global warming essay
Effects of Greenhouse Gases (GHGs) on Global Warming
The main greenhouse gases, namely: Carbon dioxide (CO2); Methane (CH4); Nitrous oxide (N2O); Hydrofluorocarbons (HFCs); Perfluorocarbons (PFCs); and Sulphur hexafluoride (SF6). The impact of any GHG is based on the magnitude of the rise in its concentration, its duration in the atmosphere and the wavelength of radiation that is absorbed.
Excess CO2 comes mainly from burning fossil fuels — coal, oil and natural gas. Those fuels are used for everything from powering vehicles and generating electricity to manufacturing industrial chemicals. In 2016, CO2 accounted for 81 percent of the greenhouse gases emitted in the United States. Other chemicals are more effective at trapping heat in the atmosphere. But CO2 is the most abundant of the ones released by human activities. It also sticks around longest.
Some CO2 gets removed each year by plants as they grow. However, much CO2 is released during colder months, when plants aren’t growing. CO2 also can be pulled from the air and into the ocean. Organisms in the sea can then convert it into calcium carbonate. Eventually that chemical will become an ingredient of limestone rock, where its carbon can be stored for millennia. That rock-forming process is really slow. Overall, CO2 can linger in the atmosphere for anywhere from decades to thousands of years. So, Montzka explains, “even if we stopped emitting carbon dioxide today, we would still see warming from that for a very long time.”
Methane is the main component of natural gas. It’s also released from a host of biological sources. These include rice production, animal manure, cow digestion and the breakdown of wastes put into landfills. Methane accounts for about 10 percent of U.S. greenhouse-gas emissions. Each molecule of this gas is much better at trapping heat than is one of CO2. But methane does not remain in the atmosphere as long. It gets broken down as it reacts in the atmosphere with hydroxyl radicals (neutrally charged OH ions made from bound atoms of oxygen and hydrogen). “The timescale for methane removal is about a decade".
Carbon dioxide enters the atmosphere through burning fossil fuels (coal, natural gas, and oil), solid waste, trees and other biological materials, and also as a result of certain chemical reactions (e.g., manufacture of cement). Carbon dioxide is removed from the atmosphere (or "sequestered") when it is absorbed by plants as part of the biological carbon cycle.
CFCs and their more recent replacements are all manufactured by people. Many have been used as refrigerants. Others are used as solvents for chemical reactions and in aerosol sprays. Together, these made up only about 3 percent of U.S. greenhouse gas emissions in 2016. These gases are only removed when they get locked up in a high layer of the atmosphere. In this stratosphere, high-energy light bombards the chemicals, breaking them apart. But that can take decades.
Fluorine-based chemicals, such as CFCs, he notes, “are potent greenhouse gases, on a per molecule basis.” But releases of them are so low that compared to CO2, their overall impact is quite small. Reducing emissions of methane, N2O and CFCs will help slow climate change, Montzka notes. “But if we’re going to solve this [greenhouse gas] problem, we need to take care of CO2,” he says. “It’s contributing the most … and it has this extremely long residence time in the atmosphere.”
Nitrous-oxide (N2O) made up 6 percent of greenhouse gases emitted by the United States in 2016. This gas comes from agriculture, the burning of fossil fuels and human sewage. But don’t let its small quantity make you disregard N2O’s impact. This gas is hundreds of times more effective than is CO2 at trapping heat. N2O also can linger in the atmosphere for nearly a century. Each year, only about 1 percent of airborne N2O gets converted by green plants into ammonia or other nitrogen compounds that plants can use. So this natural N2O removal “is really slow" .
Hydrofluorocarbons (HFCs) are a group of industrial chemicals primarily used for cooling and refrigeration. HFCs were developed to replace stratospheric ozone-depleting substances that are currently being phased out under the Montreal Protocol on Substances that Deplete the Ozone Layer.
Many HFCs are very powerful greenhouse gases and a substantial number are short-lived climate pollutants with a lifetime of between 15 and 29 years in the atmosphere.
Though HFCs currently represent around 1% of total greenhouse gases, their impact on global warming can be hundreds to thousands of times greater than that of carbon dioxide per unit of mass. Assuming no new regulation, HFC consumption is projected to double by 2020, and emissions could contribute substantially to radiative forcing in the atmosphere by the middle of the century.
The Kigali Amendment to phase down HFCs under the Montreal Protocol entered into force in 2019. Under the amendment, countries commit to cut the production and consumption of HFCs by more than 80% over the next 30 years to avoid more than 70 billion metric tons of carbon dioxide equivalent emissions by 2050 -- and up to 0.5° C warming by the end of the century. Solutions are available to replace high-global warming potential HFCs in many sectors and reduce emissions.
HFCs are entirely man-made. They are primarily produced for use in refrigeration, air-conditioning, insulating foams and aerosol propellants, with minor uses as solvents and for fire protection. Most HFCs are contained within equipment, so emissions are the result of wear, faulty maintenance, or leakage at the end of a product’s lifetime.
