The Trouble with Trees

Fire

The California wildfire season in 2018 is estimated to have released about 68 million tons of CO2 into the atmosphere. Thats equal to about 15% of all of the emissions in California.

In the summer of 2019, there were more than 38,000 fires in the Amazon that were man made.

About half of the dry weight of the tree is carbon.

Tree Monoculture Plantations

Half of the areas pledged by countries for tree planting are monoculture plantations. Planted with just one single species planted over thousands of acres

Monoculture tree plantations such as eucalytpis are harvested about every 10 years, releasing much of the carbon stored in the tree back into the atmosphere. Much of it is used to make paper, which when discarded, releases carbon into the atmosphere

Monoculture plantations often focus on getting the maximum yield as fast as possible, so they apply fertilizers which contributes to Nitrous oxide, a greenhouse gas.

They will store only about 1/40th of the C that natural forests do long term.

So unfortunately many of the pledges for tree planting are not going to deliver the C reductions that we were expecting.

Conifer Monoculture plantations are very densely stocked and cut out the light to the ground, so have very poor biodiversity.

Biodiversity of the forests is critical for getting the most C reductions

Mixed tree plantings, with as many different indigenous species as possible, is the way to go.

And another big problem with trees, is space. There is not enough land in the world, to plant trees, to offset all of the C emissions from fossil fuels.

Research within the last two decades points to another problem with planting trees to offset emissions. Once a tree becomes mature and saturated with carbon, it may actually start releasing that carbon back into the atmosphere, turning into a net CO2 emitter, according to studies by the Intergovernmental Panel on Climate Change and the Hadley Centre for Climate Prediction and Research in the UK.

Trees are important part, but not the other method. 

We need to go to the oceans. The oceans cover 71 percent of the Earth's surface

(From Climate change: the trouble with trees | The Economist on youtube)