at least 25 percent of the trips will be newly generated.

That's dwarfed by the energy efficiency and CO2 emission improvement for the trips replacing car and plane trips.

In the study Kågesson also concluded that one million yearly single trips on a typical 500 km line resulted in a reduction of about 9,000 tons of CO2-equivalents. That is about the same amount as the yearly personal emissions of 900 EU citizens. Considering that building the line causes millions of tons of CO2 emissions, 9,000 tons is negligible.

Considering that the line will be there for many decades at least, comparing annual CO2 savings from just one million trips with construction emissions is silly. And road building and airport building have CO2 emissions, too.

_{*Lunatic*, n.
One whose delusions are out of fashion.}