Schemes to save the planet from climate change

all seem to involve fantastic amounts of money and incredibly complex bits of engineering to do things like increase the amount of ice in the Arctic. Why do they need to be so complicated?
I have put my paw up more than once and asked, "Why don't we plant more trees?"
I am told that there are schemes to plant trees but these aren't enough on their own. Oh  yes people have thought about planting trees in the Downunder desert and the Sahara but these aren't enough on their own. It's too expensive. It's too complicated. It's this and that and it won't work.
And so it goes on.
I know the answer of course. Planting millions of trees could save the planet but we won't ever do it because we lack the political and economic will to do it. It's too simple a solution. It doesn't involve expensive engineering which will make a lot of money for just a few. It won't give someone a Nobel prize or get their name into the history books.
The UN, for all the talk, doesn't really want to do anything. It would require too much cooperation. It might mean displacing people who have moved on to land they have cleared. They might need to be given aid for years while the trees grow. It might mean big business or government losing a source of income - and the power which goes with it.
Just imagine what would happen  if the Downunder government decided to impose a "tree tax" on everyone. Imagine the outcry if they said, "We are going to charge every single one of you enough to plant and maintain one tree each so that we have at least 25 million more trees in the next three years."  I wonder what the cost would really be? 
Yes, you have to decide where to plant them, provide the seedlings, the labour, the water and the management to keep them going. No, it wouldn't be cheap but...is it any more expensive than some of the other rather more complex schemes out there. 
Plant the right sort of trees and you have the potential to provide food, fuel, housing, clothing and more. What about more argan trees in the desert areas? Date palms? Then there are figs, olives and almonds. What would happen if you gradually added stone fruits like apricots and nuts like macadamias? 
And then of course you would need to maintain the existing trees and plant new trees. You could increase the number of trees over the next decade so that Downunder alone had planted say at least 100 million trees. By then the trees would be paying for themselves and more besides.
But, we won't do it. I am told it wouldn't work. I don't know why it wouldn't work - except that the answer is too simple and nobody is going to be able to say, "I saved the planet with my complicated scheme" - oh and there won't be any trips to Paris or Tokyo or wherever either.