Lewis Pugh was born in Plymouth, England, the son of a navy officer. At the age of 10, his family emigrated to Cape Town, South Africa. Although he lived within sight of the ocean, it was only at the age of 17 that he learnt to swim. One month later, he swam 12 km from Robben Island (where Nelson Mandela was imprisoned) to Cape Town. By the time he entered maritime law, his fascination with swimming had already got the better of him.
Since then Lewis has pioneered more swims around famous landmarks than any other swimmer in history. He is also the first person to complete a long distance swim in all five oceans of the world (Atlantic, Indian, Pacific, Arctic and Southern).
Nowadays, he swims to highlight climate change. He is most famous for his swim at the North Pole in 2007, which coincided with the lowest coverage of Arctic sea ice ever recorded. He also spends much of his time public speaking and lobbying world leaders to protect the environment.
How did you get the idea of swimming for the environment?
It was a progressive thing. I had done swims all over the world. I had been swimming in places that were so environmentally sensitive, that there came a time that I felt I had to talk about these issues.
Through my swims I've had a unique perspective on climate change. I have witnessed retreating glaciers, decreasing sea ice, coral bleaching, severe droughts, and the migration of animals to colder climates.
As a result of these experiences I became determined to do my bit to raise awareness about the fragility of our environment and to encourage everyone to take action.
Why do you campaign on behalf of climate change and not for water. After all, water is your element?
I think climate change is the biggest issue. It will affect everything. It will affect water supply, security, health care, migration of people and animals. It is the biggest issue that ever faced humans.
With the current pace of sea ice melting, climate change threatens world peace, economic stability and our way of life across the globe. I don't think this. I know this.
I think if you are going to dedicate your life to an issue, it has to be a big issue.
What came first: the desire to swim or to save the environment?
I actually started off as a lawyer. After studying law at the University of Cape Town and the University of Cambridge, I became a maritime lawyer in London. Then I became a swimmer. And now I see myself as an environmental campaigner. My life is continuously changing.
What was your first thought after you finished your arctic swim?
I was just so happy that I was alive. It was an extreme swim. I couldn't feel my hands for another four months. It pushed me right to the limit.
I am acclimatized to the cold having spent many years in cold places. As soon as I enter cold water my body shunts all my warm blood to my core to protect my vital organs. It then generates incredible heat. Before I even enter the water, I am able to elevate my core body temperature by as much as 1.4°C (2.5°F). This phenomenon, now known as "anticipatory thermogenises", has to our knowledge not been noted in any other human being.
I also put on a tremendous amount of weight before swimming in a polar region. It makes sense, I have never seen a thin animal in a polar region! Walruses, seals and polar bears all have a good layer of insulation.
Were you frightened during the swim? Did you have any time to think of anything while you are swimming?
You have to think about what you should be thinking about. It is the most important thing you can do. If you let your mind move and start to think about the cold... you are finished.
Most of your swims are in cold water! Do you prefer cold water to warm?
No. I prefer warm water. Anyone who likes the cold has never been properly cold. It just so happened I was better able to highlight climate change in cold places.
The temperature of the sea varies hugely. For example the water off the Maldives is gorgeous at around 30 degrees Celcius. In summer, the English Channel is refreshing – around 17 degrees Celcius. However, the North Pole is another world. The water ranges between 0 and minus 1.8 degrees Celcius. When I swam at the North Pole the water was minus 1.7 degrees. The swim took 18 minutes and 50 seconds to complete. It was, by far, the hardest swim I have undertaken!
However, the press will never follow a story unless there's extreme hardship involved.
Do you use Vaseline or oil?
No. I swim according to the rules of the Channel Swimming Association. They only permit a swimming costume, a cap and a pair of goggles.
By doing this, I am also making a statement. I meet politicians and ask them to enact laws to cut our carbon emissions and protect the environment. These measures are often unpopular with their electorate and require courage and foresight. If I am asking world leaders to be courageous, I must also be courageous.
On your website you say: "Forget about future generations. This is about us." Can you really do this?
When I was born the world's population was 3.5 billion people, we are now 6.6 billion we will be 9 billion by 2050. This is in my lifetime!
There are people now who are talking about linking climate change to population growth. And obviously India is up in arms about this debate.
And aren't the Chinese allowing families to have more children?
Not quite. In industrialised areas the rule is still only one child per family. Outside of these areas the rule is not implied. So 55% of families can have more than one child. But the Chinese will tell you that the one child per family policy has cut more carbon than any other policy. They would say, don't come to us and tell us about cutting carbon emissions.
At the moment, I can't think beyond December and Copenhagen. We have the Europeans blaming America. We have America blaming India and China. We have the developing nations blaming the west. We are all blaming each other without a bit of self inspection. My dream is that everyone forgets about what everyone else is doing and looks at what they are doing and just says what can I do now to ensure that my children and grandchildren have a future.
What is your next project?
A swim in the Himalayas. I think as environmental campaigners we always have to be one step ahead of the public and two steps ahead of the journalists and indentify places that are under threat. And for me the next big battle ground will be in the Himalayas.
So in April 2010, I will be undertaking a swim in a glacial lake under the summit of Mount Everest. As a result of global warming, temperatures in the Himalayas have risen by 1 degree Celsius and glaciers in the Himalayas are receding faster than in any other part of the world. Scientists predict they could disappear within 25 years.
These glaciers are not just ice. They are a lifeline – they provide water to a fifth of the world's population.
How long will you keep swimming for the environment? And do you think you will see environmental improvement by the time you are 70?
I will swim until my last day! Let me give you an example. When I grew up in Cape Town, I hardly ever saw any whales. Then they enacted a law in the southern oceans to protect several species of whale. And now when you are there you see whales jumping... jumping. There are things that we can do that will make a huge difference.
I dream of a day when we will have alternative energy supplies, which is the key to protecting the environment.