Hobbies And Interests
Adaptations
You could focus your science project on adaptations that plants and animals have developed to survive in a harsh desert climate. For example, you could look at the gila monster, which stores extra water in its tail, or at the antelope squirrel, who has adapted to withstand internal body temperatures that exceed 104 degrees Fahrenheit, an internal temperature that causes serious damage to human brains. You can look at animals and plants that live in the desert and compare them with close relatives who live in more mild climates.
Average Rainfall
For a science project, you could analyze average annual rainfall from deserts around the world and perform a comparative study. For example, you can look at the different types of deserts, including hot and dry deserts, semi-arid deserts, coastal deserts, and cold deserts, and compare the rainfall of each. Find data to suggest that average annual rainfall in the 21st century is either more or less than it was in the past, as far back as is recordable.
Changes to Desert Regions
Your science project can focus on changes to desert regions as a result of human actions, locally, regionally and globally. You can look at average annual rainfalls and establish a cause-and-effect relationship between consumption of fossil fuels and other greenhouse gases and changes to a desert environment over a period of time, such as 25 years. You should focus especially on deserts for which data exists going back decades or centuries, if possible.
Fossils
You can focus your science fair project on the history of desert regions, using fossils to create a picture of what type of life the now-desert would have supported millions of years ago. For example, look at the Peru desert, where in 2007 paleontologists from North Carolina State University found fossils of giant penguins -- they were about the size of humans -- who lived in South America approximately 35 million years ago.