carbon fixation

The cedar that grows around here (high desert) will ruin a chainsaw blade

More likely it is wind blown sand that impregnates the bark. thats a common enough problem for farm foresters here.

Ah yeah. There's a certain amount of sand available to become airborn.

That looks like wood that has undergone destructive distillation, which is more than just drying out the water. It's actually the way charcoal is made. Wood is heated in a sealed container at combustive temperatures for an extended period. This boils away all of the volatiles naturally present in the wood (Water, methanol, et al.), decomposes many of the more complex compounds present into additional volatiles, heavier carbonaceous compounds, or, predominantly, elemental carbon. It is more or less the same process by which petroleum, coal, and eventually, diamonds are created within the earth, though with only the slightest fraction of the heat, pressure, or time that the geological phenomenon requires.

Or it could simply be a misleading picture.

@ JTT
There is also the factor of photoinhibition to take into account. In strong sunlight, electron donation from the oxygen evolving complex in photosystem 2 can not keep up with demand so highly oxidised p680 burns out the nearest thing to it. This destroys the D3 polypeptide and effectively halts photosynthesis.

She/he is confused by the political nature of co2 and weather change that so many feel is not true.

Don't make it more confusing for her, it's man caused weather change that so many know is not true.