Scientists have warned that the world's climate is changing rapidly due to human-caused greenhouse gas emissions, primarily from burning fossil fuels. The warming climate is causing glaciers to melt and stronger storms to form. While climate has changed naturally in the past, current changes are occurring faster and are driven by human activity. The climate refers to long-term weather patterns over years in a given location, while weather describes short-term outdoor conditions. Greenhouse gases in the atmosphere, such as carbon dioxide, trap heat and maintain the Earth's warm temperature.