Climate change has become one of the biggest, most complex issues of our time. And the warnings from some of the world's leading scientists are getting louder.
But sceptics remain. Despite the data, many are unconvinced that the science is on target.
So, we ask: Is climate change man-made and, if so, what can we do to stop it?
From the crumbling ice caps of the Arctic to the shifting sands of the Arabian Gulf, Al Jazeera takes you around the world to see first-hand the impact mankind is having on our planet.
Against the backdrop of a major UN climate change conference in Qatar, join Nick Clark as he looks at the efforts that have been made to address climate change, the failures of previous agreements and the challenges that lay ahead.
|Who will save Planet Earth? - by Nick Clark
Think of Planet Earth viewed from outer space. In the cosmic vastness, you see a brilliant blue speck - our home.
Zoom in to a remote island community deep in the Arctic, not far from the North Pole, called Qerqetat. It is spectacularly located on the edge of the Greenland ice sheet. Glaciers sweep down into the sea like snowed-up freeways; icebergs with their azure underwater blues stand sentinel in a perfect flat ocean; Arctic terns soar and dip into abundant waters.
Ashore, a dozen ramshackle wooden houses in varying shades of rusts and yellows straddle high ground. Strips of meat hang from wooden frames, drying in the sun. On the beach a hunting party has just returned and Inuit are passing around small squares of thick Narwhal skin, a delicacy called Muktak.
This is a scene that has been played out for thousands of years. And it was a scene that we filmed earlier this year in August 2012.
"Our high tide is higher than we've ever seen it .... The shacks we live in never used to be reached by the waves but now we have to move them further inland."
- Jaloo Kiguktak, a resident of the Canadian Arctic
But it is a scene that, before long, may disappear forever. And from Bangladesh to Amazonia that is a recurring 21st century story; climate change is changing the way people live.
Given that fact, why does it seem that the majority of the world's leaders do not care? Climate change was not even mentioned in the US presidential debates. And then, almost immediately, along came Perfect Storm Sandy to give us a hurricane-force reminder that the weather is acting up and perhaps we should take notice.
Meanwhile, media coverage of climate change has crashed. In the years since the false hopes of Copenhagen in 2009, it has simply gone off the agenda. But that has got to change. Hold the front page - weird stuff is happening! And whether you believe mankind is responsible or not, it is affecting us all.
The natural order
When we filmed in the Arctic this summer, I met Mads Ole Kristiansen, one of a continuous line of Inuit hunters going back generations. We filmed him tossing bloody hunks of seal meat to his baying sled dogs.
"Without my dogs, I am nothing," Mads said. "Without his dogs, the hunter is nothing."
But this Spring, Mads had to shoot four of his dogs because the sea ice melted so early that he was unable to hunt for food.
This is a man who knows and understands the environment that provides his livelihood. And he is noticing change - big change.
|In the lead-up to COP18 negotiations in Doha, join the debate as experts discuss solutions to global warming
He gestured high above his head to demonstrate how deep into the ice he used to have to dig to hunt seal.
"And now, just 10 years later?" I asked.
He measured from the ground to his hip.
The natural cycles of the Arctic seem to be changing, and fast. There are reports of mosquitos being seen further north than ever before and sightings of birds that the locals do not recognise - red-breasted Robins for example.
We sailed across Baffin Bay and made landfall in Grise Fjord in the Canadian Arctic. Here we found a community aware that their beach is not as big as it once was.
"Our high tide is higher than we've ever seen it," said resident Jaloo Kiguktak. "The shacks we live in never used to be reached by the waves but now we have to move them further inland."
So how does that affect the man in Manhattan or in countless cities around the world where global warming seems a distant irrelevance?
Well, the Arctic is a global weather-maker. Mess with that and who knows what will happen? Sea-level rises are already being encountered around the world. It is possible they could reach catastrophic levels, which might just take a city dweller's focus away from the daily bagel - to say nothing of warming ocean currents being stopped in their tracks, the resulting desertification, the impact on food supplies and, not least, the very security of nations.
It has happened before
The Earth's cycles have seen countless ice ages and thaws, warming and coolings. Check out the New Scientist’s fascinating article and you will see how just 120,000 years ago, a blink of an eye in the scheme of things, ice covered a large percentage of the planet. Sea levels were 120 metres lower than they are now.
Then came the thaw, just 20,000 years ago.
And this coincided with mankind beginning to settle in warmer climes where small agricultural communities were formed. Indeed you could say global warming made us who we are today.
The difference this time is the rate of change; temperatures are climbing so rapidly that most scientists now agree mankind is at least partly responsible for what is taking place. And therefore something has to be done.
Which brings us to the latest Climate Change Conference, COP18, taking place in Doha. From Copenhagen to Cancun and Durban, all that has been achieved has pretty much been an agreement to meet again the following year.
And this time around, there is already a sense of resignation that this will be yet another talking shop - where delegates, environmentalists and politicians will speak that impenetrable climate language of CO2 sequestration, anthropogenic (human) interference and carbon offsets and credits. And make little progress.
In Qatar, an enormous convention centre has been prepared. The venue has more than 120 meeting areas. In addition there are two vast halls which will house 2,000 delegates each and 5,000 staff will be on duty round-the-clock.
In total there will be 17,000 delegates from 194 nations.
On the tiny island of Qerqetat way up in the Far North, they will not much care about COP18. But COP18 needs to care about Qerqetat and the thousands of communities like it around the world that are on the front line of global warming.
Think of that blue speck - our home. It is the only one we have.