 That concludes week three of Denier 101X. This week we explain how humans are increasing the amount of heat trapping greenhouse gases in the atmosphere. As a consequence, we're causing global warming. Gavin Corley and Andy Scoose explained how humans are increasing the amount of carbon dioxide in the atmosphere. Mark Richardson and Sarah Green explained how carbon dioxide is a greenhouse gas. What that means is greenhouse gases trap heat. With all this heat building up in our climate system, Dana Nechitelli, Mark Richardson and Sarah Green took us through the many human fingerprints being observed throughout our climate. These all add up to many independent lines of evidence, all pointing to the same conclusion. Humans are causing global warming. Next week we look back at the past and forward into the future. We'll start by looking at paleoclimate, the study of past climate. What does the Earth's past tell us about what we can expect in the future? We'll also look at what climate models can tell us about future climate change. Week four includes some exciting interviews with paleoclimatologists, scientists studying past climate change, and climate modelers. Now I don't want to play favorites, but well, a personal highlight for me was an interview with Dan Lunt from the University of Bristol. Dan created a climate model of middle earth, the world of the Hobbit and Lord of the Rings. So we created a special feature, the climate of middle earth. That ended up a little longer than our usual seven minute videos. So it seemed appropriate to divide the feature up into a trilogy. Part one will be available next week. I hope you enjoy our middle earth features as much as I have. And don't forget there are other lectures and interviews as well. So I hope you enjoyed week three of Denial 101X. As in past weeks, be sure to join the weekly wrap up discussion forum below and share what you learned this week, ask any questions you might have and let us know your thoughts about next week's topic, which is past and future climate change. So we look forward to reading your comments and seeing you again next week.