The human causes of climate change fall into two categories: proximate causes and driving forces. Proximate causes are the human activities that directly cause climate change. There are two overarching categories of proximate causes: land transformation and industrial processes. People transform the land surface in many ways, with some important types being deforestation, agriculture, urbanization, mining, reservoir building, land draining, and transportation network building. Industrial processes include energy production, transportation, manufacturing, construction, waste disposal, petrochemical, mineral, and food processing, and many other activities. All of these activities change the flux of energy and mass to the climate system.
Driving forces of climate change are complex, interactive actions and rationales that give rise to proximate causes. In other words, driving forces are the underlying reasons why people engage in various activities. There are five driving forces: population growth, technological development, economic growth, institutions, and attitudes and beliefs. Understanding the driving forces helps to answer questions such as, why do people drive cars to work (a proximate cause of climate change) when they could walk, ride a bike, or take a bus?
Lesson 2 of this course looks more deeply into proximate causes and driving forces. It also gives some background on greenhouse gas emissions and mitigation, thereby setting up the succeeding lessons on energy emissions and mitigation, transportation emissions and mitigation, local emissions and mitigation, and climate policy.