Global Warming and Climate Change What Are Global Warming and Climate Change? Global warming and climate change refer to an increase in average global temperatures. Natural events and human activities are believed to be contributing to an increase in average global temperatures. This is caused primarily by increase in 'greenhouse' gases such as Carbon Dioxide (CO2). What Is the Greenhouse Effect? The term greenhouse is used in conjunction with the phenomenon known as the greenhouse effect. Energy from the sun drives the earth's weather and climate, and heats the earth's surface In turn, the earth radiates energy back into space Some atmospheric gases (water vapor, carbon dioxide, and other gases) trap some of the outgoing energy, retaining heat somewhat like the glass panels of a greenhouse These gases are therefore known as greenhouse gases The greenhouse effect is the rise in temperature on Earth as certain gases in the atmosphere trap energy. Six main gases considered to be contributing to global climate change are carbon dioxide (CO2), methane (CH4) (which is 20 times as potent (强有力的) a greenhouse gas as carbon dioxide) and nitrous oxide (N2O), plus three fluorinated industrial gases: hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6). Water vapor is also considered a greenhouse gas. Many of these greenhouse gases are actually life-enabling, for without them, heat would escape back into space and the Earth's average temperature would be a lot colder. However, if the greenhouse effect becomes stronger, then more heat gets trapped than needed, and the Earth might become less habitable for humans, plants and animals. What Are the Impacts of Global Warming? For decades, greenhouse gases, such as carbon dioxide have been increasing in the atmosphere. But why does that matter? Won't warmer weather be nicer for everyone? Rapid Changes in Global Temperature A documentary aired on the National Geographic Channel in Britain on August 9, 2003 was titled What's Up with the Weather. it noted that the levels of carbon dioxide, for example, were currently at their highest levels in the past 450,000 years. Increased greenhouse gases and the greenhouse effect is feared to contribute to an overall warming of the Earth's climate, leading to a global warming ( even though some regions may experience cooling, or wetter weather, while the temperature of the planet on average would rise). However, it is the rapid pace at which the temperature will rise that will result in many negative impacts to humans and the environment and this is why there is such a world-wide concern. Extreme Weather Patterns Most scientists believe that the warming of the climate will lead to more extreme weather patterns such as: More hurricanes and drought Longer spells of dry heat or intense raja (depending on where you are in the world) Scientists have pointed out that Northern Europe could be severely affected with colder weather if climate change continues, as the arctic begins to melt and send fresher waters further south. It would effectively cut off the Gulf Stream that brings warmth from the Gulf of Mexico, keeping countries such as Britain warmer than expected In South Asia, the Himalayan glaciers (冰川) could retreat causing water scarcity in the long Super-storms Mentioned further above was the concern that more hurricanes could result. The link used was from the environmental organization WWF, written back in 1999. In August/September 2004 a wave of severe hurricanes left many Caribbean islands and parts of South Eastern United States devastated. In the Caribbean many lives were lost and there was i