How many trees do you need to plant to offset your car's annual CO2 emission?

Back in grade school, we were taught that cars are among the culprits that produce harmful byproducts like carbon dioxide. Plants, on the other hand, are the good guys as they sniff carbon dioxide and release precious oxygen. With environmental concerns being a top priority these days, many local car manufacturers and distributors have adopted tree-planting projects as their social responsibility program. But how many trees does one need to plant to make an impact on nature?

Four years ago, Honda Cars Philippines had one such tree planting project at the La Mesa watershed in Quezon City. Arnel Doria, a former Honda executive, recalled the event and wondered just how many trees it would take for a motorist to offset his or her vehicle’s annual carbon dioxide production. With data and formula from various sources, Doria got his answer.

According to Doria, an unleaded-fuel-powered car emits 115 grams of carbon dioxide per kilometer. An average trip of 25 kilometers a day (except during number-coding days) translates to 890 kilograms of carbon dioxide emitted to the atmosphere or 242 kilograms of carbon per year. One ton of carbon is equivalent to 3.667 tons of carbon dioxide.

Meanwhile, one hectare of forested area can absorb 15.873 tons of carbon a year. With the ideal forest density at 400 trees per hectare, the number of trees a motorist needs to plant and grow fully to offset his car’s annual carbon dioxide emission is six--every year.

This is the formula posted by Doria via Facebook:

0.242 ton of carbon ÷ 15.873 tons per hectare of forest = 0.0152 hectare x 400 trees per hectare = 6.09 trees

So how many trees do you need to plant this year?

Now that you know, when will you start planting trees to be able to say that you truly are a responsible motorist?

Photo from SXC.hu

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