HS2: Swings and Roundabouts?

Like other Ecology-minded folk in the UK, I am not a supporter of the High Speed 2 (HS2) train link. I (like many others) just think that the expense and the environmental damage incurred, is too great. Having said that, one can't help being impressed by the plans (even if they look a bit like 'greenwash') for the Colne Valley Western Slopes development ((https://www.theguardian.com/uk-news/2021/mar/03/hs2-to-rewild-127-hectares-around-its-10-mile-chilterns-tunnel). The plan is to use the 3 million tonnes of chalk, excavated in the construction of its 10 mile long Chiltern's tunnel, to 'rewild' 127 hectares of chalkland (as well as cutting down the contractor's emissions for moving the rubble). The intention is to increase the amenity for humans and wildlife. The area will be seeded with 70 grass and flower species. In addition, 32 species of natural trees and shrubs, will be planted. The development is designed to generate distinct microclimates (such as basking areas for reptiles and butterflies). This might be quite a nice addition for people in Chiltern's area but the destruction of ancient woodland elsewhere, pushes the balance for HS2 well into the negative zone.