* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Do NOT write on
Low-carbon economy wikipedia , lookup
Heaven and Earth (book) wikipedia , lookup
Climate change adaptation wikipedia , lookup
Climate change denial wikipedia , lookup
Economics of global warming wikipedia , lookup
Snowball Earth wikipedia , lookup
Climate governance wikipedia , lookup
Climatic Research Unit documents wikipedia , lookup
Citizens' Climate Lobby wikipedia , lookup
Climate engineering wikipedia , lookup
Global warming controversy wikipedia , lookup
Climate sensitivity wikipedia , lookup
Climate change and agriculture wikipedia , lookup
Media coverage of global warming wikipedia , lookup
Fred Singer wikipedia , lookup
General circulation model wikipedia , lookup
Effects of global warming on human health wikipedia , lookup
Climate change in the Arctic wikipedia , lookup
Mitigation of global warming in Australia wikipedia , lookup
Effects of global warming on humans wikipedia , lookup
Climate change in Tuvalu wikipedia , lookup
Effects of global warming wikipedia , lookup
Climate change and poverty wikipedia , lookup
Effects of global warming on oceans wikipedia , lookup
Scientific opinion on climate change wikipedia , lookup
Global warming hiatus wikipedia , lookup
Politics of global warming wikipedia , lookup
Surveys of scientists' views on climate change wikipedia , lookup
Global Energy and Water Cycle Experiment wikipedia , lookup
Climate change, industry and society wikipedia , lookup
Climate change in the United States wikipedia , lookup
Public opinion on global warming wikipedia , lookup
Future sea level wikipedia , lookup
Attribution of recent climate change wikipedia , lookup
Global warming wikipedia , lookup
Instrumental temperature record wikipedia , lookup
Solar radiation management wikipedia , lookup
CLASS SET Climate Change Do NOT write on What is causing it? How do we know it is happening? A blanket around the Earth Figure 1: A layer of greenhouse gases – primarily water vapor, and including much smaller amounts of carbon dioxide, methane and nitrous oxide – acts as a thermal blanket for the Earth, absorbing heat and warming the surface to a lifesupporting average of 59 degrees Fahrenheit (15 degrees Celsius). Most climate scientists agree the main cause of the current global warming trend is human expansion of the "greenhouse effect"1 — warming that results when the atmosphere traps heat radiating from Earth toward space. Certain gases in the atmosphere block heat from escaping. Long-lived gases that remain semipermanently in the atmosphere and do not respond physically or chemically to changes in temperature are described as "forcing" climate change. Gases, such as water vapor, which respond physically or chemically to changes in temperature are seen as "feedbacks." We live in a greenhouse Life on Earth depends on energy coming from the sun. About half the light reaching Earth's atmosphere passes through the air and clouds to the surface, where it is absorbed and then radiated upward in the form of infrared heat. About 90 percent of this heat is then absorbed by the greenhouse gases and radiated back toward the surface, which is warmed to a life-supporting average of 59 degrees Fahrenheit (15 degrees Celsius). On Earth, human activities are changing the natural greenhouse. Over the last century the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (CO2). This happens because the coal or oil burning process combines carbon with oxygen in the air to make CO2. To a lesser extent, the clearing of land for agriculture, industry, and other human activities have increased concentrations of greenhouse gases. The consequences of changing the natural atmospheric greenhouse are difficult to predict, but certain effects seem likely: On average, Earth will become warmer. Some regions may welcome warmer temperatures, but others may not. Warmer conditions will probably lead to more evaporation and precipitation overall, but individual regions will vary, some becoming wetter and others dryer. A stronger greenhouse effect will warm the oceans and partially melt glaciers and other ice, increasing sea level. Ocean water also will expand if it warms, contributing to sea level rise. Meanwhile, some crops and other plants may respond favorably to increased atmospheric CO2, growing more vigorously and using water more efficiently. At the same time, higher temperatures and shifting climate patterns may change the areas where crops grow best and affect the makeup of natural plant communities. CLASS SET Do NOT write on Climate change: How do we know? Figure 2: This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO 2 has increased since the Industrial Revolution. The Earth's climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives. “Scientific evidence for warming of the climate system is unequivocal.” CLASS SET Do NOT write on - Intergovernmental Panel on Climate Change The current warming trend is of particular significance because most of it is very likely human-induced and proceeding at a rate that is unprecedented in the past 1,300 years.1 Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. This body of data, collected over many years, reveals the signals of a changing climate. The heat-trapping nature of carbon dioxide and other gases was demonstrated in the mid-19th century.2 Their ability to affect the transfer of infrared energy through the atmosphere is the scientific basis of many instruments flown by NASA. There is no question that increased levels of greenhouse gases must cause the Earth to warm in response. Ice cores drawn from Greenland, Antarctica, and tropical mountain glaciers show that the Earth’s climate responds to changes in greenhouse gas levels. They also show that in the past, large changes in climate have happened very quickly, geologically-speaking: in tens of years, not in millions or even thousands.3 The evidence for rapid climate change is compelling: Sea level rise Global sea level rose about 17 centimeters (6.7 inches) in the last century. The rate in the last decade, however, is nearly double that of the last century.4 Figure 3: Republic of Maldives: Vulnerable to sea level rise. Credit: Chumash Maxim/Shutterstock.com Global temperature rise All three major global surface temperature reconstructions show that Earth has warmed since 1880.5 Most of this warming has occurred since the 1970s, with the 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years.6 Even though the 2000s witnessed a solar output decline resulting in an unusually deep solar minimum in 2007-2009, surface temperatures continue to increase.7 CLASS SET Do NOT write on Warming oceans The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of 0.302 degrees Fahrenheit since 1969.8 Shrinking ice sheets The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA's Gravity Recovery and Climate Experiment show Greenland lost 150 to 250 cubic kilometers (36 to 60 cubic miles) of ice per year between 2002 and 2006, while Antarctica lost about 152 cubic kilometers (36 cubic miles) of ice between 2002 and 2005. Figure 4: Flowing meltwater from the Greenland ice sheet Declining Arctic sea ice Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.9 CLASS SET Do NOT write on Visualization of the 2007 Arctic sea ice minimum Glacial retreat Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.10 The disappearing snowcap of Mount Kilimanjaro, from space. Extreme events The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events.11 Ocean acidification Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent.12,13This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.14,15 Decreased snow cover Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier.16 CLASS SET Do NOT write on Name: ______________________________________________________ Date: _____________________ Period: _____ Climate Change Directions: Read about Climate Change in the articles provided and answer the questions below. 1. What is the greenhouse effect? 2. How do greenhouse gases act like a “thermal blanket?” 3. How have humans contributed to the increase in greenhouse gases and climate change? 4. Climate change and global temperature fluctuations have occurred naturally over time. How do we know that humans are having an effect on climate change? Use the graph in Figure 2 to support your answer. 5. What evidence have scientists used to prove that global warming trends are man-made? Name at least 3 examples or types of evidence. 6. Imagine you live in the city pictured in Figure 3. The sea level has already risen 6 inches, now imagine the sea level continues to rise 12 more inches. How would this affect your life? What changes would occur? How would you solve these problems? 7. How is the warming of the ocean going to affect wildlife? Be specific. 8. How is the melting of the ice caps and ice sheets going to affect wildlife? Be specific. 9. What is ocean acidification? 10. What can we do now to slow the rate of global warming and climate change? Hint: Think about our current energy resources and options for the future.