How is global warming increased?
Global warming is increased by adding further greenhouse gases to the atmosphere, particularly carbon dioxide and methane. Average global temperatures rose by around 0.75 degrees during the twentieth century. The Kyoto Protocol set a target of limiting further rises to no more than 2 degrees Celsius, but the International Energy Agency now says that this target is no longer achievable.
What are the global problems of clearing forests and increased gas emissions from factories and motor vehicles?
Landslides happen because of increased rain softening the earth on the side of a mountain. They also occur where people have removed trees which anchored the earth. Removing trees has an effect on global warming, and one of the results of global warming is increased rainfall in some areas. So there is some connection.