Question: What can produce a new glacial period?

Hi tibi29:
Glacial periods occur by natural cycles in the orbit of the Earth. These cycles occur every 24,000, 40,000, and 100,000 years. When the cycles align, there is the greater potential to have glacial periods. In addition, a very important component is the concentration of carbon dioxide in the atmosphere. Carbon dioxide is the most important greenhouse gas in the atmosphere because it is abundant. When there are low concentrations, you should expect colder climate. Weathering, erosion, and the distribution of continents can lower the concentration of carbon dioxide in the atmosphere and store the carbon dioxide within minerals in rocks in the ocean. This is one way in which carbon dioxide will be reduced from the atmosphere and trigger a glacial period. Ongoing scientific work continues to improve our knowledge of what produces these periods.