27-05-2025
How urban rewilding could be an ‘antidote' to declining biodiversity
When we think of rewilding cities, we usually think of adding more greenery. Two-thirds of urban conservation programmes do focus exclusively on vegetation, according to a new review of thousands of scientific papers, but there's another side to this story.
From beavers back swimming in London's rivers after 400 years, to falcons nesting in American high-rises, there are also an increasing number of successful projects returning animals to cities.
A new study from the University of Sydney illustrates the benefits of these rewilding projects for city-dwellers as well as global biodiversity.
'They reconnect people with nature - an antidote to what researchers call nature deficit disorder,' says Dr Patrick Finnerty from the University's Faculty of Science, lead author of the global literature review published Sunday in the journal Bioscience.
'In today's urban environments, many children can name hundreds of brands but often not a single native bird or mammal.
'Bringing wildlife back into daily life improves mental health, fosters environmental stewardship, and reminds us that nature isn't something 'out there',' he adds.
Of the 2,800 scientific papers that Dr Finnerty and his team reviewed - on reintroducing species to areas where they once thrived - fewer than one per cent involved returning terrestrial fauna to cities.
Animal rewilding tends to happen far from urban landscapes, despite biodiversity loss being so pronounced in cities.
Other success stories include leopard frogs being restored to Las Vegas, howler monkeys breeding in Rio de Janeiro, and the reintroduction of the oriental pied hornbill to its historical range in Singapore.
In Australia, platypus populations are now growing on Sydney's periphery.
By 2050, around 70 per cent of the world's population of 10 billion people is expected to live in urban areas - a 20 per cent increase from today. This will necessitate a rapid growth of land-use change, especially in Africa and Asia.
To stop urban sprawl steamrolling over natural habitats, the researchers are calling for urban rewilding to be a key part of broader ecological restoration initiatives.
The authors say successful urban rewilding requires careful planning, community involvement, and addressing the threats that caused local extinctions in the first place.
For example, the recent reintroduction of small mammals, including the eastern pygmy possum, into an urban bushland reserve bordering housing in Sydney required serious invasive predator control efforts to help ensure the project's success.
"By integrating wildlife into urban landscapes, we have a unique opportunity to shape healthier and more resilient cities for future generations," says Dr Finnerty.
Rising from the Baltic Sea, Kriegers Flak is more than Denmark's largest offshore wind farm. It's a pioneering energy bridge between Denmark and Germany, helping balance electricity prices and strengthen energy security for both countries — all while providing a clean alternative to fossil fuels. As Europe seeks to secure its energy future, wind parks like Kriegers Flak are set to play a growing role.
'Europe needs more homegrown renewable electricity like this,' says Giles Dickson, CEO of WindEurope, an industry body representing over 600 companies. 'That means more energy security, which in turn means economic security and national security.'
The numbers are ambitious. The EU wants to grow its offshore wind capacity from 20 gigawatts today to 360 gigawatts by 2050. It's a massive undertaking, backed by policy support and rapid technological innovation.
At the Port of Esbjerg on Denmark's west coast, the future is already taking shape. From here, Swedish energy giant Vattenfall remotely manages more than 1,200 offshore turbines across four countries. Algorithms are playing a growing role in this digital transition: according to Laura Ørsted, who heads Vattenfall's operational control centre, automation is key to keeping up with the growth in turbine numbers.
As turbines get taller and more powerful, ports like Esbjerg are expanding to meet the logistical demands. Having already handled 80% of Europe's offshore wind installations, the port is now reclaiming more land to accommodate next-generation equipment.
'One of the challenges with offshore wind is that it needs very large port space, port capacity — and that's also why there aren't sufficient offshore wind ports in Europe today,' says Dennis Jul Pedersen, the port's CEO. 'We are lucky here that we have been able to develop the port in line with what the industry needs, and we will also be very, very busy going forward.'
Getting turbines installed at sea isn't easy — or cheap. Specialised vessels like the Wind Osprey, operated by Danish offshore services company Cadeler, are critical. With extendable legs that reach down to the seabed, they form stable platforms for lifting and assembling massive components.
'Everything's getting bigger,' says Captain Matthew Christie of the Wind Osprey. 'We've just had a new crane fitted — it's longer and has a bigger lifting capacity, because the tower sections are taller now.'
A single day of operation for these ships can cost hundreds of thousands of euros. And once the turbines are up, keeping them running smoothly is another major challenge.
Offshore turbines are battered by salt water and storms. Unlike land-based units, they're hard to access — requiring boats or helicopters, and only during calm weather. This makes maintenance one of the most expensive parts of offshore wind operations, accounting for up to a third of total costs.
'The cost of maintenance is actually quite a large fraction of the total levelised cost of energy,' says Simon Watson, professor of wind energy systems at TU Delft. 'There's a big interest in trying to reduce that to make offshore wind energy more cost effective.'
The sector is increasingly looking to robotics as part of the solution. In Latvia, a company called Aerones has developed a climbing robot that can inspect and repair turbine blades more quickly — and safely — than human workers.
These robots can sand, coat, and inspect blades for damage, dramatically reducing downtime and keeping the turbines turning.
'The largest blades in the world are exceeding 120 metres,' says Aerones CEO Dainis Kruze. 'We optimise the robots for speed, so the turbines have far less downtime while we're doing the job.'
At their Riga factory, Aerones is now producing dozens of these machines each month to keep up with demand. The long-term vision? Autonomous maintenance robots for every turbine, overseen by technicians rather than operated manually.
'As the robots become smarter, we try to implement algorithms so the operator would be kind of overseeing the AI agents doing the work, not so much being involved himself, moving the robot left or right,' adds Aerones CTO Janis Putrams.
Despite the challenges, momentum is strong. The WindEurope Annual Event in Copenhagen highlighted just how much investment, research, and international collaboration is going into this growing sector.
By 2030, the European wind industry — both onshore and offshore — is expected to employ over 900,000 people and contribute more than €100 billion to the EU economy.
'There are the jobs, the growth, the investment that comes locally from building and operating these wind farms and manufacturing the turbines and all the equipment, the grid equipment, that is part of wind energy,' says WindEurope's Giles Dickson.
As Europe works to reduce reliance on fossil fuels and unstable energy imports, offshore wind is fast becoming a pillar of its strategy. Scaling up isn't easy, but with innovation and smart investment, the continent is turning its coastal winds into a powerful force for change.
