It is available online at http://www.sciencedirect.com/science/article/pii/S0921818113000891 (actually, it has been for a while, but I haven’t had much time for blogging lately!). For those of you who have already read this blog post, or the one at RealClimate by Rasmus, the contents should not be much of a shock. Sadly, the article is pay-walled, but if you don’t have university access contact me and I can see about getting you a copy. The code for the paper is available here.
Interestingly, I see that Mark Richardson of the University of Reading also has a comment on the Humlum et al. paper appearing online at Global and Planetary Change as well.
Troy's Scratchpad 
Hi Troy,
Congratulations on your paper, I think our comments complement each other nicely as you make it very clear that the Humlum et al approach doesn’t lead to their final conclusion, but I modify it and go off in a different direction to work out the conclusion from the data.
Comment by MarkR — May 16, 2013 @ 9:24 am
Thanks Mark, congrats to you as well. I agree that the comments do go off in different directions, and complement each other…in particular, I like the explicit quantification of the contributions of emissions to the CO2 rise.
Comment by troyca — May 20, 2013 @ 7:49 am
I would like to get a copy of your paper, if possible.
Comment by TedH — July 3, 2013 @ 8:55 am
Hi Ted,
Just sent a copy to your e-mail!
Comment by troyca — July 4, 2013 @ 10:34 am