GEOL 110 1st Edition Lecture 13Outline of Last Lecture II. Quiz 2 Study GuideOutline of Current Lecture III.Current LectureI. Climate ChangesA. The evidence for past climate conditions on Earth come primarily from measuring the abundances of the three isotopes of oxygen in foraminifera and other microscopic fossils in deep sea sediments.1. An isotope is a different version of an elements, that has the same number of protons but a different number of neutrons2. Foraminifera (also called forams) are microscopic organisms that live in the oceansand create tiny shells made of calcite. The oxygen isotope ratios in the calcite shells help scientists know what the temperature was at the time the shells were formed. 3. The O18/O16 ratio is low during periods of warm climate4. The O18/O16 ratio is high during periods of cold climate 5. Based on the past O18/O16 ratios, the climate today is unusually warm. However, there has been a cyclic shift in climate, from cold to warm throughout the past 2 million years. B. Why does the Global Climate change in cyclic patterns?1. Milankovitch Patterns – based on the elliptical orbit, the tilt, and wobble of the Earth. Where all of the low points combine, is where an ice age will occur. The shape of the Earth’s orbit controls solar energy.2. Other possible causes of climate change – position of continents, volcanic activity, formation of large mountain bells, burial of carbon, sunspot cycles, ocean currents, reflectivity of the earth, greenhouse gasses 3. There Is a decline in both temperature and greenhouse gas concentrations during glacial periods, and there is a rapid rise in both during deglaciation. The climate has been relatively stable during the last 10,000 years. These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.4. Sea level changes are also concurrent with climate changes. Warm climate = more water (because the glaciers melt) and cold climate = less water (because it is frozen in the