If we cultivate trees, then remove them from the earth and atomize them into the air, then plant more trees, they're a renewable resource but it's still causing climate change.
The effects of climate change are not instantly reversible. Imagine shifting weather patterns dry up a wetlands. Removing carbon from the atmosphere does not recreate that biome
CO2 doesn’t disappear from the atmosphere the moment you plant trees. In fact, burning wood is worse than burning coal here, because, for the same amount of energy provided, burning wood is going to emit more CO2 than burning coal.
> Energy output is directly related to carbon content. More energy density from coal mean more co2.
No. It means you need to burn a larger volume of wood to get the same amount of energy. And when you increase the volume, you increase the emissions. The first sentence of this quote may be true, if we are talking about absolute amounts, but then in the second sentence density is a ratio (energy to volume), which is why it’s not true.
I don’t know all that much about relative PM2.5 emissions, but a brief search shows a paper, which argues that PM2.5 emissions depend more on combustion conditions than fuel type[1].
> A ton of coal will create much more co2 than ton of wood, isn't it?
Yes. But that hardly matters.
> For the same amount of energy the result should be similar amount of co2.
No. Apparently, wood is estimated to emit 30% more CO2 than coal for the same amount of energy[1].
> Coal is worse for people because burning it creates many unhealthy chemical components. Sulfur, heavy metals, etc
Is it more than when you burn wood though? I’m not knowleadgable enough to answer this question. I found one link about it[2], but currently I don’t have time to read it. In any case, the fact that it produces more CO2 than coal is a good argument against wood in my eyes. My argument is against wood, not in favour of coal. Coal is just a benchmark to measure against.
Not from a carbon perspective. Forestry isn't cutting down ancient forests and then randomly thinking it would be nice to plant some new ones. Trees are a crop. They are planted, left to grow, and then harvested, in a cycle.
It’s going to take time for a new tree to consume the CO2 produced by burning a tree. If instead you leave a tree standing and burn coal, you will produce less CO2, so it’s going to take less time to consume it (and the older tree is going to do it faster than a young one).
Moreover, it’s not only a question of net emissions. It’s also a question of location. People burn wood and coal in their homes and that affects the air most near them the most. It is the worst near cities, where you can’t plant a new forest. Instead just think about how the local air is going to be affected if people burn there 1MWh of wood vs coal. Because trees are not going to help here, if they're planted far away.
And, when trees die naturally, they don’t emit CO2 at the speed that they do when they’re burnt. It happens much slower, so it’s not that much of a problem.
Mind you I’m not advocating for burning coal. I’m advocating against burning wood.
Ok, there are many rural properties in the world populated with trees. These trees naturally fall and contribute brush. Firefighters and forest management will tell you to clean up the brush by burning, otherwise it will decompose (still co2) and eventually lead to a natural wildfire (same effect). Better to burn it for heat than outside for nothing. What would you do instead?
In this instance I’ll say burn it if you want. Although it leading to a natural wildfire is highly dependent on local climate. Where I live, for most of the year it’s too cold and humid for anything like this to happen, except during maybe 2 months a year. But I appreciate that in places like California or Australia it may be different.
