What is the Global Warming?

Global warming is an increase of the earth's temperature by a few degrees resulting in an increase in the volume of water which contributes to sea-level rise or increase in the average temperature of the earth's surface. It is a problem that humans made for the environment. All studies show that the inventions that man made, it is just producing pollutions. For example, factories, cars and AC. Some people are saying that the global warming is because of natural disaster like volcanoes and earthquakes. Scientists are saying that if we don’t stop polluting the earth, the results in the future will be harmful for the next generations. The reason to worry about global warming is the disasters that are happening every year in the world like Tsunami waves and Katrina Tornado. The last record, maybe 2007 was the hottest year. So that means a problem for the environment.