Planting Trees Affect on Climate Change
by Tim McGee, Western Massachusetts 
on 12.14.06
A new report from Lawrence Livermore Laboratory suggests that planting a tree does not always provide the climate benefits some might expect. The primary point of the article demonstrates that there are no easy solutions and we need to change the status quo more dramatically then simply planting trees. However, as we have seen in previous posts (here, here, here…and more) planting trees as an offsetting strategy or a carbon sink is a contentious issue. Click through for a quick review of what the science is telling us.
The new model shows that trees planted in the northern climates may actually increase local warming by up to 10 degrees Fahrenheit, temperate forests have no net impact, and tropical forests are still the favorite carbon-sequestering environment. While this is an interesting result, it is important to keep in mind the more complex interactions trees and forests have with their environment. Just recently, a report in the prestigious peer reviewed journal 'Science’ demonstrated that temperate forests are better long term carbon sinks then anyone had previously thought. The waxy carbon of the plants is maintained in the forests soil for 10,000 to 100,000 years. That is a large carbon sink.
Planting trees today might not have a large short-term effect on reducing greenhouse gas, as recent evidence suggests, we are experiencing accelerating CO2 emissions despite current strategies. But, a healthy ecosystem, including forest canopy, may provide other benefits, such as long term carbon sinks in the soil. There is no single solution to global warming. Increasingly it appears that planting trees is not a good strategy to offset carbon emission within a relevant period of time. The environmental benefits of trees are manifold, but they are only human plants- they can’t do everything. :: Lawrence Livermore ::Science Daily
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Something is counter-intuitive about such inconclusive or contradictory sounding studies. Given the choice of clearing a northern temperate forest for paper making, thus liberating, ultimatelly, all carbon in the stems, branches, and leaves into the atmosphere, versus not clearing it, which one is clearly better for the climate? I suspect many of these scientists are not seeing the forest for the trees.
I think you are misunderstanding JL. They are saying planting a tree may not have the imediate short term benefits everyone thinks it will. I remember reading about this several times in the last 15 years. I don't think this is anything new, people just don't want to believe the possibility that panting a new tree won't immediately help. And your hypothetical choice is flawed. No one is talking about cutting down trees and it having no effect. But planting new trees. If anything the reports encourages keeping old forests.
Focusing on carbon issues misses big picture of the environmental change resulting with reforestation.
The carbon conversion and storage possible pales in comparison with the changes in weather and wind patterns, water retention and salinity, species diversity, small particle soil erosion (with the resulting effects on water-way silt accumulation and the resulting changes in the abilities of water bodies to grow vegetation and support aquatic ecosystems).
These functional subsystems dwarf a single trees ability to impact the carbon balance, and in general big picture ecosystem funtionality should be the goal.
The most impactful forestation goals should be areas that are experiencing a desertification trend. Not only does desertification ruin potential carbon cycle storage and conversion, it also allows release of long term carbon stores in deep sub surface storage (much like the problem in the rain forest, which exposes hundreds to thousands of years of carbon storage to atmospheric release).
While I'm all for the use of Kenaf and other more eco-friendly ways of creating paper products, I've always wondered why the practice of using commercial tree farms (cutting down and replanting trees for use as paper stock - as opposed to just clear-cutting arboreal forest) isn't acknowledged as a pretty effective carbon sink.
Trees convert CO2 into cellulose, lignin and other high-carbon solids, which are processed into paper, which eventually finds itself disposed in landfills, which, as has been extensively shown by exhuming 100 year old newspapers over the years, don't tend to be very good at breaking down low-moisture organic substances. Cover the landfill with dirt and all that carbon just sits there, while the new strand of replanted forest pulls the next couple million tons of C02 out of the atmosphere, destined for burial.
Heck, why don't we just skip the middle man and start burying whole trees, or dumping them into the Mariana Trench (or, if that has a disturbable ecosystem, some really barren patch of ocean floor)? You have cockamamie schemes to divert C02 into old oil wells (acidifying the water and causing the limestone to wear away, releasing the CO2 back into the atmosphere in a couple of decades) - why not store carbon-rich solids?
Good comment thread. But I do wish to add a thought to BrianE's points. Toilet paper does not go to the landfill for most of the worlds' population. In fact landfills are a common management practice only in North America! The rest of the world uses incineration and open dumping, where oxidative breakdown is the dominant process.
The most problematic element of biosequestration by trees is the 'temporary' nature of the carbon store they provide. We need to develop ways of reducing the flowback of Carbon to the atmosphere. We are working on this idea of a sequestration farm. The trees are grown to maturity and then dumped in the sea. Under the anaerobic conditions down there the timber may not relinquish its C for a thousand years.Meanwhile the process can be repeated 10 times.
From the study: “The darkening of the surface by new forest canopies in the high latitude Boreal regions allows absorption of more sunlight that helps to warm the surface."
This is likely do to evergreen trees. I wonder if planting deciduous trees that lose their leaves seasonally would solve the problem?
http://www.physorg.com/news82910219.html
Says something about that here.
I wonder if some kind of massive marine based aquaculture using plankton might not be worthwhile exploring with biosequestration in mind
Plankton photosynthesise far quicker than trees, shrubs and even grasses, andhave the spin off benefit of providing a food source at the bottom of the foodweb. Admittedly, this predation ends in the re-release of much of the carbon which is used as fuel by those preying on it, but much of it is retained in the seawater, and some as sediment, which falls to the sea floor there to remain under pressure for a very long time.
Some single celled organisms (e.g. coccolithophores) consume significant CO2 in seawater, calcify and fall to the seafloor as sediment.
Low ozone is hazardous to phytoplankton, as it allows destructive UV to inhibit photosynthesis, but as I understand it, it's possible to mitigate UV's penetration of the sea surface by disturbing the top layer of molecules with a fine mist of water (the same process is being used experimentally to protect coral). If An aquaculture operation were set up drawing local power from some wind, wave or OTEC-based system, then a simple pump could continually disturb the water surface with a fine spray and promote the growth of endogenous phytoplankton.
Any comments?
Fran
This study can't see the forest for the trees.
And what the heck is term "local warming"? That's BS. Local warming has very little affect on the overall planetary temperature.
Who funded this study, Exxon?
Northern forests sequester tons of carbon. If we can expand sustainable forests, vs. just plant trees, then we create an environment that will sink huge amounts of carbon, thus reducing the greenhouse effect.
The greenhouse effect is the problem. This study ignores that as well.
We do have to get past the mindset of "tree planting" to a deep ecology view of the forest process.
If we expanded the worlds forests there would be a huge impact on the CO2 levels reducing the net amount of greenhouse gasses and the resultant greenhouse effect, which is now spking geometrically.
This study can't see the forest for the trees.
And what the heck is term "local warming"? That's BS. Local warming has very little affect on the overall planetary temperature.
Who funded this study, Exxon?
Northern forests sequester tons of carbon. If we can expand sustainable forests, vs. just plant trees, then we create an environment that will sink huge amounts of carbon, thus reducing the greenhouse effect.
The greenhouse effect is the problem. This study ignores that as well.
We do have to get past the mindset of "tree planting" to a deep ecology view of the forest process.
If we expanded the worlds forests there would be a huge impact on the CO2 levels reducing the net amount of greenhouse gasses and the resultant greenhouse effect, which is now spking geometrically.