About: Causes and Effects of volcanic eruption
Introduction
It is already known that volcanic eruption can cause cooling effects on earth by throwing sulfuric acid droplets and ash particles into the atmosphere that eventually block sunlight. Volcanic eruption ejects sulfur dioxide gas into the atmosphere. Sulfur dioxide mixed with water resulting into sulfuric acid haze thus forming volcanic winter that reflect and block incoming sunlight. This causes cooling effect in the earth. Now research also has unfolded that the reverse is true. It is evident that volcano eruption can cause increased in global temperature that eventually cause global warming. Volcanoes can cause the global climate over several years, though it must be accompanied by volcanic eruption of sulfate aerosols into the atmosphere. This paper aims to examine how huge volcanic eruptions can cause impact of short-term climatic cooling. The paper also studies effects of volcanic eruption on environment and how prevalent volcanism may lead to global warming.
Effects of volcanic eruption on environment
Volcanic eruptions cause many threats to million of people across the world. In the current world, there is an estimate of 500 active mountains on earth (Brown, 2001). Annually, there are about 11 to 39 volcanic eruptions. Volcanic eruptions cause dangerous impacts on health, climate and environment. Such impacts are hazardous to human survival and are detrimental to economic and social conditions. Harmful gases such as carbon dioxide, methane, sulfur dioxide, hydrogen chloride, hydrogen chloride, hot steam and magma, and other organic compounds. Their harmful impacts depend on the distance from which volcanoes are located, gas concentration as well as magma viscosity. Others perils include mud flow, toxicant volcanic dust particles, hot stream and poisonous gases.
Problems associated with these hazards include respiratory problems, death, injuries, skin and eye problems, destruction of communication and transport network, psychological effects, power outage, destruction of buildings, sewage disposal problem, water supply system disruption, and human displacement. Other negative impacts include crop damage, climate change, lack of rainfall, unsafe and water quality. Impacts of volcanic eruptions are dangerous because they cause total destruction. Unfavorable health impacts can be partialiy prevented by applying safety measures in a timely manner.
Huge volcanic eruption can cause short-term climatic cooling
During 15th June 1991 there was volcanic eruption at Mount Pinatubo in Philippines. An approximated 25 million tons of ash and sulfur particles were blown into the atmosphere. Eruptions trigger widespread damage and many people lost their lives. Solid and gases particles blasted into the stratosphere move around the world for about three weeks. Volcanic eruptions have effect on global climate, minimizing the quantity of solar radiation that reaches the surface of the earth, reducing temperature in the atmosphere, and altering the circulations of the atmospheric patterns. Large scale volcanic events may occur for some few days, but the massive outpouring of ash and gases particles can affect climate patterns for several years (Cavendish, 2005). Sulfuric gases are changed into sulfate aerosols that contain an estimate of 75% of sulfuric acid. Volcanic eruption can cause climatic impact on the earth both for long and short term. For instance, Mount Pinatubo erupted during 1991 and caused reduction of average global temperature for about two and half years.
Cold temperature had negative impact in Europe and North America when Mount Tambora erupted during 1815. This eruption caused famine and crop failure. Volcanologists hold a belief that balance of mild climate in the world for several million years is maintained by occurrence of the continuous volcanic eruptions (Withers, 2007). Volcanoes have impact on climate because dust and gases particles are blasted into the atmosphere whenever volcanic eruption occurs. The impact of the volcanic dusts and gases may cause cooling or warming the surface of the earth. This depends on the manner in which sunlight react with the volcanic gases and dusts.
James (2007) presents that volcanic dust erupted into the atmosphere have effect of causing cooling on temporary basis. The quantity of cooling relies on the quantity of the dust particles into the air. The duration in which cooling take place relies on the quantity of the dust particles. Particles thrown in the air and remain close to the mountain; such particles do not have big impact on the climate. Tiny ash-dust particles blasted into the atmosphere remain there for some days and cause cooling and darkness under the ash cloud. Rain and water available in the lower atmosphere rapidly wash away the tiny ash-dusts. Nevertheless, dusts thrown into the upper dry part of the atmosphere can stay there for several weeks or months before eventually washed away. Such dusts normally cause cooling and block sunlight from reaching parts of the world.
Volcanic eruption causes release of huge quantity of sulfur compounds such as sulfur dioxide or sulfur oxide have stronger impact on climate than dusts ejected into the atmosphere. Sulfuric compounds are made of gases which easily move into stratosphere (upper dry part of atmosphere). Once sulfuric compounds are in stratosphere, they mix with available water to make up sulfuric acid that is visible as tiny droplets (Wilson and Drury, 2000). Such tiny droplets are small light particles that reflect sunlight and eventually grow bigger. Though the droplet become large and fall in the earth, it takes time for example several years or months for the droplets fall due to the dry impact of the stratosphere. Cooling impact can be caused by sulfur droplets; this effect may happen after two years from the time eruption took place. Sulfur hazes are known to cause global cooling effect which happened when mount Tambora and Pinatubo erupted. A satellite traced, after several months, the presence of the sulfur that Pinatubo produced. This is a continuous group of haze that surrounds the whole globe.
