Planting trees to suck CO2 - yes or no?

Albe

So trees as they grow suck CO2 from the atmosphere. All good.
But unfortunately they don't last forever. Eventually they die, so whether it's fire or they just rot naturally they release back that CO2 into the atmosphere.

I understand they are other good reason why more trees do more good than not. They help biodiversity and wildlife, housing insects for example.

But do they provide a net reduction of CO2?

Skandi

That depends on what happens to the tree after it dies. If it gets buried in the right conditions then yes that CO2 can be locked up for millions of years, otherwise the tree "only" takes it out of the atmosphere for 50 or 300 years depending on the tree.

So if you plant a Beech tree today and it lives it's full life it will lock up co2 for 150 years, so long as someone else plants one in 50 years and another in 100 years those trees combined will always have more CO2 locked up than if no one had planted the tree to begin with.

Dovefromabove

It's not just the tree you plant ... it's the cumulative effect of the baby trees it produces when the squirrels and jays etc who live in that woodland plant those nuts ... another reason why re-wilding works.

punkdoc

If we aim to always end up with more trees than we started with, at a certain point in time, we will reduce the CO2 levels at that time.
There are also beneficial effects due to: shading, pollution reduction, etc etc.

Fire

Water slows down the release process, so places like peat bogs lock up moss carbon for millenia, releasing very slowly. Oceans also.

BobTheGardener

Skandi said:

That depends on what happens to the tree after it dies. If it gets buried in the right conditions then yes that CO2 can be locked up for millions of years, otherwise the tree "only" takes it out of the atmosphere for 50 or 300 years depending on the tree.

So if you plant a Beech tree today and it lives it's full life it will lock up co2 for 150 years, so long as someone else plants one in 50 years and another in 100 years those trees combined will always have more CO2 locked up than if no one had planted the tree to begin with.

Agreed.  They make coal if buried under the right conditions, which to all intents and purposes is solid carbon.  As you say, it's down to numbers, which would become much simpler if we could wean ourselves from digging the fossilized stuff up and converting it back to CO2! <sigh>.

StephenSouthwest

They also hold carbon if, at the end of their life, they become shelves, or toy tractors...

wild edges

Fire said:

Water slows down the release process, so places like peat bogs lock up moss carbon for millenia, releasing very slowly. Oceans also.

Sadly when politicians and lobbyists own bogs and moorlands and like to manage them for shooting rather than flood prevention and carbon capture then this type of detail gets glossed over in favour of planting imaginary tree numbers. We promise to plant millions of trees (somewhere) always sounds better than admitting you've been degrading some of the best carbon sinks we have.

Protecting certain marine habitats can be just as important as planting trees as well but the government seem to hate that idea too.

There's a lot more to trees than growth and decay cycles though and if they're coppiced or harvested for biomass to replace fossil fuel use or the wood is locked away in timber-framed houses for example then they can be a way to mop up excess CO2 now while we get emissions back under control. It has to be the right trees in the right places though or it will do more harm than good.

Fire

Much better to not plant trees, but commit to not cut the ones you have, not drain wetlands, not build on woodlands, let ocean forests thrive, not dig up peat, not mine coal, let wild scrubland grow on non-agricultural land.

102 ancient woodlands are in the way of HS2. Thousands of wooded areas across the country are being threatened by housing developments, like those in East Grinstead.

philippasmith2

Be interesting to see if the likes of HS2 pop up at COP won't it ?  Personally, I won't be holding my breath.

fidgetbones

In this area the local council is giving away 150 apple trees to show its green credentials. On the other hand they are allowing mass devastation of protected woodland to build more houses.