Greetings and welcome to course two of Arctic climate environment and the geographies of the changing north. I'm your host Mark Soares. I'm with the department of geography at the University of Colorado, Boulder and also with the Cooperative Institute for research and environmental Sciences. Well, what's course two all about? It's all about the changing Arctic past, present and future. Now in course one. We got a broad overview of the Arctic as a system. What is the Arctic in terms of geographic bound? How do we define the Arctic? Who are the peoples of the Arctic? What was the early exploration of the Arctic, later exploration? How did we build our knowledge? And then remember we got into issues of basic patterns of things like temperature and precipitation and cloud cover. We talked about permafrost in the Greenland ice sheet. Now throughout all of that discussion on course one. We touched upon the issue of the rapidly changing Arctic, but what we're going to do in this course is really dig into that. Really start to dig into the nitty gritty of the changing Arctic past, present and future. Now, like course one, this five modules in this particular class and the first one is key indicators of change. What are these big indicators of change that we see in the Arctic? Is visible signs of change? Well, certainly the shrinking of the Arctic sea ice covers rapidly shrinking, notably in summer, something like 13% per decade in September. It's pretty astounding, Arctic amplification of recent warming. The Arctic as a whole is warming at twice the rate of the globe is a whole. Bigger than that, in some regions in some seasoned, something we long expected but here it is warming and thawing permafrost. Remember, permafrost is perennially frozen ground in the Arctic. And what we're seeing across the Arctic is that permafrost is warming, and in some places is thawing. Tremendous impacts on landscapes and infrastructure and the issue of coastal erosion. That'd be cart, in part because we are losing the sea ice cover in part because a warmer ocean waters, number of factors. Were seeing extreme coastal erosion along parts of the Arctic and it's really a problem for some people. For example, the village of Shishmaref had to move because it was literally being walked into the sea. In module two, we will start to focus on the shrinking land ice. We're going to talk about sea level rise and how the Arctic and the melt of Arctic glaciers and ice caps and the Greenland ice sheet, one of our planet stewie sheets. The other in the Antarctic ice sheet, are all melting down on contributing to global sea level rise. But will also learn how complex the processes are on the Greenland ice sheet, where we have to consider the surface mass balance. We have to consider what we call the dynamic mass balance, that relates to icebergs being calved into the Arctic Ocean. And then I'm going to turn to a little bit of a personal story about the death of the Saint Patrick Day ice caps. These are two little ice caps that I study as a young graduate student, starting my first field season in the Arctic way back in 1982. And now we find out that they're gone, they're dead. These ice caps have died even over the course of a fairly short research careers. We can see the death of these ice caps. That gives you an indicator of how rapidly the Arctic seems to be changing. Module three, cascading impacts of a warming Arctic. It's not just the loss of sea ice, is not just the rise in temperature, it's not just the warming and thawing of the permafrost. That there are cascading impacts of these change, such as Arctic amplification in mid latitude whether. This evidence out there that the strong warming of the Arctic influence jet stream patterns aloft. And could influence weather patterns all the way down into middle latitudes. Controversial, but it's a big area of study. Extreme weather events in the Arctic, boy, we've seen some crazy stuff in recent years, just remarkable heat waves. For example, where we had conditions at the north pole get to the melting point on new years or the day before new years back close at 2015. And we've had some more recent events as well. Extreme warming over Siberia, for example, 100 degree temperatures in Berkeley and Scott in Russia. And Arctic change in terrestrial ecology and Arctic change in marine ecology, the very landscape of the Arctic is changing. Treeless, windswept, tundra being transitioned into shrubs and trees. Marine ecology affect going right through the food chain. And we're seeing, for example, fish species that have not been seen before in the Arctic now coming into the Arctic. With regard to the lands were seeing a species like moose start to move into the Arctic, where we didn't see them before because they find it a more habitable environment. Yet there are other species like karabo not doing so well right? And this is a big issue with Arctic change, as it is for the rest of the world. There are winners and there are losers. Module four learning from the past, to understand where the Arctic is today and where the Arctic can be going. It is very valuable to understand past claims. What was happening in the Arctic before the era of instrumental record? So we're going to learn all about that, the study of paleoclimatology. We're going to talk about the data sources. How we use these different types of data to try and reconstruct past climate. Then we're going to focus on the climate of the past, previous million years. Great Ice age is an interglacials and how the Arctic plays into this and then look at the Holocene, that's the age we live in now, the recent period. Although there's some people that say we've moved into another period now called the Anthropocene, the age of humanity, will see. Then in module 5, we're actually going to look at projections of the future Arctic. We're going to take a look at climate models, what climate models are all about? And the real value in the power of climate models, to tell us what we could be expecting the future in terms of patterns of Arctic, temperature of Arctic precipitation. The fate of the sea ice cover in something called the permafrost carbon feedback. These models are very, very powerful, but they have their own problems and they're not perfect in there are many uncertainties ahead of us. And I'll try and emphasize some of those uncertainties as we go along. So I hope you enjoy this class. I've certainly enjoyed putting it together and I think we're going to have a lot of fun. Thank you.