A. Greenhouse Warming Experiment Fill in the tables below with the temperature reading at each time interval. We will stop making measurements when the thermometer has reached a constant value. Table 1. Temperature under the Greenhouse Time (minutes) Temperature ( F) 0 68 10 69.5 20 72 30 73 40 73.5 50 74 60 74 Plot your results from the experiment on the graph below. Temperature (F) 80 78 76 74 72 70 68 66 0 10 20 30 40 50 60 Minutes with Lamp On
B. The Phases of Water Imagine a glass with a cool drink in it on a hot day. The outside of the glass becomes wet where did that water come from? some students will guess it leaks through the glass from the inside Try an experiment with a cold colored drink or a glass of Coke. Wipe the water from the outside of the glass. Is it the same color as the drink or is it clear? Do you think it s from inside the glass or outside? The water should be clear, which suggests that it s not from inside the glass What could cause water vapor in the atmosphere to form a liquid layer on the outer surface of the glass? The cold temperature of the drink causes water vapor in the air to form liquid water when it collides with the cold glass What is this process called? condensation When liquid water condenses in the atmosphere, what happens? clouds form and this may lead to precipitation, for example rainfall
C. Climate Change and the Water Cycle Four stations will be set up Each station has a pair of plastic containers to hold the liquid or solid water Station Phase Temperature Observations (evaporation, melting?) 1 Water Hot Water in the container got warm and began to evaporate, evidence was condensation on INSIDE of container 2 Ice Hot 3 Water Cold Ice in container melted and turned into water, there may be some condensation on the outside of the container Water in container got cold but did not freeze, no evaporation 4 Ice Cold Ice in container barely melted at all, no evaporation How can you tell if water had evaporated in the container? Condensation will form on the side of the container wall where water vapor exists Compare stations 1 & 2 which station had more water evaporate? Station 1 Compare stations 1 & 3 which station had more water evaporate? Station 1
Fill in your own answers If the Earth gets warmer, how will the water cycle change? Will there be more water in the oceans or less? Will there be more snow or more rain? Will there be more clouds or less? More water vapor can exist in a warmer atmosphere, which will deplete stocks of liquid water on the Earth s surface. Ice caps and glaciers melt, releasing freshwater into the oceans. Feedback loops exist because water vapor itself is a greenhouse gas and because ice is a reflective surface, so if it melts, less sunlight is reflected back into space and more is absorbed by the planet making temperatures increase further. The melting of ice caps will release more water into the ocean, but higher temperatures also increase evaporation, taking water out of the ocean. The balance between the two effects is uncertain. Rain will be more frequent than snow if temperatures are warmer. Areas that depend on winter precipitation for water supplies may have problems because snow is better conserved over the year. Liquid water supplies in a reservoir tend to evaporate, while a snowpack is more resistant to loss because additional energy has to be put in to get snow to melt. There will be more water vapor in the atmosphere if it is warmer, and it is less likely to condense to form clouds. Clouds are one of the most uncertain parts of climate change, because of the additional effects of aerosols. The existence of clouds helps to cool the Earth by blocking sunlight from reaching the surface.
What are some ways to help prevent more global warming? Use cars less, ride a bike, walk, take the bus Turn off lights and appliances when not using them Wear lots of clothes when it s cold and less when it s hot, instead of using heating or air conditioning Don t buy things with too much packaging Use fluorescent light bulbs Don t use gas-powered lawnmowers Etc.. What are some ways that you can help conserve water? Take shorter showers Water the lawn early in the morning Don t leave the tap running while brushing teeth Don t use a hose to clean driveways and sidewalks Only run full loads in dishwasher or washing machine Don t pour oil down the drain Etc..