Thursday, March 12, 2009

Planting our way out of climate change?

Tony Juniper has a new op-ed piece in the Guardian about China's attempt to green up. China's efforts might have, or probably will have (if they do it right and plant at least semi-natural forest) a positive impact on soil erosion (China is suffering from a serious dust-bowl), though we don't know by how much, and will take a little carbon out of the atmosphere.

But Tony is right, planting trees will have very little impact on the climate as a direct impact. Young trees and newly established forests don't accumulate much carbon very fast. It usually takes decades, especially in temperate zones, for forests to reach their maximum carbon accumulation rate. Check out the graph below, derived from direct measurements of temperate forests and their carbon accumulation:

The study referenced here is Gough et al., 2007, ‘The legacy of harvest abd fire on ecosystem carbon storage in a north temperate forest.’ Global Change Biology 13, 1935 – 1949.

Look at the graph. It is not until around 50 years since disturbance that a forest is at its maximum C accumulation rate. Again, it takes decades

This probably speaks most to the need to keep standing forests just that - standing.

How does this blog post relate to the paper industry? The answer is that we as a society must move the paper industry toward leaving more forests standing for longer: older forests are better at accumulating carbon from the atmosphere than newly established forests.

The scariest scenario from the paper industry is that they are moving toward using more biomass from trees, and thus taking more and more trees from forests that might otherwise be left to absorb more and more carbon.

The better option? How about using less paper and recycling more?

1 comment:

writing a dissertation said...

I think according to Greenpeace, farmers in Central America illegally rip up vast tracts of native forest for cattle and soybean production without any consequences and companies who buy timber from private land owners contribute to massive Deforestation of the Amazon Rainforest