1.GREENHOUSE EFFECT AND CLIMATE CHANGE by Brenda Batres

2. The Earth's climate is changing in ways that affect our weather conditions, oceans, snow, ice, ecosystems and society. 3. GROUND TEMPERATURE The Earth's temperature depends on the balance between the energy entering and leaving the planet's atmospheric system. Many factors, both natural and human causes changes in Earth's energy balance, including: 4. The changes in the greenhouse effect, which affects the amount of hea retained by the Earth's atmosphere 5. Variationsin the sun's energy that reaches Earth 6. The changes in the reflectivity of the atmosphere and land surface 7. The Earth's climate is changing... 8. These maps show temperatures across the world in the 1880s (left) and the 1980s (right), as compared to average temperatures from 1951 to 1980. This difference from average is called an anomaly. The map on the left shows that it was colder in the 1880's in most places. The map on the right shows it was warmer in the 1980s in most places. Earth's average surface temperature has increased almost 1.5F during the 20th century. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.3F-0.4F per decade. Source: NASA 9. The global average temperature increased by more than 1.3F over the last century.The average temperature in the Arctic rose by almost twice as much. The buildup of greenhouse gases in our atmosphere and the warming of the planet are responsible for other changes, such as: Changing precipitation patterns Increases in ocean temperatures, sea level, and acidity Melting of glaciers and sea ice 10. Natural causes alone can not explain many of these changes. Human activities contribute to climate change, primarily when downloading into the atmosphere each year billions of tons of carbon dioxide (CO2) and other heat-trapping gases, known as greenhouse gases. 11. GREENHOUSE When sunlight reaches Earths surface, it can either be reflected back into space or absorbed by Earth. Once absorbed, the planet releases some of the energy back into the atmosphere as heat (also called infrared radiation). Greenhouse gases (GHGs) like water vapor (H2O), carbon dioxide (CO2), and methane (CH4) absorb energy, slowing or preventing the loss of heat to space. In this way, GHGs act like a blanket, making Earth warmer than it would otherwise be. This process is commonly known as the greenhouse effect. 12. GREENHOUSE GASES 13. SOURCES OF EMISSIONS OF GREENHOUSE GASES The main sources of emissions of GHG in Mexico are: 14. Electricity production Electricity production generates the largest share of greenhouse gas emissions. Over 70% of our electricity comes from burning fossil fuels, mostly coal and natural gas. 15. Transportation - Greenhouse gas emissions from transportation primarily come from burning fossil fuel for our cars, trucks, ships, trains, and planes. Over 90% of the fuel used for transportation is petroleum based, which includes gasoline and diesel 16. Industry - Greenhouse gas emissions from industry primarily come from burning fossil fuels for energy as well as greenhouse gas emissions from certain chemical reactions necessary to produce goods from raw materials. 17. Commercial and Residential - Greenhouse gas emissions from businesses and homes arise primarily from fossil fuels burned for heat, the use of certain products that contain greenhouse gases, and the handling of waste. 18. Agriculture - Greenhouse gas emissions from agriculture come from livestock such as cows, agricultural soils, and rice production. 19. Land Use and Forestry - Land areas can act as a sink (absorbing CO2 from the atmosphere) or a source of greenhouse gas emissions. In the United States, since 1990, managed forests and other lands have absorbed more CO2 from the atmosphere than they emit. 20. IMPACTS Climate change may increase or decrease precipitation, influence yields of agricultural crops, affect human health, cause changes in forests and other ecosystems, or even affect our energy supply. 21. WHAT YOU CAN DO ... The reduce, reuse, and recycling in your home helps conserve energy and reduce pollution and emissions of greenhouse gases from extraction, manufacturing and disposal. If there is a recycling program in your community, recycle your newspapers, soda bottles, paper and other products. Also the composting of food waste and yard cleanup reduces the amount of waste you send to landfill and reduces emissions of greenhouse gases. 22. REFERENCES http://www.epa.gov/ http://www.inecc.gob.mx/