Carbon Offset and Trees: possibly not the best solution

April 21, 2009 -- Filed under My impact by Andrew Macdonald

The distance a new Clean Diesel will travel on a tank of fuel is astounding when you think back as I do to the dirty behemoths my dad drove us around in 30 years ago. Compared to the new TDI, these cars of “yesteryear” spewed massive amounts of carbon dioxide into the atmosphere. No one will dispute that. The math is easy: a 10 mile per gallon car compared to a 50 mpg model will emit five times the carbon over the same distance travelled.

Still, with all the clean and efficient cars on the market, we hear more and more about the opportunities to “offset” our carbon emissions from driving a fossil fuel vehicle. We hear slogans like “drive carbon neutral” or “offset your travel for only $20 a ton.” It would first appear that reducing our personal carbon footprint is a relatively trendy and simple thing to do – just plant some trees and there you are! Well, it’s not really that simple.

Trees appeal to all of us. Marketers love trees – they’re cheap and consumer friendly. And they’re currently the number one tactic corporations are using to talk about carbon although tree planting, in the big picture, represents only a small percentage of offset projects worldwide.

First, an offset should do one thing: displace the use of fossil fuel energy generation with clean energy. For example, offsetting the carbon from an average vehicle for one year amounts to about 5,000 kg of CO2. To effectively offset this carbon, the 5,000 kg of CO2 can be negated through the development of clean energy or energy efficiency measures. As an example; generating large amounts of hot water in hospitals often relies on coal-fired electricity. Replacing a “dirty energy” hot water system with a passive solar thermal installation, as the Toronto Hospital for Sick Children did in 2007, will “offset” most of the carbon from the displaced electrical generation through the harnessing of the sun’s rays.

Now let’s compare that scenario to planting trees as an alternative offset option. And remember, trees are great, the Lorax talked about trees, so we should plant trees! However, I am asking if they’re effective as a market offset mechanism.

The current debate around the issue of trees and offsets can be summarized like this:

• Measurability: the calculation of how much CO2 a forest will absorb is extremely complicated.

• Permanence: is it real and will it be ongoing.

• Leakage: the idea the deforestation is a more critical concern (currently 20+% of GHG). Displacing deforestation with new trees is important but will not reduce emissions.

• Timing: are the reductions now and not at some forecasted date in the future?

• Variety: the inherent challenges with monocultures and project planning.

Searching online will likely lead to further confusion, so I’ve linked a couple of interesting articles here from Grist, BBC news and the Guardian to help you better understand the tree story.

Now, does this mean there’s nothing else one can do? Quite the opposite! You may want to take a look at carbon offsetting companies leading in “non-tree” offsets and recognized as industry leaders. Try Terrapass, which operates out of the U.S. or Offsetters here in Canada.

Still curious? Calculate the carbon your vehicle and driving habits generate with the TDI Curious carbon calculator and then take your information to one of the offsetter sites to discover what it will cost to mitigate (in a meaningful way) your vehicle footprint.

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