The Earth’s Energy Balance and Factors that Cause Climate Change

The Physics of Climate Change

In this course, Professor Joanna Haigh (Imperial College London) discusses the physics behind climate change. In the first mini-lecture, we explore the Earth’s energy balance, the physical processes in the Earth’s atmosphere that have contributed to global warming, and other factors that cause climate to change. In the second mini-lecture, we discuss how atmospheric carbon dioxide has changed over various time scales and introduce some physics that help us study the climate and predict its future. The third mini-lecture considers more factors that have influenced climate and their current impacts on temperature, ice, and sea level. The fourth mini-lecture discusses the future potential impacts of climate change and outlines two models that predict the best and worst case scenarios of climate change from now until 2021. In the fifth mini-lecture, we introduce some of the international organisations and agreements that have been made in response to climate change. In the sixth mini-lecture, we consider percentages of emissions per country and per person per country, as well as emissions by source, and discuss future conferences and policies.

The Earth’s Energy Balance and Factors that Cause Climate Change

In the first mini-lecture, we discuss factors that cause climate change and the physical processes in the Earth’s atmosphere. In particular, we consider: (i) a plot of the Earth’s global surface temperature from the past 100 years that provides evidence for climate change; (ii) the Stefan-Boltzmann Law to understand the Earth’s warming; (iii) the greenhouse effect and how it improves our understanding of the Earth’s warming, which is essential in correctly calculating Earth’s surface temperature; (iv) natural and human factors that cause climate to change; (v) the gases in the atmosphere and which ones are greenhouse gases that contribute to global warming; (vi) the spectrum of heat radiation leaving the top of the atmosphere; and (vii) the infrared spectrum of the top of the atmosphere and the effect of each gas in this plot.