Climate Change and Earth's History Quiz

Laurentide ice sheet

Weather is the state of the atmosphere over a short time, climate is weather averaged over a long period of time

Increasing concentrations of greenhouse gases in the atmosphere

<p>Global temperature trends</p> Signup and view all the answers

<p>Sun</p> Signup and view all the answers

<p>Changes in earth’s orbital motions</p> Signup and view all the answers

<p>Departure of the earth’s orbital ellipse from circularity</p> Signup and view all the answers

<p>The angle of the earth’s axial tilt with respect to the orbital plane</p> Signup and view all the answers

<p>Precession</p> Signup and view all the answers

<p>Tectonics and a warm/dry climate</p> Signup and view all the answers

<p>Over ~1000 years</p> Signup and view all the answers

<p>5-8 degrees</p> Signup and view all the answers

<p>Albedo</p> Signup and view all the answers

<p>Increase in albedo from snow and ice formation</p> Signup and view all the answers

<p>Ice-albedo feedback</p> Signup and view all the answers

<p>Volcanism spewed CO2 to the atmosphere, warming the planet</p> Signup and view all the answers

<p>Weather = State of the atmosphere over a short time Climate = Weather averaged over a long period of time (&gt;30 years) Global warming = Rise in global temperatures due mainly to increasing concentrations of greenhouse gases Climate change = Encompasses all types of changes in the atmospheric climate observed from regional to global scales</p> Signup and view all the answers

<p>Receding glaciers = Encompass both continental and alpine glaciers Last glacial maximum = Cold period in earth’s climate from ~26,000-20,000 years ago Laurentide ice sheet = Covers most of Canada at LGM and is a primary feature of the Pleistocene epoch Ice cores = Allow scientists to reconstruct global temperature trends by measuring oxygen isotopes in glacial ice cores</p> Signup and view all the answers

<p>Continental glaciers = Cover large land areas and include Greenland and Antarctica Alpine glaciers = Include examples like Franz Josef glacier in the South Island of New Zealand Last glacial maximum = Global temperature about 6 degrees C lower than today Laurentide ice sheet = Up to 3km thick at its maximum; several km’s covers the GTA</p> Signup and view all the answers

<p>Ice cores = Allow scientists to reconstruct global temperature trends by measuring oxygen isotopes in glacial ice cores Global warming = Mainly due to increasing concentrations of greenhouse gases in the atmosphere Last glacial maximum = Cold period in earth’s climate from ~26,000-20,000 years ago with a global temperature about 6 degrees C lower than today Climate change = Encompasses all types of changes in the atmospheric climate observed from regional to global scales</p> Signup and view all the answers

<p>Eccentricity = Measure the departure of the earth’s orbital ellipse around the sun from circularity Obliquity = The angle of the earth’s axial tilt with respect to the orbital plane Precession = The trend in the direction of the earth’s axis of rotation relative to a fixed distant point Milankovitch cycles = Glaciers advance and retreat through changes in earth’s orbital motions</p> Signup and view all the answers

<p>Paleocene-Eocene thermal maximum = Global temperature rose by 5-8 degrees, hot/wet climate dominated the entire planet Snowball Earth = Periods where entire planetary surface is frozen or glaciated Mediterranean Sea drying up = The sea closed off from the Atlantic and evaporated over ~1000 years Zanclean flood = Strait of Gibraltar opened up again at 5.3 Ma</p> Signup and view all the answers

<p>Ice-albedo feedback = Increased cooling which stabilizes snow and ice Carbon sink feedback = No carbon sink from atmosphere to surface ocean, leading to runaway freezing Volcanic CO2 release = Plate tectonics continues beneath the ice, and volcanism spews CO2 to the atmosphere, warming the planet Milankovitch cycles feedback = Cyclical variations in Earth’s orbit changing how much energy Earth receives from the sun</p> Signup and view all the answers

<p>Weather refers to the state of the atmosphere over a short period of time, while climate refers to the average weather conditions over a long period of time (&gt;30 years).</p> Signup and view all the answers

