To understand why Earth is getting warmer, it's important to consider why it's warm in the first place. The Sun, of course, is the source of energy that heats Earth, but something called the greenhouse effect is what keeps the planet relatively warm and stable.

Unfortunately, as this video explains, human activities have increased the amount of greenhouse gases in the atmosphere. This has caused the greenhouse effect to become stronger and Earth's average temperature to rise.

To learn more, watch the video on the left. When you've finished watching the video, print and fill out the Global Warming Connections Worksheet (PDF) to record what you know or have heard about global warming. Use a pencil so you can update it later.

It may seem like there's not much that you as an individual can do to slow global warming. However, as this video shows, our choices do have an effect on the amount of energy we consume, which in turn influences our contribution to greenhouse gases.

Watch the video, then answer the following questions in the box below.

• How do the points made in the video compare to the ideas you recorded on the Global Warming Connections worksheet?
• Did you learn anything new?
• Did the information in the video change any of your ideas? If so, make adjustments to your worksheet.

In the United States, the effects of global warming aren't obvious yet. Turn on the faucet or go to the grocery store, and there's no sign that our most basic resources are at risk.

However, in other parts of the world, the threats are clear. Himalayan glaciers supply water for nearly one-half of the world's people. And now, because of global warming, the glaciers are shrinking.

To learn more, watch this video. When you finish, record your answers to these questions in the box below. Then, look again at your Global Warming Connections worksheet and make any additions or changes based on this information.

• Why is global warming causing glaciers to shrink?
• What effects might this have on the people who live downstream and rely on the glaciers for water?
• Can you identify other locations, including in the U.S., where the population relies on glacial waters?

Reducing our consumption of energy is one step we can take to slow global warming, but many experts think we also need to change how we produce energy. These videos highlight two technological solutions:

• Continue using coal to generate power, but then capture the carbon dioxide gas produced before it is released into the atmosphere.
• Use the clean, renewable energy of the Sun to power our homes.

Watch these two videos, and record your answers to the following questions in the box below. Then, continue to update your Global Warming Connections worksheet as needed.

• Are you convinced that either clean coal or solar technologies are the answer to global warming, or do you think we need additional solutions? Explain.
• Which approach do you think can have a bigger impact—a major technological shift in how we produce energy, or everyone pitching in to reduce consumption?

One of the greatest things about making your own video is that there is no right or wrong way to do it. The style of your video and the ideas you choose to explore are up to you.

These videos, all submitted by young producers, tackle the subject of global warming. Each has its own approach, style, and focus. Take some time to watch the videos and then choose your favorite video to focus on.

Write below what you liked most about the video you chose. What is the main point of the video? How does the video support and emphasize this main point?

Now it's your turn: What do you want to say about global warming? Check with your teacher to find out if you will be working individually, in pairs, or in small groups to produce your video. If you're not working alone, you will need to collaborate with your partner or team to decide on a main point for your video.

To help you develop your idea, write down your responses to these questions.

• What do you want people to know about global warming? (For example, do you want to explain its causes, talk about its impacts, or promote some possible solutions?)
• Who is your audience? (For example, is it your friends or family, your community, the government, or people across the country or around the world?)

If you are working with a partner or in a group, discuss your responses to the questions. Remember, there are no right or wrong answers. You just want to find an idea that interests you and that you think would be interesting to others.

If you need more information, or want to see other examples, check out these Teachers' Domain videos.

• Global Warming: Carbon Dioxide and the Greenhouse Effect
• Global Warming: The Developing World
• Arctic Climate Perspectives
• Polar Bears and Climate Change
• Taking the Earth's Temperature
• Hurricane Katrina: A Scientist's Response
• Pennsylvania Energy: Energy from the Sun
• Making Electricity at a Coal-Burning Plant
• Climate Change
• Energy Sources
• Capturing Carbon

Now that you have thought about what you want to say—your main point—it's time to think about how you want to say it. You'll begin by developing a treatment. This is a document in which you describe what you want your video to show and say, and how you want it to look and sound. Treatments can be text descriptions or they can show the video's concept in a comic book-like graphic style (known as a storyboard).

Here are the treatments that were created for three of the student videos you watched earlier: Open Call Youth Voices Treatments (PDF)

To see how a typical storyboard looks, check out the Sample Storyboard: Ecopiphany (PDF).

As before, if you're working with a partner or in a small group, you will need to collaborate to refine the focus and basic approach of your video and then to write the treatment or create the storyboard.

Use the Video Treatment Worksheet (PDF) provided here to write a text treatment or draw a storyboard for your global warming video.

Be sure to record:

• your main point
• your thoughts about the visual style of your video
• ideas about whom you could or what kinds of visuals you could feature in your video
• the order in which you could present your ideas and information

In your script, you will write out exactly what you want to say and how you want to say it—through narration, dialogue, or interviews, and with visuals. You won't be able to identify all of the visuals you might use, nor will you be able to script the answers of the people you plan to interview. You will have to use your imagination to describe the visuals and audio you hope to capture once you begin videotaping and editing. It is important to think of your script as a working document that will constantly evolve as you move forward with your project.

Before you begin drafting your script, review the Sample Script: Ecopiphany (PDF) to see how it is organized. Note how in each scene, the scriptwriter identifies what viewers would see and hear at any given moment.

Scripts can also contain notes about locations, action, lighting, camera angles and movements, edits, and visual and sound effects. Although the length of scripts will vary, a two-page script generally translates to a video that is about three minutes long—a good length to aim for in this activity.

With this sample script and your treatment as a guide, use the Video Script Worksheet (PDF) or a computer to write a draft script for your video.

You have completed a critical stage of the process: preproduction. Now you're ready to begin production, which includes:

• recording video
• gathering stock footage and images
• capturing digital assets
• editing

Your teacher will help you or your team use the equipment; find images, music, sound effects, and footage for your video; and put all of the pieces together.

When you're done, you can share your video with your classmates and see their projects, as well. If you want to share your project outside of your own classroom, your teacher can help you distribute your video on Teachers' Domain or on other online sites.