During 1st January 2008, Llaima volcano erupted sulfuric hazes (sulfuric dioxide) into the atmosphere and caused cooling effect after several months. This eruption caused smoke (volcanic ash) skyward. However, there was no damage or injuries claimed. The eruption caused tourists to evacuate the volcano’s base. Volcano Llaima released cloud of sulfur dioxide into the atmosphere. At first the cloud of sulfuric acid moved from one place to another while growing to become bigger. According to Cavendish (2005), the image of this cloud was red that showed that sulfuric acid was concentrated. Sulfuric dioxides, which were erupted from the volcano mountain, mixed with water and eventually developed sulfuric acid hazes. Sunlight was reflected away from earth by this haze whose impact caused a cooling effect on surface of the earth. The magnitude of eruption at Mount Pinatubo was greater than Llaima, but both eruptions released clouds of sulfuric dioxides that combined with water to form sulfuric acid which caused cooling impact on climate. While volcanic dusts and particles released on the lower part of the atmosphere are washed away within fewer days due to impacts of gravity and rainfall, volcanic dusts thrown into the stratosphere may stay there for many years and slowly spread over the globe.
Widespread volcanic eruption cause global warming
Volcanic eruptions have potential of affecting global climate for long time period. Increased volcanic eruptions can release large amount of greenhouse gases that may cause global warming (Milne, 2002). Nevertheless, the cooling effect caused by sulfuric dioxide may counter the effect of the greenhouse warming. The resulting climate change is unpredictable. This will depend on the kind of volcanic activity. Volcanoes produce more carbon dioxide than amount that human beings produce. Immense volcanic eruption happened in a place known as the (CAMP) Central Atlantic Magmatic Province ejected large quantity of gases and lava such as methane, sulfur, and carbon dioxide.
This sudden rise of gases and dusts into the atmosphere increase global warming as well as acidification in water bodies like oceans that killed many animals and plants (Gunn, 2001). Volcanic eruptions have caused increased emission of gases that trap heat in the atmosphere. Since 2000, 17 volcanic eruptions have taken place including Merapi (Indonesia) , Kasatochi (Alaska) , Nabco (Eritrea) and others have ejected sulfur that have caused cooling effect, though climate scientists largely ignored these effects for several times until they performed thorough investigation to verify their findings. Volcanic eruptions cannot be predicted but when they happen they block global sunshine for several years. Volcanic eruptions account for 15 percent global warming. Temperature increase happens due to emissions of greenhouse gases in the atmosphere.
Formation of HCI (halide acid) has effect of destroying ozone layer. When it is formed, halide acid reacts with ozone though some of them are washed away by rain. Satellite data showed that about 15 percent ozone was lost when mount Hudson and Mount Pinatubo erupted. It is evident that volcanic eruption contributes an influential role in minimizing ozone layer. Nevertheless, this as an indirect role and it cannot be explained that volcanic HCI directly cause reduction of ozone levels. Brown (2001) says that eruption particle known as aerosols is attributed to offer surface upon which chemical reaction occur. Though volcanic aerosols offer a catalytic ground for ozone depletion, major cause of ozone destruction are CFCs that are produced by human activities. Climate scientists predict that ozone levels recover because United Nations has restricted chemicals such as volcanic HCI, CFCs and others from destroying ozone. Nevertheless, volcanic eruption talking place in the future will interfere with the recovery process of ozone levels. Depletion of ozone causes global warming. Through this process it can be justified how volcanic eruption cause global warming.
Relationship between global warming and cooling effect
Volcanic eruption can increase global warming by producing carbon dioxide into the atmosphere. Nevertheless, greater quantity of carbon dioxide is produced into the atmosphere due to human activities taking place annually than through volcanic eruptions. Volcanic eruption produces greenhouse gases into the atmosphere that cause global warming. Global warming effect caused by volcanic eruption has greater impact than the cooling effect caused erupted dusts in the stratosphere. However, it is explained the cooling effect helps to reduce global warming. Greenhouse warming was noticed as a threat to the earth since 1980. Cooling effect caused by volcanic eruption that took place at Mount Pinatubo (1991) and Mount El Chichon (1982) played a crucial role of reducing global warming. Without these cooling effects, global warming could have been more profound.
Volcanic eruption increase the haze effect more than greenhouse effect so that to reduce average global temperature. Milne (2002) views that many years back, scientists believe that volcanic eruption caused the haze effect as a result of suspended dust particles in the stratosphere that would block sunlight. Nevertheless, this perception was later changed during 1982 when El Chichon (Mexico volcano) erupted. During 1980, Mount St. Helens erupted and reduced global temperature by about 0.1C. El Chichon erupted and further reduced global temperature by five times lower. Mount St. Helens ejected more quantity of ash particles in the stratosphere. El Chichon ejected large amount of sulfur dioxide in the atmosphere. Sulfur mixed with water form cloud droplets of sulfuric acid. Such droplets accumulate in size for many several years and they are able to reduce temperature by absorbing sunlight radiation and reflect it back to the universe or space.
Conclusion
Volcanic eruption can cause three climate effects such as ozone depletion, cooling effect and global warming. Eruptions release dusts and particles that block sunlight and therefore causing short term cooling effect on earth. The particles may remain in the atmosphere for several years. Eruption also may release carbon dioxide that can stay in the atmosphere for several years. The impact of carbon dioxide in the atmosphere causes greenhouse effect that triggers global warming. These two phenomena are not major ways in which climate change is caused, but they have great impact on climate.
References