In our work, students initially understand that greenhouse
gases are involved in the global warming and that
heat from the sun warms the Earth. Their post-test
responses show that they learn that greenhouse gases
‘‘trap’’ energy to warm the Earth’s surface. Most fail to
understand that the greenhouse gases trap infrared energy
rather than solar energy. Although we do not see evidence
of a complete, integrated understanding of the greenhouse
effect and global warming for all students, we do see
evidence that they are revising their knowledge. This is
consistent with Vosniadou and Brewer’s conceptual change
theory that describes conceptual change as a gradual,
continuous process. As they reconcile new ideas with their
pre-existing knowledge, students have generated an intermediate
representation of the greenhouse effect that
includes correct and incorrect ideas.