Children looking for an introductory global warming topic can carry out their own original field research assessing public views toward global warming. Have children write questionnaires and submit them to an adult before asking them to their friends, classmates, family and teachers. Youngsters should record the age and gender of their survey respondents before asking whether respondents think global warming is a "serious problem" for society and whether they would agree with the government spending millions of dollars every year on tackling climate change. Young scientists should then make graphs of their results, such as a simple yes-and-no bar chart showing what percentage of respondents regards global warming as a serious problem for society.
Air pollution is an increasingly prevalent factor in global warming. The release of harmful greenhouse gases from vehicles, landfill sites and industrial premises all contribute to local air pollution, which children can measure through this experiment. Have children coat the surface of 10 microscope slides with a light film of petroleum jelly before placing them in different environments, such as their garden, family car, classroom and bathroom, with the jelly side facing up. Have young scientists label each slide so they known where it was located. After two days, have children collect the slides and view them through a microscope before predicting what percentage of the slide is covered in particles based upon what they see. Youngsters should also take several photographs of their experiment, which they can present on their science fair stall along with an explanation of their results.
One simple but useful global warming project for children allows them to witness the greenhouse effect before their eyes. Have youngsters lay two identical tea towels on a table and place identical thermometers at the center of each towel. Instruct children to then place a thick glass dish, such as those used to cook casseroles, over the top of one of the thermometers. Have young scientists place two desk lamps with the same wattage bulb directly above the thermometers, shining their light down upon them. Students should then start a timer and take a temperature reading from both thermometers every 30 seconds for at least 10 minutes before concluding their experiment. Children can produce a line graph with a different colored line for each thermometer, with time in 30-second increments on the horizontal axis and temperature in Fahrenheit on the vertical axis, and present this at the science fair.
This global warming science fair project, which is targeted at slightly older or academically gifted children, looks at the effect of global warming on the circulation of salty ocean water, known as thermohaline circulation. Have students mix 4 tsp. of salt into an 8-oz. glass of tap water from the fridge and add it into a wide-mouthed, 1-quart-volume glass jar. Instruct youngsters to take a second 8-oz. glass of room temperature water and stir in 4 tsp. of salt and 1/2 a medicine dropper of red food coloring. Children should then hold a desert spoon over the mouth of the refrigerated water and slowly pour the red room temperature water into the spoon so it spills over and mixes with the cold water. Youngsters should observe the outcome carefully, as the colder water is layered below the warmer water. Students should repeat this experiment with different temperatures and salinities of water to see how they can explain how global warming can affect thermohaline circulation.