Environmental Business and Energy Information Services
Introduction to Climate Change and Global Warming
Climate Change is increasingly becoming an important consideration of our lives. Scientists believe that there are evidences all around us that the Earth's climate has been undergoing noticeable changes, largely attributed to anthropogenic activities (human activities providing changes in climate additional to the natural climate variability), particularly the industrial activities that commenced with the industrial revolution of the 1700-1800s in certain parts of the World. The human activities generate greenhouse gases which trap heat and increase the average temperature of our planet (global warming), eventually resulting in climatic changes.
Scientists (particularly the International Panel on Climate Change (IPCC)) believe that the global temperature has increased by close to 1oC in the last century and they believe that a further increase of between 1.1 to 6.4 oC (based on predictions from climate models) are possible during the next century. Global warming (i.e. increase in Earth's average temperature) could lead to sea level rises, natural disasters - the storms/flooding, the hurricanes, drought, wildlife extinction, water pollution etc.
What is Climate Change?
Weather is the state or condition of the atmosphere at a given time and place measured in terms of the atmospheric variables (i.e. temperature, humidity, air pressure, moisture, wind, cloudiness, precipitation (rainfall and snow) and sunshine). Weather changes from hour-to-hour, day-to-day, and season-to-season. The changes occur with the movement of air over the Earth surface and the resultant redistribution of heat and moisture. Climate is the average and/or the extremes (minimum and maximum) of the atmospheric variables over a time period (a decade or longer) for a given location. Climate is the expected, while weather is what you get. Weather changes rapidly, however, past data sets are used to estimate the climate of a particular location for a time period (a decade or longer).
Climate Change, at a location, is the observed differences in the averages and extreme values of the atmospheric variables when computed over two or more time periods (each time period being about a decade or longer) at the said location. If the climate is to be constant, there should not be observed differences in atmospheric variables observed in a point A between the time period 1932 and 1942 and another time period 1952 and 1962. Climate change represents a shift (upwards or downwards) in the magnitude of the atmospheric variables (temperature, precipitation etc) from the long established pattern for a given location. Several natural causes can lead to variability in climate. Climate variability due to natural causes, however, seems to even out over time (see IPCC graph of temperature variability below). However, several other human activities identified as causing climate change or enhancing the impacts of the natural climate change causes has been identified by the scientific reports to have caused substantial changes to our climate. As evident in the IPCC graph below, temperature seems to have risen by 4oC since the beginning of the industrial age. This increment is believed to be result from changes from human activities.
To understand how our climate is changing a body, the International Panel on Climate Change (IPCC) was set up in 1989 by two United Nations organizations: the World Meteorological Organization (WMO) and the United Nations Environmental Programme (UNEP). IPCC is a scientific body created with the mandate to provide the world with a clear scientific view on the current state of climate change and its potential environmental and socio-economic consequences. IPCC does not conduct any research nor does it monitor climate related data or parameters. IPCC reviews and assesses the most recent scientific, technical and socio-economic information produced worldwide relevant to the understanding of climate change. Thousands of scientists from all over the world contribute to the work of the IPCC on a voluntary basis.
Variations of the Earth's surface temperature: year 1000 to 2100 (Source: IPCC - Climate Change 2001 Synthesis Report)
Other Sources of Information: