Climate Change, Global Warming and Greenhouse Effect

2009-09-21 10:24 BJT

Recent Climate Change -- Surface Temperature Changes

According to the National Oceanic and Atmospheric Administration's (NOAA) 2008 State of the Climate Report and the National Aeronautics and Space Administration's (NASA) 2008 Surface Temperature Analysis:

·Since the mid 1970s, the average surface temperature has warmed about 1°F. ·The Earth’s surface is currently warming at a rate of about 0.29ºF/decade or 2.9°F/century.
·The eight warmest years on record (since 1880) have all occurred since 2001, with the warmest year being 2005.

Recent Climate Change -- Sea Level Changes

According to the Intergovernmental Panel on Climate Change (IPCC), the primary factors driving current sea level rise include:

·the expansion of ocean water caused by warmer ocean temperatures
·melting of mountain glaciers and small ice caps
·(to a lesser extent) melting of the Greenland Ice Sheet and the Antarctic Ice Sheet

-- The rate of sea level rise increased during the 1993-2003 period compared with the longer-term average (1961-2003), although it is unclear whether the faster rate reflects a short-term variation or an increase in the long-term trend. (IPCC, 2007)

While the global average sea level rise of the 20th century was 4.4-8.8 inches, the sea level has not risen uniformly from region to region.

-- Is the rate of sea level rise accelerating?

·The IPCC expresses high confidence that the rate of observed sea level rise increased from the mid 19th to the mid 20th century. During the 20th century, sea level rose at an average rate of  4.8 to 8.8 inches per century (1.2-2.2 mm/year). (IPCC, 2007)
·Tide gauges show little or no acceleration during the 20th century.
Satellite measurements estimate that sea level has been rising at a rate of 9 to 15 inches per century (2.4-3.8 mm/yr) since 1993, more than 50% faster than the rate that tide gauges estimate over the last century. (IPCC, 2007)

(Information can be found on

Editor: Liu Anqi | Source: