No it’s not an “April Fools gag”, treecoins.org has more info.

And ‘Paraguay Tree Coin’ which aims to raise 10 million trees (on 127,000 hectares - about 0.78 millions ไร่) is a good example of what involves. Raising trees is hard in today’s climate and people’s wants (money first, then buy nice place to live – there will be no Nature - nothing for money to buy when we destroy all to make money).