1 Billion trees (Nah! half a billion trees really)
Billion trees (Well actually half a billion extra trees)
As with any government project it will be interesting to see how this develops.
Ironically on one hand the government is paying to plant millions of trees and on the otherhand the government is paying $millions to destroy wilding pines.
Over $10 million per year https://www.mpi.govt.nz/protection-and-response/long-term-pest-management/wilding-conifers/
It's estimated 20% of New Zealand will be covered in unwanted wilding conifers within 20 years if their spread isn't stopped. Wilding conifers already cover more than 1.8 million hectares of New Zealand. Despite control efforts, they have been spreading at about 5% a year. That's about 90,000 more hectares a year.
Until 2020 New Zealand has utilized cheap (fraudulent?) Kyoto credits to offset emissions http://morganfoundation.org.nz/new-report-climate-cheats/
The new regime under the Paris agreement is expected to turn up the heat in the fight against Climate Change.
New Zealand’s net emissions that need offsetting are to the tune of 50mt CO2-e per year.
The Billion trees program is part of this plan to manage ETS under the new regime.
But how many trees need to be planted to offset 50mt of emissions?
The government has issued tables to calculate ETS payments and values for forestry
On average a hectare of Radiata sequesters about 34 tonnes of CO2 a year, thus an extra 1.5 million hectares of pine would cover the net emissions of 50mt. Which if planted at 1000 per hectare would be 1.5billion extra trees.
So really the billion trees program is going off at half cock with half a billion trees, it is only a third of what needs to be done
The big question is.... IF all these trees are just planted to offset emissions or to earn carbon credits, WHAT HAPPENS when there is sequeston failure, eg fire or disease? Who pays? Whereas if they are harvested and used as Fossil fuel replacement then they have done their job.
Just some forestry numbers
Carbon stock for a 25 year old forest per hectare Pinus radiata in the Auckland region (expressed as tonnes of carbon dioxide per hectare). Harvestable timber 715 tonnes, non harvested residue 317tonnes
Typically, about half a tree’s dry weight is carbon, which you can multiply by roughly 3.7 to get CO2
An example of forest harvest yields
24 and 25 year old trees planted at 1000 per hectare, pruned and thinned to 350 stem per hectare. Key statistics averaged across the two blocks (both Radiata pine) are:
- Per hectare log yield of 875 tonnes. (probably 810tonnes Co2)
- Net income (stumpage) per hectare $61,430
- Net income (stumpage) per hectare per year of $2,507
- Net income (stumpage) per tonne of $67.63