Hi Penny,
That is an excellent question, and a rather difficult one to answer.
The effect of the recession on careers in science and engineering varies a lot, depending upon the specific field of science or engineering and the type of place someone works. I know engineers who work in the biotechnology and aerospace industry who have either been laid off already or are concerned that they may lose their jobs in the near future because the corporations they work for are not getting as much business. Even though my department has adequate funding from federal research grants right now, other departments at the university where I work have had to lay people off or ask them to take early retirement to save money.
People who are already working as scientists or engineers can protect themselves from financial difficulties during the current economic situation by making sure they keep their skills up to date, are open to using their skills in new and different ways, and are willing to work in a different field from their degree. One of the engineers I know who was laid off is going back to school to get a Master's degree, which will hopefully help her find an even better job in the future.
Hopefully, the recession will be over by the time you finish school. However, if you are interested in pursuing a career in science or engineering, there are things you can do to protect yourself from future economic downturns. When you choose a major in college, you should investigate the types of jobs available in a particular field (industry, academic, government), in what geographical area people in that field work, and if that field is expected to grow in the future. There is a tendency for scientists to become very specialized in one field, but it is a lot easier to find jobs if you have a broad range of skills that can be applied to many different areas.
Kris