The data we are using as a basis for our CO₂ calculator, come from the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, as well as from the UN Climate Secretariat and the United Nations Framework Convention on Climate Change (UNFCCC).

Average CO₂ emissions from a car

The German Federal Ministry for Environment, Nature Conservation and Nuclear Safety provides average CO₂ emissions from cars. Per litre the average petrol car emits 2.32kg of CO₂, the average diesel car emits 2.63kg CO₂ per litre and per kilogram of natural gas, 2.23kg of CO₂ are produced.

Example calculation for a petrol car

A VW Golf for example, needs on average 8 litres of petrol per 100km. If you drive just 12,500km in a year, the calculation is as follows:                                              

12,500 x 0.08 x 2.32 = 2320kg CO₂ per year

So, if you have a petrol car all you need to do is follow the above and multiply the km per year, by the litres of petrol per km, by 2.32 and that will give you the amount of CO₂ produced per year.

Diesel and natural gas cars

for our CO₂ calculator we have used the data for a petrol car. In order to calculate the amount of CO₂ produced by a diesel car and to find out the number of trees you would need in order to neutralize this, all you need to do is multiply by 1.13. For a car that runs on natural gas, you need to multiply by 0.96.

Absorption of CO₂ by trees

The data we use to calculate the absorption of CO₂ by trees are also average values. Trees vary greatly in their absorption of CO₂ depending on; the type of tree, the amount of light, life expectancy, geographical location (degree of latitude), the quality of the soil and many other factors.

As a basis for our calculations for the amount of CO₂ absorbed by trees, we have applied data from the UN Climate Secretariat and the United Nations Framework Convention on Climate Change (UNFCCC). Whilst in central Europe an average tree absorbs around 10kg CO₂ per year, this figure is considerably higher for an average tree in the Tropics due to, among other things, much faster growth. 

A tree may absorb 600 kg CO₂

In planting a tree in the tropics of central America (and there lies our project in Honduras), a conservative calculation would be an absorption of 30kg of CO₂ per tree per year. In the beginning young trees absorb relatively little CO₂, but as they grow taller they begin to absorb a large amount.

It is true that trees die partially each year and by losing their leaves and branches they are also emitting CO₂. Therefore the figure for an average tree in the Tropics that lasts for 20 years will absorb 30kg of CO₂ per year.Thus a tree absorbs 600 kg CO₂ during its lifetime.