TEHRAN - A couple who had set on a bicycle ride from southern Vietnam in February 2015 to raise awareness about consequences of climate change arrived in Tehran last week.

Simon Nelson, 41, from Scotland, and his 27-year-old Vietnamese wife Nguyen Thi Kim Ngan explained about the purpose of their trip in a press conference in the embassy of the Socialist Republic of Vietnam in Tehran on Sunday.

Simon, an expert in geography, said “further increases in temperature will turn the whole of Iran along with most of the world into desert.”

The text of Simon’s speech at the conference reads as below:

I have been concerned about climate change ever since I studied it at university more than 20 years ago. And I have been campaigning to stop it ever since then. I've handed out leaflets, signed petitions, occupied a tree at road protests and chained myself to power station. First in the UK, then Australia and most recently in Vietnam I have been volunteering for 350. 350 is an international climate change organization campaigning to stop climate change.

At around the same time I started campaigning against Climate Change the politicians started talking about solving the problem. Over those 20 years they have achieved absolutely nothing. Concentrations of greenhouse gases are still rising. This year they are meeting again in Paris in November. But time is running out. Unless massive cuts are made to emissions of greenhouse gases beginning almost immediately climate change will become unstoppable and temperatures will rise by 4 or even 6 degrees this century. Those kinds of temperatures increases are simply not compatible with the continuation of human civilization or indeed most of life on earth. The sea will swamp many of the most important cities in the world, storms and droughts will become more severe but most importantly of all much of the world will turn to desert and large areas will become too hot and too dry to grow enough food.

Vietnam and Iran have many things in common; kind hearted and friendly people, a love of food and a culture that recognizes the importance of family. But they have another unfortunate characteristic in common. They are both at incredible risk from Climate Change - but for different reasons. Vietnam has a very long coastline and many areas are very low lying. Nearly 70% of the biggest city - Ho Chi Minh is less than 2m above sea level and the most important agricultural area the Mekong Delta is even lower. With sea levels projected to rise by between 1 and 2 meters this century the country faces an uncertain future.

In Vietnam the problem is too much water. In Iran as you know the opposite is true. Already arid it will become more so as the climate warms. Many areas will receive less rainfall and as temperatures increase evaporation rates will also rise. Iran is already drawing ground water at an unsustainable rate. Within 50 years aquifers in 12 provinces are projected to run dry. Without urgent action to stop climate change in as short a time frame as 30 to 40 years many areas of Iran could become uninhabitable desert.

That is why we are riding from Vietnam to Paris. In December the United Nations Climate Change conference will meet. World leaders will discuss an agreement to limit the emissions of greenhouse gases. Yet currently the promises made by governments are nowhere near enough to stop it. Less than half of what is necessary to limit climate change to 2C.

The threat we face is big so I wanted to do something big that would convey the urgency of the situation and cycling 16,000 km is pretty big. I thought that people might think if those guys are willing to cycle so far maybe I should do something. Also because I love riding my bicycle so it's important to combine your passions.

Along the way we have been sharing the story of our trip; speaking at schools, discussing with the people that we meet and talking with the media. Our message is that if we want a future for our children, if we want to preserve the planet then everyone needs to take part in the campaign to stop climate change. I hope that this year you will join the movement that is spreading across the globe. Together we can save the world.

Highlight: Our message is that if we want a future for our children, if we want to preserve the planet then everyone needs to take part in the campaign to stop climate change.