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Melting polar ice caps
- 1. ERASMUS+ OUR PLANET OURFUTURE IES ALFONS XIII CABANES APRIL 2019 the melting of the polar ice caps
- 2. INTRODUCTION: In the past,the melting of the polar ice caps was a natural process. The periods of glaciation and melting have been natural until the end of the 20th century. But today, the polar sheets are melting at an increasing rate. Studies carried out in the year 2013, estimated that the Polar regions would need more than 5,000 years for all the ice to melt and the sea level would rise about 66 meters. Among other reasons, the large amount of carbon dioxide that we produce and emit into the atmosphere raises the levels of global warming in our planet.
- 3. WHAT ARE THEPOLES? What is Polar ice? It's fresh water coming from a variety of sources. It forms, develops and melts into the ocean. On the other hand, icebergs, glaciers and ice platforms float in the ocean, but originate on land. Why is it important? Arctic and Antarctic ice keeps the polar regions cold and helps to moderate the global climate. The sea ice has a shiny surface, and 80% of the sunlight that affects it is reflected back into space (albedo). As the ice melts in the summer, the dark surface of the dark ocean is exposed, which instead of mirroring absorbs 90% of sunlight. The Oceans are warming up, and the Arctic temperatures are rising even higher.
- 4. CAUSES OF THAT: Temperaturechanges have led to changes and several phenomena that are currently very well known. Emissions of polluting gases make the greenhouse effect raise by changing the temperature of the oceans and seas. Thus, affecting the poles. Carbon dioxide is a main cause for this effect. The greenhouse effect makes the average temperature on Earth ideal for life. However, the uncontrolled increasing of the temperature is becoming a main issue nowadays.
- 5. CONSEQUENCES: Decreased Albedo: Albedois the percentage of solar radiation that the Earth's surface reflects or returns to space. One of the consequences of the disappearance of ice sheets would be the reduction of albedo from 0.6% to 0.1%. This leads to a greater heat-up in the Earth's surface and therefore an increase in global temperatures. Sea level Rise: The Summer ice has only a quarter of the volume it had in the seventies of the last century. This causes the thawing water to circulate through the caps until it ends up in the sea, increasing its level.
- 6. Methane Emissions: Thesediments that we find in the marine permafrost have large amounts of methane retained, so their thaw would generate the release of large columns of methane. Methane has a greenhouse effect 23 times higher than carbon dioxide, so its release into the atmosphere would further increase global warming. Jet Stream : This jet stream is slower than before, because the temperature difference between the lower latitude waters and the Arctic waters has been reduced. The fact that the jet stream is slower allows local meteorological systems to be prolong from a single phenomenon such as droughts, floods, heat waves, etc. Ocean Conveyor Belt : It is a current in which the masses of hot water circulate in the direction of the Arctic and as they go cold they become more salty and dense. This increase in density causes the water masses to sink and circulate again to lower latitudes.When they reach the Pacific, they again get warmer and less dense, they return to the surface .
- 7. NUMBERS: THAW IN THENORTH POLE in september (the end of the summer in North Hemisphere) THAW IN THE SOUTH POLE in march (the end of the summer in South Hemisphere) ICE IN THE POLAR CAPS – Average length in the last 30 years
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- 12. Thank you verymuch for giving us the opportunity to live this experience and for your attention.