Climate Change
Download This Report | Climate Change | US EPA
Climate Change Indicators in the United States
Greenhouse Gases - Energy from the sun drives the Earth's weather and climate. The Earth absorbs some of the energy it receives from the sun and radiates the rest back toward space. However, certain gases in the atmosphere, called greenhouse gases, absorb some of the energy radiated from the Earth and trap it in the atmosphere. These gases essentially act as a blanket, making the Earth痴 surface warmer than it would be otherwise.
Weather and Climate - Climate is the average weather in a given place, usually over a period of more than 30 years. While the weather can change in just a few hours, climate changes occur over longer timeframes. Climate is defined not only by average temperature and precipitation, but also by the type, frequency, and intensity of weather events such as heat waves, cold waves, storms, floods, and droughts. Climate has natural year-to-year variations, and extremes in temperatures and weather events have occurred throughout history.
Oceans - Covering nearly 70 percent of the Earth's surface, the oceans store vast amounts of energy absorbed from the sun and move this energy around the globe through currents. As greenhouse gases trap more energy from the sun, the oceans will absorb more heat, resulting in an increase in sea surface temperatures, rising sea levels, and possible changes to ocean currents. These changes will very likely lead to alterations in climate patterns around the world. For example, warmer waters promote the development of more intense storms in the tropics, which can cause property damage or loss of life.
Snow and Ice - Snow and ice are an important part of the global climate system. Because snow and ice are highly reflective, much of the sunlight that hits these surfaces is reflected back into space instead of warming the Earth. The presence or absence of snow and ice affects heating and cooling over the Earth痴 surface, influencing the planet痴 energy balance.
Society and Ecosystems - The indicators in this report show that changes are occurring throughout the Earth's climate system, including increases in air and water temperatures, a rise in sea level, longer growing seasons, and longer ice-free periods on lakes and rivers. Changes such as these are expected to present a wide range of challenges to human society and natural ecosystems.
Our World is Changing: Looking Beyond 'the 2012' -
Our World is Changing: Looking Beyond 'the 2012' - YouTube
Is there a schmientist in the house?:anyone: