Sweden’s CO2 emissions after the trees’ CO₂ absorption—according to the Swedish Environmental Protection Agency’s low figures—are only 13 million tons per year. New calculation for the number of trees to be planted in deserts to offset the EU’s emissions.

 According to the Swedish Environmental Protection Agency, the forest absorbs about 33.3 million tons of CO₂, leaving 13 million tons of CO₂ remaining. Each country should ideally plant native trees or, for example, establish plantations or water extraction projects in arid regions such as the Sahara, South America, Australia, the USA, etc. 

For Sweden, the number of trees planted would be minimal, but it would still represent a significant and meaningful contribution—especially as part of foreign aid—since water extraction (without encroaching on existing water sources) could simultaneously irrigate crops and support livestock.

Regarding the template of 25 kg and the assumption of 66 times lower uptake in Sweden, as concluded by the Swedish Environmental Protection Agency, Gemini AI responded as follows:

This is a very relevant question. The 25 kg CO₂ per tree per year figure is not tied to a single Swedish authority or research institute but is a common and simplified average used in:

• Climate Compensation and Tree Planting Projects: Organizations and companies selling climate compensation or running "plant a tree" campaigns often use this figure to provide a simple estimate for customers.
• General Estimates: The figure typically represents the maximum annual gross uptake of a medium-sized, fast-growing tree during its most active growth phase (approximately 10 to 50 years), often without accounting for emissions from forest management, decomposition, or logging.

Where does the 25 kg figure come from?

Searches show that there is no specific source that "invented" the 25 kg figure. Instead, it is a range that aligns with international studies on fast-growing trees:

• According to some sources, a tree in its fast-growing phase can absorb between 10 and 40 kg of CO₂ per year, with 25 kg serving as a useful average. Some sources even mention up to 50 kg per tree.
• The figure of 25 kg/year is often cited for an average 35-year-old tree.

This 25 kg template focuses on what a single tree can do under optimal conditions. However, official Swedish statistics focus on 0.38 kg (net) as the average for the entire forest, including all trees from saplings to decaying deadwood.

In summary, 25 kg is a widely used and commercially applied template for gross uptake, rather than an officially calculated net uptake for the entire Swedish forest.

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I now realize that the AI I used did not subtract the CO₂ emissions from vegetation when calculating the 20–30 billion trees needed to offset the EU road vehicle fleet's CO₂ emissions (see the calculation https://larsschnellsblogg.blogspot.com/2025/11/the-eu-road-vehicle-fleet-emits.html). 

However, I instructed Gemini to redo the calculation.

What I mean is: Did you fail to subtract the CO₂ absorption of fast-growing trees planted in the Sahara from the existing older forests' expected CO₂ reduction to arrive at a lower figure than 28 billion?

Calculation Example: Tree Planting vs. EU Road Traffic Emissions

This is an excellent way to calculate it. By subtracting the EU's existing uptake from road traffic emissions, we determine the net need for new carbon sequestration.

Here is the answer, based on the latest official EU statistics for uptake:

1. Calculating Net Need We use the established figures:

   • Emissions (EU Road Traffic): Approximately 700 million tons (Mt) of CO₂e per year.
   • Existing Uptake (EU Forests/Land, LULUCF): Approximately 274 Mt CO₂e per year (net, according to EU's official 2023 statistics).

   Formula: Net Need = Emissions - Existing Uptake Result: 700 Mt - 274 Mt = 426 Mt CO₂

   This is the remaining net deficit that must be compensated for through new tree planting or other measures.

2. Calculating the Number of New Trees (Using the 25 kg Template) To absorb the remaining 426 Mt, we use the high template of 25 kg/year per tree, commonly used in compensation projects:

   • Convert the net need to kg: 426 Mt = 426,000,000,000 kg
   • Divide by the absorption capacity of the template: 426,000,000,000 kg / 25 kg/year
   • Result: Number of Trees = 17,040,000,000

Conclusion

The answer is that approximately 17 billion (17.04 billion) new trees, each absorbing 25 kg of CO₂ per year, would be needed to fully offset the EU's road traffic emissions after accounting for the CO₂ already absorbed by the EU's existing forests.

Comparison Between Gross and Net Methods: