Does planting trees help combat climate change?
The short answer is Yes. Trees can absorb one of the greenhouse gases, CO2.
Here is how it works: the tree breathes in CO2 and uses photosynthesis and the sun's energy to split the molecule. The carbon is retained in the tree and converted into new wood. The oxygen is expirated by the tree.
As long as the tree then lives, the carbon is trapped in the wood.
Ideally, if you want to use trees to soak up CO2, you need to plant species that live a long time, centuries.
Oak trees can live for centuries - there is an oak tree outside Windsor Castle that is about a thousand years old and still going strong. The oak in the image above is in King's Walden, England and is 850 years old. Chestnuts, elm, sequoia, and other hardwood trees, will also live for centuries, and thus keep carbon trapped fora long time. Plus they look great.
So get planting!
If we could indeed reforrest, the earth would be in a much better place. Alas, lots of forests are being chopped down, for example in Indonesia.
The deforestation in Indonesia is caused by demand for palm oil. If we stopped using it they would stop clearing forests to plant it.
I believe they've made tree planting part of the Paris Climate Change agreement. So countries like India and Brazil have agreed to increase the amount of forest cover as part of the deal.