Shimrod, please believe I appreciate your viewpoint and recognize that it is grounded in sound conservation principles

I'm not loudly proselytising for the random, and often inappropriate, planting of trees.
I'm not naïve enough to appreciate how unsuitable some are when planted in small gardens too close to buildings or infringing upon a neighbours boundaries and/or access to light
Neither am I too starry eyed not to recognize that what is gone is gone and our ancient woodland lost to 'progress' cannot simply be 'replaced' by parks and gardens.

Where we disagree is that I am in favour of the provision of new native woodland - not because it makes me feel virtuous - but to provide leisure and/or educational activities for future generations, habitats for wildlife and maybe even a source of renewable energy

I have seen it stated that 97% of all the wetlands in the Fens have disappeared over last four hundred years.
While there are movements to try to find ways to conserve wetlands, even in the face of the changing climate, there are also successful moves to create new wetlands from areas where they've been lost.

Is there not room for both approaches?

Although much of the grasslands in the UK below the treeline or away from coastal areas are historically the result of human activity created from woodland clearance and drainage of wetlands and maintained by grazing cutting or burning 'unimproved' land - so species rich - has undoubtedly declined in recent years as a result of agricultural intensification, over grazing, the inevitable building development, simple neglect or, some paradoxically, through woodland planting (point taken!)

I agree conservation is the next big challenge

An article in that well known green tinged tree huggers newspaper the Guardian (just joking) had an article a year ago beginning
"Planting forests as carbon sinks is a familiar idea.
Less discussed - but potentially even more significant - is the possibility of locking vast quantities of carbon into the soils of the world's dry grasslands. This could be achieved by changing the way we graze cattle …….
Even when the methane and nitrous oxide emissions of the cattle are taken into account, this "regenerative grassland management" holds the potential to significantly reduce the amount of greenhouse gas in the air."

Regenerating Grasslands