Impact Event as a Cause for Mass Extinction

Impact Event as a Cause for Mass Extinction   By Tom Newell    Part A          Possible Triggers for Mass Extinction Origin of Trigger Explanation Impact Events Extra-terrestrial Impact events, proposed as causes of mass extinction, are when the planet is struck by a comet or meteor large enough to create a huge shockwave felt around the globe. Widespread dust and debris rain down as well as forming a dust cloud, disrupting the climate and causing extinction on a global, rather than a local, scale. Climate Change Atmospheric Earths climate is not constant. Over geological time, the Earths dominant climate has gone from ice age to tropical heat and from steamy jungles to searing deserts. When such climate change occurs abruptly either in the form of a global warming or cooling animals and plants have no time to adapt so mass extinctions can occur. Flood Basalt Eruptions Land Flood basalt eruptions are a type of large-scale volcanic activity, both in terms of extent and duration, that can occur on land or on the ocean floor. A flood basalt may continue to erupt for tens of thousands possibly millions of years and the lava can cover hundreds of thousands of kilometres. Catastrophic Methane Releases Atmospheric Methane clathrate is an ice-like substance formed from water and methane in the sea bed, arctic lakes and permafrost. A temperature rise causes the methane in the clathrate to be released as gas. Global warming results and causes further clathrate heating and methane release. The resultant soaring temperature causes such stress to plant and animal life that mass extinction follows. Humans Land Because of the industrial lives we live, we are constantly emitting pollutants into the atmosphere. The chemicals being emitted are changing the composition of the atmosphere. This intern changes how our atmosphere affects our lives, from controlling temperature to blocking cosmic radiation. Part B It is believed that an impact event has caused a mass extinction in the past. Whats to say it wont happen again? An impact event capable of causing a mass extinction is when the planet is struck by an asteroid or meteor large enough to create a huge shockwave felt around the globe. When an impact event happens, the gigantic amount of kinetic energy is partly transferred from the large asteroid or meteorite travelling at high speeds, into the Earth. The rest of the energy is converted into heat and sound, creating pressure waves travelling radially outwards from its centre, similar to that of an atomic bomb. (physics.org, n.d.) As well as the blast from the impact, enormous amounts of dust and debris can be kicked up into the atmosphere blocking out sunlight and preventing the process of photosynthesis in plants from occurring, massively affecting the balance of ecosystems. If humans on the other side of the world from where the asteroid hit, survived the initial impact, they would mo st likely be killed by fiery rocks raining down from the sky and the heavily polluted dust filled atmosphere. Because of the polluted air, humans will not be able to breath properly and the Earths temperature will increase immensely. The huge dust cloud formed would block out light from the sun. If the asteroid lands in the ocean a colossal tsunami will form wiping out everything in its path and potentially wrapping around the world. An extensive earthquake will also be felt all over the globe after the impact, which will send structures crashing down and habitats will be destroyed. Obviously this chain of events would destroy the systems that we depend on for survival, from economic and infrastructure to the biological and fundamental building blocks of life, therefore causing a mass extinction. Part C Our planet is currently in the midst of its 6th mass extinction and unlike past mass extinction, caused by events like asteroid strikes and volcanic eruptions, humans are to blame! (biologicaldiversity.org, n.d.) It is human activities such as the emission of carbon monoxide (CO) and the clearing of wildlife that are killing our planet. Considerable amounts of CO are being emitted into the atmosphere every day because of our industrial lifestyle, but most people dont realise the harm that is being done to the environment. CO can be released into the air via a multitude of ways, but most commonly through your cars exhaust and the burning of fossil fuels in factories. Once CO is in the atmosphere it takes an oxygen molecule from the ozone molecules contained in the ozone layer in the attempt to make itself carbon dioxide (CO2). In doing this the ozone layer is damaged, therefore affecting its ability to protect us from the suns rays. Therefore, global warming occurs and the Earth will eventually be heated to a temperature at which humans and hundreds of thousands of other lifeforms can no longer survive. Another way in which humans contribute to mass extinction is through habitat removal. Not only does the clearing of habitants destroy the homes of animals, leaving them without a suitable place to live, but it also increases the amount of CO2 in the air. Trees and plants play a critical role in the ecosystem. They absorb carbon dioxide in the atmosphere and convert it into oxygen for us to inhale and use in respiration. By clearing wildlife, we are reducing the amount of trees and plants therefore increasing the amount of CO2 in the atmosphere. Global warming is no myth and there is plenty of evidence to prove its existence. According to three reliable international agencies, 2016 was crowned the hottest year on record. (www.abc.net.au, 2017) This was no coincidence either, 2015 and 2014 have been the 2nd and 3rd hottest years to be recorded. This is clear evidence that we are impairing the ozone layer and putting our lives in danger and contributing to the next mass extinction. It is hard to deny that humans are causing the Earth to undergo its 6th mass extinction when there is so much evidence to suggest so. The real question isnt whether or not humans are currently causing the planets 6th mass extinction event, but whether or not we can do anything to stop it. Or is it already too late? References ABC News. (2017). Hottest year on record: Australia needs to get heat smart. 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