!  Looks like your first screenshot is of InVEST 3.3.1 (you can see the version near the top of the window).  Offhand I'd guess that you installed multiple versions of InVEST and are just launching the wrong version from the start menu; that can be confusing, I've done it myself many times.  To address this, you can either be sure you launch the most recent version (I'd suggest 3.3.2 or just be careful to launch the 3.3.1post28 that you downloaded above.  You could also uninstall all the old versions of InVEST on your machine.

    The second error you're getting is an issue with downloading the sample data during the install.  That won't affect the core installation of InVEST but you won't get the base carbon sample data along with the installation.  Not sure why that might have happened, but it could if your Internet connection timed out during the install.  If you *really* want that carbon sample data you can download it here:

    Hopefully that addresses your issue, if not post and again and we'll work from there!

  • Hi Rich !!. I deleted all versions of invest and installed them again but I still have the same problem.
    Version 3.3.2 reports the same error as you can see in the attached photo. In the same way when running version 3.3.1post28 also has the same error.
    I do not understand what the error might be.
    1920 x 1080 - 1M
  • ..
    1335 x 839 - 498K
  • RichRich Administrator, NatCap Staff
    Ahhh I see it.  I'm sorry, but I had a cognitive blindness where I was thinking and seeing thinking "negative discount rate", not negative price increase rate.  Yes, I can duplicate that issue on my end.  I just pushed a patch and am building a binary that you should be able to use shortly.

    More soon.

    p.s. Are you running the model with a positive discount rate and a negative price increase rate?
  • RichRich Administrator, NatCap Staff
    Hi Diego, 

    Sorry for the runaround, but here's a build that'll allow for a negative ROC for carbon price:
  • Hi Rich

    Yes, I am using a positive discount rate and a negative  price increase rate!!

    Thanks for your help  
Sign In or Register to comment.