There is a poster on the London Underground that takes your breath away.
It shows the huge head of a tiger staring straight into the face of a young boy. Their noses are nearly touching - and the gaze of the boy is equally intent.
In the space between their eyes is an invitation. It reads: 'Come within a whisker of nature's most breathtaking predator.'
It is an ad. for the Zoological Society of London.
I love the ad. and it's message. Even if the juxtaposition of the two heads is Photoshopped, it is an arresting design.
But it is the message I like to ponder most; which of the two is 'nature's most breathtaking predator'?
I looked up the threat posed by tigers.
Wikipedia tells me, the most comprehensive study of deaths due to tiger attacks estimates that at least 373,000 people died due to tiger attacks between 1800 and 2009, the majority of these attacks occurring in South and Southeast Asia.
In addition, tigers are known to attack each other. But I could find no word equivalent to 'genocide' indicating the mass slaughter of their own species - unlike the other predator of the poster.
Their population is certainly not increasing at a rate that threatens the natural resources of planet earth. Tigers are not mentioned anywhere, that I could find, as significant contributors to air or sea pollution. And there is no debate about whether or not they have contributed to climate change.
In fact, the Zoological Society says that tigers are desperately endangered and that, over the past decade, the wild tiger population has been decimated with a massive 95 per cent drop in numbers.
On the other hand, at last weekend's Awake in the World festival at the University of London I was handed a copy of a small Penguin book with a vivid orange cover, titled 10 Billion. It is by Stephen Emmott, the Head of Computational Science at Microsoft Research.
It contains numerous charts demonstrating that we are facing an unprecedented planetary emergency. In almost every area we are heading to disaster: climate change, air and water pollution, food scarcity, social conflict and over-population.
The title, 10 Billion, is the estimate for the human population by the end of this century. It is already at seven billion. And what the science shows is that it is this single species, our own, that is driving every global problem we face.
So, however the face of the magnificent tiger was chosen for the London Zoo poster, it is staring right into the eyes of the very creature that is most likely to render it extinct - and take down the whole planet as well.
Unless there is a massive shift of attitude and behaviour on the part of the seven billion of us who are here now, that is.
It's not impossible, but it seems we need to come within a whisker of ourselves to understand what we're up against.