Climate change refers to changes in weather patterns over time due to an increase in temperature caused by greenhouse gases trapping heat in the atmosphere. The two main phenomena associated with climate change are the greenhouse effect and global warming. The greenhouse effect occurs when gases like carbon dioxide in the atmosphere prevent heat from escaping, similar to the way a greenhouse retains heat. Global warming describes the rise in average temperatures worldwide due to these increased greenhouse gases. If climate change continues unchecked, its effects will include further temperature increases, changes to ecosystems, and threats to human health and agriculture.