Global Climate Change (45 minute lesson) Title: Global Climate Change: What is it? Why should we care? What can we do? Description: This lesson provides a brief overview of climate change, problems associated with climate change, and strategies for reducing anthropogenic effects on climate change. Objectives: Following this lesson, students should be able to: 1. Describe the difference between weather and climate. 2. Explain how greenhouse gases produced by humans affect global climate. 3. Discuss potential impacts of global warming on plants, animals, and people. 4. Design and evaluate strategies for mitigating human effects on global climate. Intro: Global Climate Change: What is it? Why should we care? What can we do? Over the next few minutes we’re going to talk about a big problem facing our planet. Some of you may have heard about this before. It’s called climate change. To understand what climate change is and why it might be bad, we’ll have to answer a few questions. Let’s start with the first one… Part I: What is climate? (5 minutes) Climate and weather are similar, but they’re not exactly the same things. Weather is short term and local (EX: It’s raining today OR it’s been cold this week). Climate is long term and often global (EX: The northern hemisphere is cold in winter, Alaska is cold and wet, the Sahara Desert in Africa is hot and dry). When scientists talk about climate change, they mean changes in weather over a very long time, not just a few days or weeks! Part II: Does Earth’s climate normally change? (5 minutes) Yes. Cyclical changes in Earth’s climate have occurred for millions of years. A cycle is something that happens over and over again. Sometimes the Earth goes through a long period of time when it is very warm (EX: Dinosaurs in Jurassic Period). Sometimes it can be very cold for thousands of years (EX: Ice Age). These changes are often caused by atmospheric and oceanic cycles, among other factors (EX: El Niño warming event every 4-7 years). So, the Earth can be warmer or cooler depending on cycles. Well… if climate change is normal, then why should we be worried? Because, based on data from weather stations around the world, most scientists think that - in the past 100 years - the Earth has been warming up FASTER than it ever has before! Since 1890, the 5 warmest years on record are all in the last decade (NASA, 2007).

Part III: What’s causing this new, super-fast warming? (10 minutes) To understand why the Earth is suddenly warming up so quickly, you have to understand the greenhouse effect. (Draw diagram and discuss as you proceed.)  Earth’s temperature depends on heat from the sun.  Light rays hit earth. Some deflect into space.  However, many rays of sunlight are trapped by atmospheric gases like carbon dioxide and methane. These are known as greenhouse gases (and they function similar to a plant greenhouse). In fact, these GHGs trap 90% of the sun’s energy in send it back to Earth. Without them, our planet would be cold and uninhabitable.  Today, however, humans have added more GHGs to the atmosphere than there has ever been before. Most of these GHG’s come from burning fossil fuels like coal, oil, and gas (many others come from land use change). (Draw a few examples GHG pollution sources such as cars, factories, etc.) More GHGs in the air means that more sunlight bounces back to Earth and the planet gets warmer. (Show graph depicting changes in Earth’s average temperature and atmospheric CO2 over time.) This graph will help you see the relationship between GHGs in the air (in this case CO2) and average global temperature. We know the atmospheric CO2 levels from thousands of years ago thanks to ice cores from Antarctica (air is trapped in the ice and we can drill in, recover the air bubbles, and measure the CO2 content). Over the last few decades, atmospheric CO2 has been measured at observatories like the one on Mauna Loa, Hawaii. Looking at the graph you can see that CO2 and temperature are related. When one goes up, the other one goes. We would expect this because of the greenhouse effect. Look how much higher atmospheric CO2 is today than it has ever been before. What do you think that will do the Earth’s temperature? No wonder our planet is getting hot fast! Part IV: How does climate change affect plants, animals, and people? (10 minutes) Climate change can cause many different problems for plants, animals, and people. Can you think of any? Here are a few examples (pictures on slides):  Melting ice caps reduce habitat for polar species like the polar bear, penguins.  Retreating glaciers means smaller lakes and rivers and less water for plants and animals.  As ice melts, more water flows into the ocean and sea levels rise. Most people on Earth live close to oceans. Many cities could be flooded, and some may end up underwater. (Sea levels have already risen 10-20 cm in the past 50 years (IPCC, 2006). In the next 100 years, some experts forecast a rise as high as 1 m).  Variable precipitation and stronger storms will make weather harder to predict, creating major problems for people and animals.  Many species of fish and amphibians cannot shift their ranges quickly enough to adjust to the warmer rivers. They may go extinct.  Many species of birds and insects are migrating from winter habitats too early because of the warmer temperatures, and they are struggling to find food and survive.

