 Last week we briefly looked at the many lines of evidence that humans are causing global warming. We also looked at how all this evidence has resulted in an overwhelming scientific consensus. However, a small minority don't even accept that global warming is happening. So this week we're going back to basics. We'll examine the many different indicators that our planet is warming. We'll look at the heat building up in our climate system and how that affects heat records and sea level rise. We'll look at a growing contributor to sea level rise, melting ice. We'll talk about the challenges of putting together a global temperature record and we'll even look at what's been causing some recent intense winters in the northern hemisphere. I'm here at the University of Ottawa where one of our presenters is researching the cryosphere. Standing in the snow, it might seem a little weird talking about global warming. But remember, global warming is about the temperature averaged over the whole planet. Even while the planet continues to build up heat, some places will still experience cold. So let's look at some of the myths casting doubt on the basic reality of global warming.