Water Conservation versus Ecosystem Preservation part of Dilemmas
Nearly all of the water in the Colorado River system is removed for agricultural, industrial, and residential uses before it reaches the mouth of the river. However, the water delivery system in southern Arizona and California has a number of leaks (mostly seepage through the bottom of unlined canals), by which some of the water moves through the subsurface and back into the lower reaches of the river, sustaining a limited ecosystem in the Colorado River Delta.

Too Cool for Science part of Dilemmas
On a frigid Minnesota afternoon, I had just finished a mini-lecture in my introductory class, and I threw out a question to the whole class. Chris responded enthusiastically with a wonderful and correct contribution. At which point, Sam groaned and said, in a voice audible to the entire class,"suck up!" A few other eyes rolled, and other hands that had been raised were slowly lowered.

Transforming Attitudes and Killing Interest in Introductory Geology Classes for Majors part of Dilemmas
Students enter Physical Geology with great interest in geology regardless of declared major or academic rank. Approximately 70% of students (n=306) declared a high level of interest in multiple aspects of geosciences. However, at the end of the semester, less than 30% of the same population recorded a high interest in geology (regardless of declared major, academic rank).

Recruiting Under-represented Minorities into a Geoscience Program part of Dilemmas
Students of under-represented groups have little to no interest in the Svalbard REU program. Despite concerted recruitment efforts, members of under-represented groups often don't apply to the program. We use direct mailings (with recruitment posters) and presentations, advertisement at national meetings with minimal success. We can not seem to be able to place this paid opportunity on their "radar-screen."

Mineralogy Motivation - A Real-Life Tale of Woe part of Dilemmas
I teach mineralogy (do you feel my pain?). Mineralogy has a reputation for being a "weed out" course, and not very many students look forward to taking this class. But in addition, in our department I've encountered another problem: we have a degree option in paleontology, and students who self-select this option basically want to be Jack Horner and head out to the hills to dig up dinosaur bones.

Fixation on grades part of Dilemmas
Each semester our university offers several large-enrollment (n ~ 220) sections of a lecture-based introductory physical geology course. Although the course can be counted toward a geological sciences major, it functions mostly as a service course that provides non-major students a science credit necessary for graduation.

Meeting learning goals with a below average course part of Dilemmas
During the fall 2006 semester I taught a first year writing seminar entitled "The World's Oceans in the Global Environment," a course designed to introduce students to important topics in marine science in the context of Earth systems science, as well as key issues in ocean policy (e.g., fisheries, implementation of marine protected areas, etc.). As a writing seminar, most student work during the semester was in the form of writing assignments.

Scientific uncertainty and global warming part of Dilemmas
Climate change is the major environmental issue facing all inhabitants of spaceship Earth. As Earth science educators, we must inform students about the scientific consensus on global warming and projections of future warming through this century. Recent research has resulted in a dramatic advance in our understanding of climate history.

Empathy part of Dilemmas
Students in a small upper level class discussing global warming students argue that anything we do to "save" the environment is worth any cost and ultimately benefits everyone equally. We explain that a person in another country might be willing to accept a degraded environment in exchange for economic improvement. Students are willing to accept that as an intellectual argument but it becomes clear in subsequent discussions that they did not change their arguments to accommodate this idea.

Trilobites Live! part of Dilemmas
I teach Historical Geology at a large public university. As I was setting up class the other day, a student, Eric, nervously approached me and asked a question that caught me off-guard. "How do you know for sure that trilobites and humans didn't co-exist?" he asked. I smiled, thinking he was making a joke. After all, we were several weeks into a second-semester geology course and this was the first time he had expressed these ideas. "Nice one," I said, "how can I really help you today?" But then I realized he wasn't trying to be funny. His face turned stoic and serious, but before I could gather myself and formulate an answer, he continued, "You throw around these huge numbers for the age of the earth, the age of the rocks and the age of the fossils. But how do you know? Aren't you just repeating the numbers that you have read elsewhere? In a church group, we learned that humans and all other life were created at the same time, only a few thousand years ago."