CHEMISTRY READING ASSIGNMENT

CHEMISTRY READING ASSIGNMENT - Frequently Asked Questions...

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Back to Basics Frequently Asked Questions ABOUT GLOBAL WARMING AND CLIMATE CHANGE:
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2 The Earth’s climate is changing. In most places, average temperatures are rising. Scientists have observed a warming trend beginning around the late 1800s. The most rapid warming has occurred in recent decades. Most of this recent warming is very likely the result of human activities. Many human activities release “greenhouse gases” into the atmosphere. The levels of these gases are increasing at a faster rate than at any time in hundreds of thousands of years. We know that greenhouse gases trap heat. If human activities continue to release greenhouse gases at or above the current rate, we will continue to increase average temperatures around the globe. Increases in global temperatures will most likely change our planet’s climate in ways that will have significant long-term effects on people and the environment. This fact sheet addresses the most frequently asked questions about the science of global warming and climate change. The Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment Report (2007) serves as the key reference for this brochure. The IPCC was formed jointly in 1988 by the United Nations Environment Programme and the United Nations World Meteorological Organization. The IPCC brings together the world’s top scientists, economists and other experts, synthesizes peer-reviewed scientific literature on climate change studies, and produces authoritative assessments of the current state of knowledge of climate change. The Greenhouse Effect Q. What is the greenhouse effect? A. The Earth’s greenhouse effect is a natural occurrence that helps regulate the temperature of our planet. When the Sun heats the Earth, some of this heat escapes back to space. The rest of the heat, also known as infrared radiation, is trapped in the atmosphere by clouds and greenhouse gases, such as water vapor and carbon dioxide. If all of these greenhouse gases were to suddenly disappear, our planet would be 60°F colder and would not support life as we know it. Human activities have enhanced the natural greenhouse effect by adding greenhouse gases The Greenhouse Effect Some solar radiation is reflected by the earth and the atmosphere Most radiation is absorbed by the earth’s surface and warms it Some of the infrared radiation passes through the atmosphere. Some is absorbed and re-emitted in all directions by greenhouse gas molecules. The effect of this is to warm the earth’s surface and the lower atmosphere. Atmosphere Earth’s Surface Infrared radiation is emitted by the earth’s surface
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3 to the atmosphere, very likely causing the Earth’s average temperature to rise. These additional greenhouse gases come from burning fossil fuels such as coal, natural gas, and oil to power our cars, factories, power plants, homes, offices, and schools. Cutting down trees, generating waste and farming also produce greenhouse gases. Q. What are the most important
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This note was uploaded on 09/29/2010 for the course PHYS 17200 taught by Professor Gaboracsathy during the Spring '09 term at Purdue.

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CHEMISTRY READING ASSIGNMENT - Frequently Asked Questions...

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