Carbon in the Atmosphere Module 4 ©2013 Educurious Partners. All rights reserved. www.educurious.org

©2013 Educurious Partners. All rights reserved. www.educurious.org The Keeling Curve Charles Keeling began collecting continuous atmospheric CO2 data in 1958 at the Mauna Loa Observatory in Hawaii. Over time, he found that: CO2 is steadily increasing CO2 fluctuates about 5 parts per million (5 ppm) each year due to due seasonal plant cycles: Plants take up CO2 in the spring when they bloom, and release CO2 in fall when leaves fall and decay. CO2 levels are highest in April and lowest in October. Visit: http://www.esrl.noaa.gov/gmd/ccgg/trends/ for current Mauna Loa data. ©2013 Educurious Partners. All rights reserved. www.educurious.org

©2013 Educurious Partners. All rights reserved. www.educurious.org CO2 and Climate Industrial Revolution Top Graph: Historic levels of CO2 rarely exceeded 300 ppm, but since the Industrial Revolution, levels have steadily risen to 392 ppm in 2011. Bottom Graph: CO2 fluctuations match temperature fluctuations. Temp Images from wikimedia: http://commons.wikimedia.org/wiki/File:Carbon_Dioxide_400kyr.png http://commons.wikimedia.org/wiki/File:Vostok_Petit_data.svg CO2 Concentration ©2013 Educurious Partners. All rights reserved. www.educurious.org

Why is CO2 Building in the Atmosphere? The amount of carbon dioxide on Earth is a balance between carbon dioxide production through respiration (animals breathing out CO2), decay or combustion, and carbon dioxide uptake through photosynthesis. Fossil fuels are made of decayed plants and animals that are hundreds of millions years old. Burning fossils fuels releases carbon that was stored underground for those millions of years, and creates an imbalance in the carbon cycle. Deforestation also decreases Earth’s ability to take up excess carbon. ©2013 Educurious Partners. All rights reserved. www.educurious.org

©2013 Educurious Partners. All rights reserved. www.educurious.org The Carbon Cycle Soil, terrestrial plants, algae, and phytoplankton are carbon sinks – they take carbon out of the atmosphere through storage and photosynthesis. Plant and animal respiration, decomposition, fires, and fossil fuel emissions are carbon sources – they add carbon to the atmosphere. Which carbon source is causing an imbalance in the carbon cycle? Historically, over hundreds of thousands of years, carbon sinks and sources have fluctuated, causing altered atmospheric CO2 levels as well as global temperatures. Burning fossil fuels is a modern carbon sink addition to the carbon cycle, and is why CO2 levels are rising quickly and to record highs. Image from Wikimedia Commons: http://en.wikipedia.org/wiki/Carbon_cycle ©2013 Educurious Partners. All rights reserved. www.educurious.org

Evidence and Impacts Jigsaw In groups of 2-4, you will answer 1-2 questions about the following topics. You will then teach your classmates about your topic. When the other students share their answers, take notes so at the end of this activity you have answered all of the questions. Topics include: Types of Carbon in the Atmosphere Melting Glaciers Shrinking Sea Ice Ancient Climate Data Thawing Permafrost Higher Temperatures Increased Ocean Acidity More Droughts Warmer Oceans Wilder Weather Rising Sea Level Changing Rain and Snow Patterns Less Snowpack ©2013 Educurious Partners. All rights reserved. www.educurious.org