The term 'global warming' referrers to the rise in the average Earth's temperature over the years. This includes the temperature rise of the atmosphere and oceans. The Earth does go through natural warming and cooling periods over thousands of years, but what is known as 'global warming' today is much different. Global Warming is the rapid increase of temperature we have seen over the past few decades.
Researchers began documenting this in the late 19th century which provides us with many years of comparison. Scientists are almost 100% sure this is caused by us humans by increasing our greenhouse gas emissions. These emissions can come from automobiles, steel mills, and factories. Also, deforestation has contributed due to the reduction in plants producing oxygen and removing carbon dioxide.
For example, between 1906 and 2005 the Earth's average surface temperature has risen about 0.74C. This may not sound like a lot, but it is enough to cause weather and other climate issues. The years 2005 and 2010 have been the warmest years since scientists have been keeping track. Air temperatures have increased almost twice as fast as ocean temperatures. But, keep in mind that Ocean temperatures doesn't increase as fast because the oceans have a much larger heat capacity. Also, evaporation causes the oceans to lose a lot of heat.
Greenhouse gases are the root cause of global warming. To understand how they affect our planet, understanding the greenhouse effect is key. The greenhouse effect is the process of absorption and emission of infrared radiation by gases in the lower atmosphere. Without the Earth's atmosphere the planet would be extremely cold. Our atmosphere is what contains our planets heat.
Since the Industrial Revolution, greenhouse gases have increased dramatically. This is causing increased CO2, methane, CFCs and other bad gases. Some of these gases have increased almost 150% since the year 1750. The Industrial Revolution Era fits right into the this time frame as the root cause of these issues.
The suns solar activity was measured to see if it has affected the warmth of our planet over recent years. Scientists have determined that the Sun's output has not increased over the past 30 years. Therefore the Sun cannot be to blame for the increased warmth we have been experiencing. Climate models have also been used, but they have not been able to reproduce any significant change caused by the Sun.
Since one side affect of global warming is rising sea levels, several small islands are threatened. Also, low lying areas such as Bangladesh will continually be affected as global warming and greenhouse gases increase over the years. This could cause a lot of disruption within the country including increased homelessness. Since many goods are manufactured there, production issues would occur if a major catastrophe occurred.
In order to reduce the amount of climate change in the future, several efforts are in place to mitigate greenhouse gases. CFC's were banned from use in household products. Also, the latest 'green' movement has helped pressure companies to decrease their emissions and increase their utilization of recycled goods.