Past Climate

• Paleoclimate is the study of past climates to provide context for current observations of global warming
• Ice cores and other proxies are used to determine past climate when instrumental records were not available
• Ice cores can be taken from ice sheets in Greenland or Antarctica to analyze isotope concentration of hydrogen and oxygen to understand past temperature trends
• Bubbles of air trapped in ice cores can be analyzed to determine past atmospheric composition, such as sulfuric acid indicating past volcanic eruptions
• Tree rings can indicate past climate change, with wider rings suggesting warmer and moister conditions and narrower rings indicating colder and drier conditions
• Fossils, corals, and tree pollen are also used as proxies to study past climate and environmental conditions
• The hockey stick diagram shows temperature change over time, with the medieval warm period and the little ice age being notable past climate events
• Paleoceanography involves analyzing sediments from ocean floor cores to understand past climate and sea water temperature changes
• Ice cores are used as proxies to determine past climate by analyzing isotope concentration of hydrogen and oxygen, air bubbles, sulfuric acid, and dust trapped in the ice
• Tree rings can indicate past climate change by looking at annual growth, thickness of rings, and harsh vs good growing conditions
• Fossils, corals, and tree pollen are other proxies used to study past climate by analyzing the types of species present and growth conditions
• The hockey stick diagram shows temperature change over time, indicating the medieval warm period, the little ice age, and the unprecedented warming in the 20th century
• Paleoceanography involves analyzing sediments from ocean floor cores to determine past climate and sea water temperature using oxygen isotopes and decomposed ocean life
• The JOIDES Resolution research vessel is used for analyzing sediment cores through ocean floor drilling to provide insights into changes in global climate over millions of years
• Isotopes are atoms that have differing numbers of neutrons in their nuclei
• We can determine the age of shells using ratios of oxygen isotopes.
• JOIDES stands for Joint Oceanographic Institutions for Deep Earth Sampling
• JOIDES Resolution is operated by Texas A&M University
• JOIDES Resolution began working for the Ocean Drilling Program in 1985
• JOIDES Resolution - In 2004, core samples recovered from the seafloor beneath the Arctic Ocean revealed that 55 million years ago the Arctic region had a subtropical climate