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Plant composition in particular areas may change dramatically. Forests will move north and to higher elevations. Grasslands will likely become much more prevalent in the southern U.S. Ocean acidification – a direct result of rising CO2 levels – will severely disrupt marine ecosystems. Coral reefs can’t form if calcium carbonate is easily dissolved, and that will happen if the oceans absorb too much CO2. Warmer temperatures make it easier for disease to spread around the world.

Part V: What can we do to reduce human effects on climate change? (15 minutes) We are a big part of the problem! Together, the U.S. and China account for almost half of global carbon emissions each year (Center for Global Development, 2007). Fortunately, there are many things that you and other people can do reduce the amount of GHGs that humans are putting in the atmosphere every year. Remember that, by reducing GHGs like CO2, we can reduce the human induced effects on climate change. Can you think of anything that you can do to help? (Brainstorm some ideas with the class.) Here are few examples (hints on slides; many from Cherry & Braasch, 2008; EPA, 2009):  If a million families drive fewer than 15 miles each week, this stops 450,000 tons of CO2/year.  If a million drivers turn off their cars for just 10 minutes a day instead of idling, this stops 27,500 tons CO2/year. If each of the country’s schools required buses (440,000) to stop idling for 15 minutes per day, this stops 97,000 tons of CO2/year.  If 250,000 families use a 40 mpg car rather than their previous car, this stops 690,000 tons of CO2/year.  If a million kids recycle 50% of everything recyclable, this stops 1.2 million tons of CO2/year.  If a million kids stopped drinking bottled water and other drinks from plastic bottles, this stops 15,000 tons of CO2/year.  If a million kids turn off the TV and computer for 2 hours a day, this stops 80,000 tons of CO2/year. Turn the computer off overnight – that’s another 475,000 tons of CO2/year.  If a million kids eat one less cheeseburger a week, this stops 170,000 tons CO2/year.  If a million kids each plant one tree in their yards and it reaches maturity, those trees will absorb 160,000 tons of CO2/year.  If a million families switched to buying locally produced produce food for a year, or grow their own, it would stop 625,000 tons of CO2/year.  If a million kids replace 6 incandescent bulbs with compact fluorescents, this stops 300,000 tons of CO2/year.  If a million households use cold water when washing laundry, it would stop 250,000 tons of CO2/year.  If a million families replaced household appliances with energy-star models, it would stop more than 3 million tons of CO2/year. *Note: There are about 55 million school kids in the U.S.

Other things that would help:  Turn off air conditioners! About 1/6 of all the electricity generated in the U.S. is used to air condition buildings.  Improve public transportation systems. Encourage fewer people to drive.  Use electricity generated by renewable energy (wind, sun, water)! Anything but fossil fuels! If you can, try to convince your legislators to do the same.  Help scientists understand the effects of climate change on animals. To do this, kids can participate in things like the annual Great Backyard Bird Count (this year it’s from Feb. 12-15) sponsored by the Audubon Society. For more information, visit: http://www.birdsource.org/gbbc/kids Conclusion: Now it’s your turn! Now it’s your turn to help fight human-induced global warming. You understand climate change. You know what causes it. You know the problems it can cause. You know ways to help. What are you waiting for? It’s time to start making changes in the way we live! Working together, we can make the Earth a great place to live for many generations to come!