The Human Fingerprint explores the underlying science and evidence of climate change. From the badlands of Alberta to Peru and around the world, we examine clues to Earth's ever-changing climate to learn what today's changing temperatures may mean for our own futures.

Seeking answers to how climate has affected human lives, we explore a very different western Canadian climate where dinosaurs once thrived in tropical jungles. Just a tiny difference in average temperature can have profound effects... like the tiny drop in average temperature that triggered The Great Famine of the early 1300s, killing tens of thousands across northern Europe.

In a Vancouver Island forest, cycles of life and decay illustrate the carbon cycle... a cycle that is increasingly skittering out of control, as human activities release billions more tonnes of carbon and other greenhouse gases into Earth's atmosphere every year. This is the heritage of the Industrial Revolution, which has transformed our world. The Industrial Revolution is still happening in places like China, where millions of people are buying their first cars.

Travelling to Hawaii, we explore the link between powerful El Nino events and an increasingly energized atmosphere. In Toronto, we see how scientists project future climates with powerful computer simulations built on mind-boggling math. The scenarios they predict for 2050 - illustrated with morphing computer graphics - inevitably show a hotter, more extreme world.

The signs are already evident - in the "moving Madonna" of the Lousiana Gulf coast, the records of British amateur climate observers, the melting ice of Nunavut, the dying dogwoods of southern Ontario. But there are three major impacts of climate change that we cannot afford to ignore.

A hotter climate means more extremes - more storms, more droughts, more floods, more of the kind of weather that kills. And as temperatures climb, new diseases are emerging, as deadly microorganisms spread and jump species, moving into warming temperate zones.

Finally, the last - but most ominous - potential impact. Thousands of times in Earth's history, rising temperatures have culminated in sudden climate "crashes" - drops of up to fifteen degrees in just 10-20 years. Eminent scientist Dr. Wallace Broecker believes the cause lies in the North Atlantic, where the warm waters of the Gulf Stream slow and drop.

In the end, no one knows exactly what The Great Warming will bring in the decades to come -- but it has already delivered a powerful warning - Earth's temperature is rising at the fastest rate in recorded history, and our climate is changing.