Lesson 10 Summary

In this lesson, we looked at the potential impacts of projected climate change on civilization and our environment. The key points are as follows.

• Adaptation and mitigation are two often-discussed strategies for dealing with the threats and challenges of human-caused climate change. The two approaches are not mutually exclusive —it is very likely that both will need to be employed if we are to limit societal vulnerability to climate change.
• Adaptive measures to reduce coastal vulnerability to sea level rise take the form of three progressively more defensive responses to increasing magnitudes of sea level rise — protection through engineering, followed by accommodation to rising sea level and, eventually, managed retreat.
• There are a variety of adaptive responses that might be taken to deal with shifting water resources resulting from anthropogenic climate change. These responses take the form of demand side and supply side actions. On the demand side are better conservation of available freshwater resources (a so-called no regrets strategy), and introduction of a system of tradable water rights to help insure efficient use of available fresh water. On the supply side are the development of better distribution systems to move water from regions of surplus to regions of deficit, better use of available groundwater and freshwater aquifers, and (though currently not cost-effective) the use of desalinization technology, particularly in coastal regions where distribution requirements would be minimized.
• Adaptation can to some extent mitigate the loss of agricultural productivity due to climate change, though there are substantial differences between tropical and extra-tropical regions, and also between different crops (e.g., staple cereal crops such as rice, wheat, and corn/maize).
• Theoretical crop models subject to admittedly limited (and perhaps not wholly realistic) climate change scenarios of, e.g., simple warming of temperatures and elevation of CO₂ levels, indicate that for moderate warming, losses in tropical regions can be mitigated through the introduction of appropriate adaptive measures. Adaptive measures can further bolster agricultural increases in extratropical regions that benefit from longer-growing seasons with warming.
• The same crop models indicate that as the warming progresses, gains in the extra-tropical regions become increasingly less, and losses in the tropical regions become increasingly greater, even with appropriate adaptive measures. As warming approaches 5 °C, losses are seen in all regions regardless of adaptation, and both global food productivity declines and global food price increases become substantial.

Reminder - Complete all of the lesson tasks!

You have finished Lesson 10. Double-check the list of requirements on the first page of this lesson to make sure you have completed all of the activities listed there before beginning the next lesson.