If a large tree needs to be removed from your property, don't let it just decompose naturally if you're concerned about climate change. Decomposing wood releases carbon back into the atmosphere. Instead, see if you can have the wood collected and turned into lumber. The only type of "usage" that won't fight climate change? Burning the fallen tree as firewood. Contact a lumberyard to see if they'll come and collect the wood from your yard.
ANDREWS MCMEEL SYNDICATION