GLOBAL WARMING
Over the past two hundred years, the air temperatures near the Earth’s surface have been rising. This phenomenon is called Global Warming. Studies have been undertaken to observe various weather phenomena. These include temperatures, precipitation, and storms. Further studies have been conducted to study the behavior of ocean currents and to check the atmosphere’s chemical composition. The studies indicate that since the Industrial Revolution, human activities have seriously contributed to climate change in an adverse manner. This is especially true for the last 50 years because the recordings show that the average global temperature has risen at the fastest rate during this period. What’s worse is the fact that this rate is only accelerating though this has been disputed many times. Claims have been made by many scientists that there has been a pause or slowdown in the rate of climate change or global warming. A contrary view suggests that if global warming is not curbed the earth’s temperature could rise by 10 degrees Fahrenheit in the next hundred years or so which would make it practically impossible for the survival of any life form on the planet.
So, how exactly does global warming happen? The first and foremost cause is the greenhouse effect. The greenhouse effect happens when pollutants (where Carbon Dioxide is the main culprit) in the air and greenhouse gases accumulate in the atmosphere and prevent solar radiation from escaping into space. Under normal conditions, solar radiation would rebound after hitting the earth’s surface but because it gets trapped due to the greenhouse gases, it causes the earth to get warmer.
Let’s discuss the causes of global warming in detail –
Greenhouse gases and global warming — It has already been mentioned that Carbon Dioxide is the main culprit because of which global warming is caused but there are other trace gases which prove just about as harmful. Methane and Nitrous oxide are the other greenhouse gases which contribute to global warming. The surface of the planet produces infrared radiation which is absorbed by these gases. This radiation is then emanated in equal proportions in all directions and the radiation discharged downwards reaches Earth’s surface and lower layer of the atmosphere which causes global warming. Moreover, of 100 units of solar radiation 70 units must go back into space for global warming to stop. But because the earth’s surface along with the atmosphere and clouds absorbs most of these 70 units so the entire 70 units are not released back into space. This upsets the thermodynamic equilibrium of the planet and causes it to become hotter.
Radiative forcing — Different climatic factors have a different level of influence on the amount of downward directed radiant energy targeted towards the earth’s surface and Radiative Forcing is an estimate of these levels. Further climatic factors are of two types — ones caused by human factors and ones caused by natural factors. Greenhouse emissions are an example of human factors while solar irradiance is an example of natural factors. Volcanic eruptions are factors of natural origin because the gases released and the ash produced during the same obstruct part of the solar radiation from the surface. Human factors come into play when greenhouse gases are released into the atmosphere. Radiative forcing can be both positive and negative. Positive radiative forcing happens when various climatic factors add to the heating of the earth’s surface while negative radiative forcing happens when various factors actually cause cooling of the same.
Human factors — Of the various factors influencing global warming, human factors deserve a special mention. Global surface temperatures have escalated in alarming proportions due to human activities. Since the industrial revolution emission of greenhouse gases has increased manifold. And that’s not all, humans have altered the land cover of the earth’s surface by changing the levels of aerosols and the ozone layer. Humans are burning fossil fuels all the time which emit greenhouse gases especially carbon dioxide. The billions of vehicles plying the roads of the world use gasoline and diesel which make a large contribution to the total amount of greenhouse gases released into the atmosphere. Production of electricity requires the burning of coal and oil which is a bigger contributor to global warming than vehicular traffic.
Water Vapor — It is a major contributor to global warming and though inherently it acts in a similar fashion as greenhouse gases do, it is different from them as it is regulated by air temperatures. It is both a cause as well as an effect of global warming. The rate of evaporation of water from the earth’s surface is wholly dependent on how hot the surface is. So as the earth gets hotter it leads to increased levels of evaporation which in turn leads to a greater concentration of water vapor in the lower atmosphere. This leads to higher absorption of radiation which further leads to the surface getting warmer.
Surface-level ozone — also known as low-level ozone is caused by air pollution. It is different from stratospheric O3 and is created when the stratospheric O3 sinks from the upper atmosphere to the lower atmosphere. Photochemical reactions which include the pollutant and the very deadly carbon monoxide also end up creating surface-level ozone. When the levels of surface-level ozone rise they can cause many health problems. Photochemical smog is another contributor to increasing surface-level ozone.
Nitrous oxides — Industrial activity is mainly responsible for the production of Nitrous oxide which behaves a lot like greenhouse gases. Nitrous oxide leads to increased levels of radiative forcing. It is also produced by biological reactions in soil and water. Industrial activities also produce halocarbons or fluorinated gases that behave in a similar fashion as Nitrous oxide as far as radiative forcing is concerned.
Aerosols — these create a negative radiative forcing and are almost as harmful as greenhouse gases when it comes to increasing surface temperatures. A direct impact of aerosols is that they absorb and reflect solar radiation but they have an indirect effect as well, that is they can change cloud formation as also properties of the clouds. Moreover, they act as surfaces where water vapor condenses to form a cloud. Aerosols when they are darker in color hinder the formation of clouds by soaking in the sunlight and eventually heating up the air that surrounds it. A unique characteristic of aerosols is that they can be carried long distances by wind.
