The news that Derby has approved what promises to be Britain’s largest urban rewilding project so far is very welcome. The 320-hectare Allestree Park will, subject to detailed consultation, be given over to a range of habitats and perhaps even see the reintroduction of species such as dormice and red kites.

Urban rewilding – which is not the same as manicured green space, however extensive – can take many forms. They range from aiming to stem the rate of species loss by incorporating swift and sparrow boxes into new builds (there are now 247m fewer house sparrows than there were in 1980) to designating areas the size of Allestree Park.

In fact, some of the most successful projects have been accidental. Canvey Wick, a derelict area of the Thames estuary, reverted to a “brownfield rainforest” that is now home to nearly 2,000 invertebrate species, including at least three previously thought to be extinct. Rivers make natural wildlife corridors, working their way through cities, then linking them to countryside – to the uplands where they begin and lowlands where they end. The Guardian columnist George Monbiot gives the example of the River Wandle, which in the 19th century supported up to 90 factories (including William Morris’s), and was described as “the hardest worked river for its size in the world”. Now it teems with wildlife, and the local authorities have considered introducing beavers.

Urban rewilding, in itself, won’t make a massive difference to global heating. Only 6% or so of Britain is actually built on. But giving nature freer rein in parts of towns and cities could help to mitigate flooding, and to slow species loss. Importantly, about 83% of us live on the portion of the UK’s land that is classed as urbanised, and access to nature has also been shown to improve psychological wellbeing. One recent Canadian study found that adding just 10 trees to a city block had a big effect on people’s perceptions of their health; research is beginning to find that increasing biodiversity can heighten that impact. And on a more general scale, those who encounter wildness are more likely to fight for it.

The pressure for development means that there will always be tension with commercial interests: the Swanscombe Peninsula in Kent, another self-wilded brownfield site that is home to 1,992 species of invertebrates, including 250 of conservation concern, is now earmarked for the London Resort, the capital’s putative answer to Disney World. There is resistance to “mess” – nature does not obey tidy ideas of gardening; and sometimes there is fear – that rewilding means an increased presence of unpopular species, perhaps. Some want more green space for community use, while purists can argue that rewilding means no humans at all.

In these mid-pandemic, post-Brexit, austerity-bitten times, the financial arguments can be hardest to counter for cash-strapped councils, but the evidence that “we need nature as much as it needs us“, in the words of Jo Smith of the Derbyshire Wildlife Trust, is surely overwhelming. With a bit of imagination, flexibility and commitment, many more urban areas could follow Derby’s example.