<p>The primary feature of the Pleistocene epoch is the Laurentide ice sheet, which covered most of Canada at the Last Glacial Maximum and was up to 3km thick at its maximum.</p> Signup and view all the answers

<p>The main cause of global warming is the rise in global temperatures due mainly to the increasing concentrations of greenhouse gases in the atmosphere.</p> Signup and view all the answers

<p>Ice cores help scientists to reconstruct global temperature trends by measuring oxygen isotopes in glacial ice cores, providing insights into paleoclimate and past climate conditions.</p> Signup and view all the answers

<p>The Milankovitch cycles are cyclical variations in Earth's orbit, including eccentricity, obliquity, and precession. These variations change how much energy Earth receives from the sun, leading to periodic variations in global temperature that correspond roughly to the ice core data.</p> Signup and view all the answers

<p>The 'snowball earth' refers to periods when the entire planetary surface is frozen or glaciated. The proposed mechanism for Earth getting out of this phase involves plate tectonics continuing beneath the ice, with volcanism spewing CO2 to the atmosphere, warming the planet.</p> Signup and view all the answers

<p>The Paleocene-Eocene thermal maximum refers to a period approximately 55 million years ago when global temperatures rose by 5-8 degrees, leading to a hot and wet climate dominating the entire planet, including the arctic regions.</p> Signup and view all the answers

<p>The Mediterranean Sea entirely dried up from about 5.9-5.3 million years ago, known as the Messinian salinity crisis. The sea closed off from the Atlantic and evaporated over approximately 1000 years, likely due to tectonics and a warm/dry climate. The Strait of Gibraltar opened up again at 5.3 million years ago, leading to the Zanclean flood.</p> Signup and view all the answers

<p>The ice-albedo feedback causes increased cooling which stabilizes snow and ice. As more heat is immediately reflected, the earth’s surface and atmosphere become cooler, leading to a runaway freezing known as 'snowball earth'. When snow falls on land or ice forms at sea, the increase in albedo causes increased cooling, which stabilizes snow and ice.</p> Signup and view all the answers

<p>The primary source of energy into the earth’s climate system is from the sun. Geophysicist Milutin Milankovitch first suggested the connection between glaciers and changes in earth’s orbital motions, which are now termed the 'Milankovitch cycles'.</p> Signup and view all the answers

<p>The 'Snowball Earth' refers to proposed periods in Earth's history where the entire planetary surface is frozen or glaciated. The evidence supporting this hypothesis includes glacial deposits at specific ages occurring globally, and even at equatorial paleolatitudes.</p> Signup and view all the answers

<p>The three main components of the Milankovitch cycles are eccentricity, obliquity, and precession. These variations change how much energy Earth receives from the sun, leading to periodic variations in global temperature that correspond roughly to the ice core data.</p> Signup and view all the answers

<p>The proposed mechanism for Earth getting out of the 'snowball earth' phase involves plate tectonics continuing beneath the ice, with volcanism spewing CO2 to the atmosphere, warming the planet. This process provides a carbon sink from the atmosphere to the surface ocean, leading to the thawing of the 'snowball earth'.</p> Signup and view all the answers

<p>The significance of the Paleocene-Eocene thermal maximum is the global temperature rise by 5-8 degrees, leading to a hot and wet climate dominating the entire planet. The planet eventually recovered from this period with enhanced biological activity, moving carbon from the atmosphere to the ocean floor.</p> Signup and view all the answers

<p>The disappearance of the Mediterranean Sea during the Messinian salinity crisis was likely due to tectonics and a warm/dry climate. The sea entirely dried up from about 5.9-5.3 million years ago, and the Strait of Gibraltar opened up again at 5.3 million years ago, leading to the Zanclean flood.</p> Signup and view all the answers

<p>The main causes of periodic variations in global temperature are the Milankovitch cycles, which include changes in earth’s orbital motions such as eccentricity, obliquity, and precession. These variations change how much energy Earth receives from the sun, leading to periodic variations in global temperature that correspond roughly to the ice core data.</p> Signup and view all the answers