When a big hurricane hits, it can create debris on the scale of $\mathrm{10^8 yd^3}$. Cities in Florida, Texas, and other affected areas are struggling to hire enough trucks and drivers to pick it up quickly. But aside from that, I noticed many of the areas have started to burn the debris once it starts building up.

Got to wondering... typically mulch comes in modestly pricey, and when free mulch is offered, it often goes quickly.

So assuming a fair portion of debris is mulchable and is of interest to other areas, and that we can acquire typical transportation resources, then we'll set up transfer from collection sites to those other regions rather than burning it. What would be the net pollution result?

If removed for mulch and such: trucking pollution + decomposition (- trees saved locally??)
If burned: the burning pollution.

Obviously it's about approximation rather than exacts, it's probably hard to appraise the different byproducts from burning versus decomposition, and a lot probably depends upon the way it is burned. But as a whole, can we get a rough estimate of comparable quantities/damage done... is it less pollution/damage even to truck it an average of 3000 miles? 1000 miles? 100 miles? 10 miles? Should it be burned on the spot (if done safely)? Would think there's got to be some way to get a very rough idea.

Certainly the best option if viable might be leaving it in place to decompose. But considering how upset people are getting at having debris around these parts a month later, exclude that option from the possibilities.

Trucking or burning, how do they compare?

  • $\begingroup$ By relocating debris, isn't that making one group's problem the problem of another group? What if the other group don't want the problem of having to deal with someone else's trash? Trash may be a harsh word but in this situation that's what debris is. Also, not all hurricane debris will decompose, particularly from urban environments. $\endgroup$
    – Fred
    Oct 13 '17 at 1:34
  • $\begingroup$ @Fred: It's in the assumption that a fair portion of it could be turned into mulch (or alternatively perhaps relocated to areas that aren't troubled by a small amount... rural woods or such?). But not important to the question I asked. Indeed, certainly not all of it can be repurposed either. But the part that can, assuming it were economically feasible, what would be the environmental effects. Edited to hopefully make sure that was clear. $\endgroup$ Oct 13 '17 at 3:50
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    $\begingroup$ The assumption that the debris can be turned to mulch is not valid. The mountain of debris in my front yard included carpet, tile, bamboo flooring, cabinets, wainscoting, dry wall, fiberglass insulation, furniture, appliances, etc., all soaked with category 3 (grossly unsanitary) water. Multiple sewage plants and two EPA superfund sites that flooded upstream of our neighborhood made the debris highly toxic. This happened throughout Houston. I'd rather buy a car that was known to be flooded than Harvey mulch. $\endgroup$ Oct 13 '17 at 10:44
  • $\begingroup$ Alright, totally agree there. Yet I'd think in most storms, a sizable portion of the debris is in individual downed trees? Harvey was a rather noteworthy mess! (Not the only one, I'd think Sandy and Katrina fit likewise) But in our cleanup from Irma, with very limited areal flooding (and the yuck that gets transported with it), I'd have thought most trees could be usable? $\endgroup$ Mar 31 '18 at 13:33

As the question was changed, my answer attempts to evaluate only the difference between burning and transporting. Please correct my values if my quickly found sources are inaccurate or you find more representing. I know there is quite a few unwritten assumptions that simplify this problem.

  • On average transporting via trucks emit 161.8 $\frac{CO_{2}}{short-ton-mile}$ (according to this Environmental defense fund handbook). Short ton equals to 2 000 lbs.

  • The amount of $CO_{2}$ equivalent from burning wood is $1900 + 200 + 70 = 2170 \frac{CO_{2} eqiuv.}{kg}$ from carbon dioxide, nitrous oxide and methane respectively (according to this article, the link to the source of these numbers fails so please comment if these numbers aren't correct).

Now we can write an equation out of this and solve for the kilometer distance that produces equal amount of carbon dioxide equivalent.$$\frac{2170\frac{CO_{2}eq.}{kg}}{161.8\frac{CO_2}{short-ton-mile} \cdot 0.0011\frac{short-ton}{kg} \cdot 0.6213\frac{mile}{km}} \approx 20000 km$$ This is quite a large number in my opinion. I would've expected less. So quite a long distance is needed until transporting produces more $CO_2$ pollution than burning.

  • $\begingroup$ Great answer :-D ... any input on the decomposition phase (indeed basically all organic matter decomposes... except in the burn situation... so it seems it should be in the equation [unless considering it as the relocated tree mulching may be taking the place for a different tree that was scheduled to be chopped down and mulched... but figure with such supply, more mulch would end up being produced/used in the end]) $\endgroup$ Oct 13 '17 at 8:07
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    $\begingroup$ Taking decomposition into account is really quite complicated. How long it takes and to what extent is some fallen tree for example decomposed depends on many things: moisture, organisms, burial or submersion in water etc. Leaving dead trees in a pile will surely keep carbon out of the atmosphere for longer, but decomposition can make them a source of methane. Also forests have more biodiversity with dead fallen trees. $\endgroup$
    – Communisty
    Oct 13 '17 at 13:22

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