Last week, we reported that only one in five children in the UK are connected to nature - you can see my blog on it here. Today sees the launch of Project Wild Thing, a documentary film about reconnecting children with nature, and I'm delighted to welcome a guest blog from the director of the film, David Bond. 

I'm a father of two small children. I look at their lives and worry. They spend the bulk of their time indoors, playing with plastic toys that spill out of cupboards, watching television, playing games on the computer and stroking apps on the iPad. What they don't do much is go outside.

They scream when I suggest we go out for a walk. My daughter, Ivy (6), prefers the television. 'How much do you love TV?' I ask. 'A hundred billion per cent', she replies, 'It's so relaxing'.

Two years ago, I decided to do something.

 My inner geek needed numbers to work with. I am a filmmaker. I strapped a camera to Ivy's head to find out how she spends her time: the bulk of it - over a quarter is on screens. Just 4% playing outdoors; the same proportion as she spends in the bathroom.

Yet when she does play outdoors, she enjoys herself far more. My children love nature - they love being outdoors. They just don't choose it.

All the science shows that getting outdoors is hugely beneficial to children and young people. It improves their health, reduces stress and boosts wellbeing. Just the view of greenery from an exam hall window helps students achieve better grades.

A UNICEF report finally convinced me. It compares child well being in Spain, the UK and Sweden. Across all three countries, children describe a 'good day' as being one where they spent time with their family outdoors. But in the UK, children get much less of this than elsewhere - less even than in colder Sweden.  When I ask Ivy to remember her ideal day, screens are not mentioned.  She talks about camping or playing together in the garden.

My daughter misses nature. She's not alone: millions of children are increasingly disconnected from the natural world. Children today spend half the time playing outdoors as their parents did. A third more children can identify a Dalek than can spot a magpie.

This retreat from the wild has serious implications. The British Heart Foundation has spoken up about the importance of an 'outdoors childhood' in tackling child health inequalities. Published in June, the State of Nature report, shows that tenth of species are at severe risk of extinction. If children don't learn hands-on about nature, why would they care to save it?

Their generation face tough environmental challenges. But why bother preserving the ash tree if they can't name it, have never climbed it or slept under it?

Disconnection from nature affects all children: rural and urban, rich and poor.

Making ‘Project Wild thing’ I spent 18 months travelling across the UK, talking to children of all different ages, races, and social backgrounds. The more I met, the clearer it became that, although all children want and need nature, they don't choose it or get it. The barriers they face are overwhelming, ranging from parents too afraid of strangers to let their children out through heavily congested roads to a lack of suitable green space.

Project Wild Thing addresses one barrier in particular: the commercialization of childhood.  Marketers sell my children everything under the sun.  They give them a view of nature so idealistic that the reality of their small garden in South London can never compete. Appointing myself the Marketing Director of Nature, I decided to 'sell' nature as the ultimate adventure. I wanted to compete with Disney and Nintendo.

I ran a major marketing campaign. I put posters up on billboards in railway stations across the country. I spoke to children in the most remote Scottish islands and in the busiest of city estates. But on my own, it was never going to be enough.

We all need to be Marketing Directors of Nature - and the best way to sell the product is to enjoy it ourselves.

Project Wild Thing will be shown in cinemas nationwide from the 25 October – screening details can be found at here.

Readers of my blog are also invited to the RSPB screening of the film in Clapham on Sunday 27 October. Find details here on how you can get tickets.