The impact of Global warming will be catastrophic on the planet and all life will be affected if serious steps are not taken to counter this problem. Some of the effects of global warming are discussed below–
Melting of glaciers — The polar ice caps are reducing in size, the whole of the Arctic region is under threat with the glaciers melting and flowing into the oceans. This is leading to a rise in the level of the seas and the day is not far when excessive flooding will take place. The situation is very grim as this process cannot be reversed.
The threat of Climate Change — As the surface temperature of the Earth rises so does the evaporation levels and thus increased rains. Weather patterns become inconsistent and the flora and fauna are taken by surprise. Flora is extinguished and the fauna move to areas which they find more suitable, the result being the entire ecosystem is thrown out of balance.
Risk of droughts — We could soon be witness to extreme scenarios in different parts of the world. While the Savannah may be experiencing floods, the USA might be experiencing severe droughts. Heatwaves and no precipitation will cause millions of trees to disappear. Africa in particular will be home to droughts as large-scale evaporation takes place.
Risk of multiple diseases — With global warming comes increased rains and this will further lead to the spread of water borne diseases like malaria and dengue. Heatwaves are surely going to deal a massive blow to all life on the planet.
Frequent Hurricanes — As the temperature of the earth soars so does the temperature of the water in the seas and oceans and as it does so it heats up the surrounding air which is what creates hurricanes. As a result of global warming, hurricanes will be stronger and more frequent.
Agriculture will be adversely affected — With the rise in temperatures, the survival of the plants will be at high risk. The food chain starts with plants and crops, so when they start to die food shortage is surely going to happen. This can even lead to wars between countries experiencing a shortage of food and those that are relatively better stocked.
Risk of Wildfires — With every passing year the summers are getting warmer and the levels of carbon dioxide are going up as well, the result being wildfires are happening a lot more frequently nowadays as compared to yesteryears. Both humans and wildlife are endangered.
Changes in duration of seasons — Irregular weather patterns are emerging due to global warming. We all love the spring season but nowadays there is no telling if it will happen sooner and shorter or later and longer. Studies suggest that spring happens ten days sooner than what it used to in the past.
Adversely affects coral reefs — the presence of coral reefs in the oceans is fast diminishing because of the rise in the temperature of the oceans. Once coral reefs become extinct many ecosystems will disappear.
Hazardous to health — With global warming comes the risk of more and more carbon dioxide being trapped in the atmosphere. This leads to unhealthy air being inhaled by all life forms and this further leads to respiratory diseases that are difficult to cure.
Adversely affects the quality of life — As has already been discussed global warming causes air that is difficult to breathe and on the climate front it causes severe heat waves. This seriously deteriorates the quality of human life because even simple recreations like taking a walk in the outdoors or gardening become humdrum affairs.
Economic collapse — As mentioned before the food industry is sure to get hit on a big scale. When there is not enough food the manufacturing industry will also be affected adversely. This would lead to economies all over the world collapsing. The biggest challenge in the near future would be fighting hunger.
It is heartening to see that many countries realize the potential dangers of global warming and have taken steps to try and reduce the same. One such step was the Copenhagen Accord of 18th December 2009. 111 countries came in support of the Copenhagen Accord. They had agreed to collectively reduce global warming pollution. They aim to hold temperatures to less than 2 degrees Centigrade. They had agreed to file reports on their emission levels and also report their progress towards a reduction in emission commitments every 2 years according to guidelines agreed upon on an international basis. They also agreed to make provisions for international consultations and analysis. They had further agreed to provide support for addressing deforestation which is responsible for 15 percent of the world’s emissions. As much as dollar four billion had been pledged over a period of 3 years to support this effort.
Leaders in the USA have recognized the need for clean transportation to protect public health. They are going all out to augment the electric car market. They are focusing on the clean energy economy and battling the federal efforts to quash the same. Wind employment has grown in the USA and solar jobs have gone up too.
On a global scale, the United Nations Conference on Climate Change in Paris saw 195 countries agreed to cut pollution levels and fixed a goal to prevent the average global temperature from rising more than 1.5 degrees above preindustrial times. To make this deal a reality, the Obama administration pledged dollar three billion to the Green Climate Fund. According to the terms of the Paris agreement, the countries participating in the same would meet once every 5 years, starting in 2020 to discuss their plans for cutting Carbon Dioxide emissions. 2023 onwards they will make their progress on the same public.
Finally to sum up all of the above said we need to answer some very vital questions. What will we and what can we do to curb this warming of the planet for which we have only ourselves to blame. How will we cope up with some of the irreversible damage that has already been done? It is reassuring to know that there is enough awareness around the subject and that steps are already underway to tackle the threat of human extinction due to global warming. The turnaround has started but is enough being done to completely rid the planet of the various harmful effects that global warming has on it. Carbon dioxide emissions have decreased globally due to new energy-efficient technologies and cleaner fuels being used in factories all over the world. But we’ve managed only the tip of the iceberg so far. Underdeveloped countries are still resorting to old technologies and this has only increased the menace. There is a need to bolster the power plants with new technology, produce cleaner electricity, and burn less gasoline when we travel. We have done the right thing as far as coming up with the solutions is concerned but we have to ensure that these are actually put into practice and widely adopted.
Keywords used in the article — global warming, causes of global warming, greenhouse gases and global warming, impact of global warming, effects of global warming
