Alice follows a trail of clues from ancient human bones, to studies of remarkable people living in the most inhospitable parts of the planet, to the frontiers of genetic research to discover if we are still evolving – and where we might be heading.

While much of the projected growth in human population is likely to come from the developing world, it is the lifestyle enjoyed by many in the West that has the most impact on the planet. Some experts claim that in the UK consumers use as much as two and a half times their fair share of Earth’s resources.

Marcus meets some remarkable individuals – Tommy, an obsessive artist who uses his whole house as his canvas; Derek: blind, autistic, and a pianist with apparently prodigious gifts; Claire who is also blind, but whose brain has learnt to see using sound.

He interviews scientists and campaigners from both sides of the climate change debate, and travels to New York to meet Tony, who has HIV but doesn’t believe that that the virus is responsible for AIDS.

This is a passionate defence of the importance of scientific evidence and the power of experiment, and a look at what scientists themselves need to do to earn trust in controversial areas of science in the 21st century.

He follows moment by moment how the earthquake was generated under the Pacific Ocean, travelled to the Japanese mainland, and the rare conditions that unleashed a tsunami.

Antarctica holds approximately 90 per cent of the world’s ice and has been measured to be at least 7,000 feet thick. If all of the Antarctic ice melted, sea levels around the world would rise about 200 feet. But the average temperature in Antarctica is -37°C, so the ice there is in no danger of melting. In fact in most parts of the continent it never gets above freezing.

The Arctic contains much less ice and most of it floats on the Arctic Ocean, the world’s smallest ocean (about eight per cent the size of the Pacific Ocean). Unlike Antarctica, people live here with the farthest northern city in the world being Norlisk, Russia, home to an estimated 230,000 hearty souls.

In 1995 the Intergovernmental Panel on Climate Change issued a report which contained various projections of the sea level change by the year 2100. They estimate that the sea will rise 20 inches with the lowest estimates at six inches and the highest at 37 inches. The rise will come from thermal expansion of the ocean and from melting glaciers and ice sheets.