Teaching Essential Principle Seven

Climate change will have consequences for the Earth system and human lives.

Teaching this principle is supported by six key concepts.

Click here to see them.

  1. Melting of ice sheets and glaciers, combined with the thermal expansion of seawater as the oceans warm, is causing sea level to rise. Seawater is beginning to move onto low-lying land, contaminating coastal fresh water sources, and gradually submerging coastal facilities and barrier islands. Sea-level rise increases the risk of damage to homes and buildings from storm surges such as those that accompany hurricanes.
  2. Climate plays an important role in the global distribution of freshwater resources. Changing precipitation patterns and temperature conditions will alter the distribution and availability of freshwater resources, reducing reliable access to water for many people and their crops. Winter snowpack and mountain glaciers that provide water for human use are declining as a result of global warming.
  3. Incidents of extreme weather are projected to increase as a result of climate change. Many locations will see a substantial increase in the number of heat waves they experience per year and a likely decrease in episodes of severe cold. Precipitation events are expected to become less frequent but more intense in many areas, and droughts will be more frequent and severe in areas where average precipitation is projected to decrease.
  4. The chemistry of ocean water is changed by absorption of carbon dioxide from the atmosphere. Increasing carbon dioxide levels in the atmosphere are causing ocean water to become more acidic, threatening the survival of shell-building marine species and the entire food web of which they are a part.
  5. Ecosystems on land and in the ocean have been and will continue to be disturbed by climate change. Animals, plants, bacteria, and viruses will migrate to new areas with favorable climate conditions. Infectious diseases and certain species will be able to invade areas that they did not previously inhabit.
  6. Human health and mortality rates will be affected to different degrees in specific regions of the world as a result of climate change. Although cold-related deaths are predicted to decrease, other risks are predicted to rise. The incidence and geographical range of climate-sensitive infectious diseases— such as malaria, dengue fever, and tick-borne diseases—will increase. Drought-reduced crop yields, degraded air and water quality, and increased hazards in coastal and low-lying areas will contribute to unhealthy conditions, particularly for the most vulnerable populations.

What does this principle mean?

This principle relates to the current and predicted consequences of climate change. Once primarily the domain of climate scientists, the impacts of climate change on humans and environmental systems have become a focus for resource managers, medical professionals, emergency managers, insurance companies, and military planners. A great challenge of the 21st century will be to prepare communities to adapt to climate change while reducing human impacts on the climate system (known as mitigation). Additional factors such as poverty, a lack of resources, the absence of political will, and the necessity for nations to work together add further complexity to this challenge. Many jobs if not entire industries will be affected by the changes that are happening or are anticipated for the future.

Victory Garden

Why is it important?

The importance of this principle is readily apparent: our world is changing, the degree of changes is projected to increase, and many of the consequences will create hardship for humans. Some key points are:

  • The impacts of human-caused climate change are already being seen, from polar regions, to our backyards, to communities around the world.
  • Consequences of climate change will affect the biosphere on many levels, from coral bleaching, to dying forests, to species extinction.
  • Human infrastructure is threatened by a changing climate, such as encroachment of coastlines, stress to the energy grid, and shifting structures as a result of melting permafrost.
  • A warming climate threatens mountain snowpacks, fresh water supplies and hydropower that serve millions of people.
  • Changes in climate and precipitation patterns will impact agriculture and food security.
  • Populations that are already vulnerable in terms of sea level rise and food security are poised for the greatest hardships. Political unrest, migration of refugees and global economic impacts are all possible outcomes.

Muir Glacier Comparison
Photographs of the Muir Glacier taken in 1941 and 2004 showing the retreat of the glacier. These photographs are from the National Snow and Ice Data Center's repeat photography project.

What makes this principle challenging to teach?

Alarming students and the public about the impact of climate hazards, such as droughts and extreme events, can be counter-productive and cause people to ignore the warnings or succumb to denial. However, just glossing over the severity of the impacts and the enormous social and environmental ramifications of climate change can lead to a society that is ill-prepared to deal with change. Finding a balanced approach and avoiding a "despair deficit" is clearly a good practice, both inside and outside of the classroom.

Another challenge for fostering public awareness for the consequences of climate change is that many of the impacts are far away and may not directly touch the lives of our students. Two solutions to this are to use local data to examine climate changes that affect your region, or to employ a case study approach that will allow students to gain a deeper sense of how these impacts will profoundly re-shape people and ecosystems in faraway areas.

How can I use this principle in my teaching?

There are many ways to illustrate impacts of climate change. The scale of impacts ranges from global to local, while the nature of these impacts can affect humans, plants, animals and ecosystems.

Integrating Solutions

This is a key area to incorporate solutions into one's pedagogic approach. It can be very easy for students to succumb to despair over the world's problems. Some possibilities include:

  • Drawing on case studies showing successful emissions reduction strategies.
  • Examining adaptation strategies for humans, plants and animals.
  • Creating an atmosphere of creativity and problem-solving as we all strive to meet this grand challenge.
  • Middle school students are more likely to be familiar with impacts of climate change on animal habitats, such as those of polar bears and penguins. This can be an opportunity to examine impacts of climate change on human populations as a result of sea level rise, for example. See the activity Impacts of Topography on Sea Level Change.
  • In high school, students can investigate climate change impacts within a number of traditional courses such as geography (to examine sea level rise), biology (to consider species' adaptive strategies) or chemistry (to study the effects of increased carbon dioxide in ocean water, as illustrated by Off Base - Acidity of oceans). In courses such as social studies, students can use case studies to examine the effects of climate change in other cultures, such as polar regions or island nations.
  • In the introductory undergraduate curriculum, students can use a technology-based approach to study climate effects worldwide. By employing tools such as blogs, Google Earth and the websites of research and governmental agencies, students can examine faraway effects of a changing climate. (for example, see Google Earth Tours of Glacial Change)
  • Upper-level college students can engage in research about specific types of impacts, such as projections of future sea level rise, sea ice melt or increases in hurricane intensity. (example Exploring the Link between Hurricanes and Climate using GCM Results)

Credit: CLEAN