CO 2 – The amount of carbon dioxide in the atmosphere in parts per million (ppm).Calculated from modeling of the formation of the Earth’s core and tidal dissipation. Day length – The average annual day length.Luminosity – The energy from the sun received at the top of the atmosphere measured in percentage of the Suns current output.Largely inferred from oxygen isotopes in marine carbonates. Mean global air temperature – An average annual temperature for the entire planet.In regard to the elements that make up a climate history the key ones that appear in Earth Viewer that you will be working with in these activities are as follows… One of the goals of activity A on the following page is to familiarize yourself with the divisions of the calendar and the types of life common to each division. The latter is a term used by paleontologists to refer to the total number of fossils that have been discovered to date. As such it extends back in time to the Earth’s formation, nearly 4.5 billion years and it is divided into major segments on the basis of the appearance and disappearance of major types of life as evidenced by the fossil record. In a nutshell the calendar is a global timeline of the events that have shaped the current structure of the planet. In regard to earth history researchers customarily resort to something called the geologic calendar. The first is how earth scientists tell time, and the second is the major elements involved in recounting the Earth’s climate history. There are two pieces of background that are important for these activities. Earth Viewer from the Biointeractive program at the Howard Huges Medical Institute.How has the Earth’s climate changed during its history?.

Earth viewer