Summary and Final Tasks



Geoengineering is the deliberate manipulation of the earth’s atmosphere, with the objective of controlling the rate of warming or otherwise mitigating the rate of climatic change. Geoengineering options that would directly reduce the amount of radiation trapped within the atmosphere range from controlling emissions through the capture and long-term storage of greenhouse gasses in geologic formations to the deployment of satellites or other devices aimed at reflecting sunlight back into space. Geoengineering options that would affect the climate through modification of land and sea include reforestation and deploying chemicals in the ocean that would cause oceans to absorb greater amounts of radiation. Geoengineering is a controversial proposition, and geoengineering activities are not currently regulated by any major international agreements. There are two primary reasons for the controversy. First, with few exceptions, most geoengineering options exist only in theory or in the realm of science fiction. The exceptions (options with which we have some real-world experience) include cloud seeding and the injection of carbon dioxide into oil and gas wells to get even more oil and gas out. None of these applications of geoengineering technologies are related to climate change – they have been employed for short-term weather modification or to make fossil fuel production activities even more productive. Second, geoengineering is often perceived as a fix to the climate problem that can (might?) work when all other options have been exhausted. The “bathtub” analogy of the greenhouse effect tells us that most geoengineering options alone will not be sufficient to reverse or mitigate any ill effects from climate change.

Reminder - Complete all of the Module 9 tasks!

You have reached the end of Module 9! Double-check the Module Roadmap to make sure you have completed all of the activities listed there before you begin Module 10.