One stereotypical public perception of scientists is of stoic, noble figures who don lab coats and work religiously for years on end until they are rewarded with a major discovery. This image is, of course, flawed for many reasons — one being that scientists, like everyone else, are emotional about their work. The lucky ones are passionate about it. And emotion is an important force motivating experiments and career decisions.

This week we delve into the fossil-fuels industry and explore opportunities available to geologists, chemists, physicists and computer scientists (see page 832). For many, such careers can be rewarding, financially and otherwise. Much of this work has a satisfying problem-solving element. The aim is clear, as are the rewards: find the oil (or a better way to extract it) and your company will profit — potentially in a big way. And with the demand for new recruits still high despite the economic downturn, salaries should stay sizeable.

Some scientists, though, might have reservations about such work. Oil and coal companies can be seriously detrimental to the environment and to wildlife. Those who feel science is a means to work towards a greater good — curing disease or solving the energy crisis — might frown on such vocations.

Krystal Walker, a student at the University of Utah's mining programme in Salt Lake City and a self-identified environmentalist, decided she was going to try to change these companies' practices from the inside, by finding ways to minimize their impact on the landscape. This, of course, is a bold gambit with no guarantees.

Those with a passion for saving our planet or benefiting society may be better served by a job in a non-governmental organization (see Nature 455, 1002–1003; 2008). As Anumita Roychowdhury, associate director of the Centre for Science and Environment (CSE) in Delhi, India, put it in our recent story: the CSE looks for people who are a “little mad about things”. For those people, the practical problem-solving of the oil and coal industries might not be quite enough.