Global warming is the increase in Earth's near-surface air and ocean temperatures. The greenhouse effect is when water and carbon dioxide absorb outgoing infrared radiation, increasing the planet's temperature.
Greenhouse gases contribute to global warming. What is determined to be a greenhouse gas is any heat-trapping gas present in the Earth's atmosphere. The two most common greenhouse gases are water vapor and carbon. These gases help absorb infrared radiation and regulate the Earth's climate.
However, the increase in industrial production has increased the amount of greenhouse gases present in the atmosphere. The increase in carbon dioxide emissions has made it difficult for heat to escape the atmosphere. Heat enters the atmosphere through short wave radiation, heats the surface and exits as long wave radiation. However, the increase in greenhouse gases has increased the amount of long wave radiation. Long wave radiation is difficult to pass through the atmosphere, which in turn contributes to the warming effect.
In the early 1900s, the concentration of carbon dioxide in the atmosphere was less than 300 parts per million. This was before the industrial revolution. However, as of 2005, the amount of carbon dioxide present in the atmosphere measured 375 parts per million. While still on the low side, humans are contributing to the increase in carbon dioxide emissions through the burning of fossil fuels, such as coal and oil.