Climate Change: The Science Behind the Crisis - Part 1

This course focuses on the scientific background of the present-day climate crisis, often also called Global Warming. The course will give you the scientific knowledge and tools needed to understand the crisis, including the many uncertainties behind the science. What do we really know with great certainty, and what is less certain? Can we still act given the uncertainty in the science behind the climate crisis? After a short introduction to global warming, we will go back in time and put the present changes occurring today in context, by looking back in time to the ice ages that have occurred on our planet over the past million years. Are the changes happening today really that unusual? Have similar changes occurred in the past? We will then focus our weekly discussions on key aspects of the climate system to better understand the complexity of our climate. We will take a journey to our Sun, the source of all our energy in the climate system. Can the changes in our Sun explain the recent global warming? We will discuss the Energy Balance of our planet resulting from the balance between the energy we get from the Sun, and the energy lost from the Earth by cooling. We will learn about the water cycle and the important role of clouds and rain in the climate system. How do clouds impact the Earth’s temperature? We will discuss atmospheric circulation patterns, winds and storms. 3b

• Introduction : An overview of the topic of global warming and climate change. A brief introduction to the story behind the climate crisis and the implications for the future.
• Paleoclimate : A look back in time to our past climates on Earth. What can we learn from the past about the future? What caused the ice ages?
• Our Sun : The Sun drives the Earth’s climate, the weather. However, our Sun has its own variability on many time scales that can impact the Earth’s climate. Can changes on the Sun explain global warming?
• Earth's Energy Balance : The Earth’s temperature is related to the energy balance of our planet. This delicate balance is between the energy received from the Sun (warming) and that lost by the Earth (cooling).
• The Water Cycle : More important than temperatures for life on our planet, is water. And our fresh water needed for drinking and irrigation is related to the Hydrological Cycle.
• Clouds : The temperature of the Earth is strongly dependent on the clouds in the sky. Clouds have a net cooling effect on the Earth’s temperature, and we are not sure if rising greenhouse gases will increase or decrease clouds in the future.
• Atmospheric Motion : Another important part of the climate system is the motion of air both vertically and horizontally in our atmosphere. The motion of air results in winds, storms and clouds, and also defines the locations of our rainforests and deserts.