Is modern living resulting in more people becoming disconnected from green spaces and the natural world, at the expense of our health and well-being?
Most concern is centred around children, who - say campaigners - are missing out on opportunities afforded to previous generations, ones as simple as climbing trees or getting their knees dirty.
In an increasingly urbanised, electronic-based, risk-adverse world, the adults of the future are displaying the symptoms of "nature-deficit disorder".
The term was coined by Richard Louv, author of Last Child in the Wood.
In the introduction to his book, he said that over the past few decades the way children understood and experienced nature had "changed radically".
"The polarity of the relationship has reversed," he wrote.
"Today, kids are aware of the global threats to the environment - but their physical contact, their intimacy with nature, is fading.
"That's exactly the opposite of how it was when I was a child."
Mr Louv acknowledged that nature-deficit disorder was "by no means a medical diagnosis".
But, he added: "It does offer a way about the problem and possibilities - for children and for the rest of us as well."
Consultant Tim Gill, author of the report Sowing the Seeds: Reconnecting London's Children with Nature, agreed that the phrase did not have any meaningful clinical basis.
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