Keynote on "climate change - state of the science"

We are in the midst of a major global warming, as witnessed not just by temperature measurements, but also for example by the record loss of Arctic sea ice in recent years. In the year 2008, both the Northwest Passage and the Northeast Passage in the Arctic were open for ships to pass through for the first time in living memory. Satellite data show that the huge ice sheets in Greenland and Antarctica are losing mass at an accelerating pace. What are the causes of this warming? How much warming must we expect in future? How does it affect sea level, extreme events and other aspects of the climate system? And can we stop this warming, and how? These topics will be discussed based on the most recent data and climate simulations.