Context : The use of hydrodynamical simulations , the selection of atomic data , and the computation of deviations from local thermodynamical equilibrium for the analysis of the solar spectra have implied a downward revision of the solar metallicity .
We are in the process of using the latest simulations computed with the CO5BOLD code to reassess the solar chemical composition .
Our previous analyses of the key elements oxygen and nitrogen have not confirmed any extreme downward revision of Z .

Aims : We determine the solar photospheric carbon abundance by using a radiation-hydrodynamical CO5BOLD model , and compute the departures from local thermodynamical equilibrium by using the Kiel code .

Methods : We measure equivalent widths of atomic C i lines on high resolution , high signal-to-noise ratio solar atlases of disc-centre intensity and integrated disc flux .
These equivalent widths are analysed with the use of our latest solar 3D hydrodynamical simulation computed with CO5BOLD .
Deviations from local thermodynamic equilibrium are computed in 1D with the Kiel code , using the average temperature structure of the hydrodynamical simulation as a background model .

Results : Our recommended value for the solar carbon abundance , relies on 98 independent measurements of observed lines and is A ( C ) = 8.50 \pm 0.06 , the quoted error is the sum of statistical and systematic error .
Combined with our recent results for the solar oxygen and nitrogen abundances this implies a solar metallicity of Z = 0.0154 and Z / X = 0.0211 .

Conclusions : Our analysis implies a solar carbon abundance which is about 0.1 dex higher than what was found in previous analysis based on different 3D hydrodynamical computations .
The difference is partly driven by our equivalent width measurements ( we measure , on average , larger equivalent widths with respect to the other work based on a 3D model ) , in part it is likely due to the different properties of the hydrodynamical simulations and the spectrum synthesis code .
The solar metallicity we obtain from the CO5BOLD analyses is in slightly better agreement with the constraints of helioseismology than the previous 3D abundance results .