Human Dimensions of Global Warming



For this lesson, we'll explore two of the most vulnerable environments to climate change impacts - the coasts and cities.

Scientists have little doubt that the impacts and costs of climate change will be unavoidable –– and most likely the greatest –– in coastal environs. More people and more infrastructure will suffer harm in coastal zones than in any other place on Earth. Most other aspects of climate change are only now starting to be felt, but impacts in coastal zones are readily apparent today and accelerating. In response to this unfolding disaster, many of the world’s great coastal cities are already developing adaptation strategies and hoping to avoid the human and financial tragedy that awaits them.

About half the world’s population currently lives in cities. An increasingly larger proportion of the population will live in cities at the same time that climate change intensifies. About 85 percent of the Western Hemisphere’s population will be living in cities by 2030, up from somewhere near 50 percent in the middle of the 20th century. Even more shocking urban growth has taken place in Asia and Africa, going from 17 and 15 percent urban in 1950 to a projected 54 and 51 percent in 2030, respectively. Estimates are that more than 37 percent of the world’s population will live in cities with populations larger than 1 million people in 2030. Against this backdrop of unprecedented urban growth, this lesson will explore relationships between cities and climate change.

Climate-City Relationships

Many people mistakenly think that cities have no connection with climate because urban dwellers’ homes and vehicles insulate them from direct contact with it. Climate, however, is intimately linked to cities and their inhabitants. Many urban activities are climate sensitive, including such diverse activities as basic water use, transportation, construction, and sport and recreation. Climate also affects the costs of climate control, causing urbanites in tropical and subtropical climates to expend huge amounts of energy and money on air conditioning, whereas city dwellers in extratropical climates spend vast sums on heating in winter. Climate and weather also interact with socioeconomic and other natural stresses to increase or decrease overall stress on urban inhabitants.

Climate-city relationships therefore significantly influence the way that cities function, so if these interactions change because climate changes, cities must adapt to accommodate the new climate. Consequently, understanding the likely impacts of climate change on cities, the vulnerability of cities to those impacts, and the potential of cities for adaptation to climate change is a vital area of study because of the enormous number of people who live in cities.

Urban Indicators
Year Percentage Urban Percent of the world's urban population living in the region Percent of urban population in different size-class of urban centre, 2000
1950 1975 2000 2030* 1950 1975 2000 2030* Under 0.5 m 0.5 - 1 m 1 - 5 m 5 - 10 m 10 m+
Northern America 63.9 73.9 79.1 86.7 15.0 11.9 8.8 7.1 37.4 11.0 34.3 5.4 11.9
Latin America and the Caribbean 42.0 61.2 75.4 84.3 9.6 13.0 13.9 12.4 49.8 9.0 21.7 4.9 14.7
Oceania 62.0 71.5 70.5 73.8 1.1 1.0 0.8 0.6 41.9 0.0 58.1 0.0 0.0
Asia 16.8 24.0 37.1 54.1 32.0 37.9; 47.9 53.7 49.0 10.0 22.6 8.8 9.7
Africa 14.7 25.4 36.2 50.7 4.5 7.0 10.3 15.1 60.2 9.6 22.1 4.6 3.5
WORLD 29.0 37.2 46.8 59.9 100.0 100.0 100.0 100.0 52.6 9.8 22.4 6.8 8.4

What will we learn?

This lesson is a bit unique in that we are tackling two separate but decidedly related issues - impacts of climate change on our coasts and impacts of climate change on our cities.  Not all cities are near water, but many of our largest, busiest, most populated cities are.  Therefore, it makes sense to think about these issues in tandem while also recognizing their unique attributes.

By the end of this lesson, you should be able to:

  • describe the main physical impacts of climate change on coasts and in cities (including urban utilities and infrastructure, industry, services, and social systems);
  • describe which people and what things are exposed to these physical impacts;
  • explain why these exposed people and things are or are not sensitive to these physical impacts;
  • explain the adaptive capacity or lack of adaptive capacity of coastal communities;
  • discuss the costs of adaptation versus the costs of inaction;
  • explain how location, size, and type of economy affect the overall vulnerability of a city to climate change;
  • describe four factors that influence the adaptive capacity of cities in relation to climate change and explain how those factors work;
  • recognize and correct the three problems of wordy sentences.

What is due for Lesson 9?

Lesson 9 will take us one week to complete. Please refer to the Calendar in Canvas for specific time frames and due dates. Specific directions for the assignments below can be found within this lesson.

Complete the following steps to complete Lesson 9:

  • Work through Lesson 9 in this web site.
  • Complete the Required Reading Assignments.
  • Complete the Writing Symposium Quiz in Canvas.
  • Complete your Our Climate Stories in Canvas.
  • Complete the Lesson 9 Reading Reflections in Canvas.
  • Begin working on Unit 3 Exam in Canvas. Read through the essay questions to begin thinking about the responses you will compose next week during the Exam week.
  • Begin working on Unit 3 Reflection in Canvas. Read through the reflection prompt to beging thinking about the response you will compose next week during the Exam week.


If you have questions, please feel free to post them to the Ask a Question about Lesson 9 forum. While you are there, feel free to post your own responses if you, too, are able to help a classmate.