HFCs have only been commercialized since the early 1990s, and their abundance in the atmosphere is currently small. They are, however, among the fastest growing greenhouse gases, largely as a result of increasing demand for refrigeration and air-conditioning, particularly in developing countries. Emissions of these gases are growing at a rate of 10-15% per year, which will cause a doubling every five to seven years.
HFCs are potent greenhouse gases that can be hundreds to thousands of times more potent than carbon dioxide (CO2) in contributing to climate change per unit of mass. A recent study concluded that replacing high-GWP HFCs with low-GWP alternatives could avoid 0.1°C of warming by 2050. Fast action under the Montreal Protocol could limit the growth of HFCs and avoid up to 0.5°C of warming by 2100.
HFCs can be most effectively controlled through a phase down of their production and consumption.
In addition to the direct climate benefits from HFC mitigation, a global HFC phase down could also provide indirect benefits through improvements in the energy efficiency of the refrigerators, air conditioners, and other products and equipment that use these chemicals. These efficiency gains could also lead to reduced emissions of CO2 and other air pollutants.
Perfluorocarbons are a group of human-made chemicals composed of carbon and fluorine only. Perfluorocarbons are powerful greenhouse gases that were introduced as alternatives to ozone depleting substances. PFCs replace chlorofluorocarbons (CFCs) in manufacturing semiconductors. They are also used as solvents in the electronics industry, and as refrigerants of some specialized refrigeration systems. In addition to being released during consumption, they are emitted as a by-product during aluminum production.
PFCs were added to Schedule 1 of CEPA in November 2005. Under subsection 90(1) of CEPA, a substance can be added to Schedule 1 of CEPA by the Governor in Council on the recommendation of the ministers of the environment and health if it is determined that a substance is entering or may enter the environment in a quantity or concentration or under conditions that:
(a) have or may have an immediate or long-term harmful effect on the environment or its biological diversity;
(b) constitute or may constitute a danger to the environment on which life depends; or
(c) constitute or may constitute a danger in Canada to human life or health.
Based on an analysis of the existing science, most notably documented in the Third Assessment Report (TAR) of the Intergovernmental Panel on Climate Change (IPCC) and in subsequent reports including the Fifth Assessment Report (2014), there is sufficient evidence to conclude that the principal greenhouse gases namely carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF6) constitute or may constitute a danger to the environment on which life depends. The addition of PFCss to schedule 1 of CEPA gives the Government the power to put in place a variety of preventative or control actions to control PFCss under that same Act. The reporting on releases of PFCs to the atmosphere is regulated under section 46 of CEPA and is required from large industrial and commercial facilities that meet a certain threshold for their combined emissions in CO2 equivalent of the six principal greenhouse gases.
There is more than one CAS number that applies to this group of substances.
Among all the greenhouse gases that exist, CO2 gets the most attention. Today, we bring a different perspective. Think about everything that you know about CO2 and multiply it by roughly 24,000. This is how much a gas called SF6 (sulphur hexafluoride) is stronger than CO2 in terms of global warming potential.
You read right: SF6 is the most potent greenhouse gas in existence with a global warming potential of 23,900 times the baseline of CO2. It means that one tonne of SF6 in the atmosphere equals 23,900 tonnes of CO2.
Even worse, SF6 is synthetic and it does not have a natural sink or any effective disposal methods, thus, when emitted, simply accumulates in the atmosphere. A cherry on top is that its atmospheric lifetime can be up to 3,200 years, which is well beyond CO2‘s 100-200- year lifetime. A gas 24k times more powerful than CO2 with a lifetime 16 times longer than CO2 is being released into our atmosphere, and very few people have the least idea.
We all know about greenhouses gases: as their name suggests they create the greenhouse effect by trapping heat in the atmosphere and increase the temperature on Earth. Small variations in the atmospheric concentration of these gases lead to significant changes in temperature that make the difference between ice ages when mammoths roamed planet Earth and the heat in which the dinosaurs dominated the planet. Greenhouses gases are normally characterised using two main indicators: Global Warming Potential – a relative measure of how much heat a greenhouse gas traps in the atmosphere; and the atmospheric lifetime – which measurees the lifetime of the gas in the atmosphere. The first indicator expresses itself in
CO2 equivalent (how much more or less greenhousy this gas is compared to
CO2) and the second is measured by the time it takes for a gas to disappear from the atmosphere.
Meet SF6, CO2‘s larger cousin
Among all the greenhouse gases that exist, CO2 gets the most attention. Today, we bring a different perspective. Think about everything that you know about CO2 and multiply it by roughly 24,000. This is how much a gas called SF6 (sulphur hexafluoride) is stronger than CO2 in terms of global warming potential.
You read right: SF6 is the most potent greenhouse gas in existence with a global warming potential of 23,900 times the baseline of CO2. It means that one tonne of SF6 in the atmosphere equals 23,900 tonnes of CO2.
Even worse, SF6 is synthetic and it does not have a natural sink or any effective disposal methods, thus, when emitted, simply accumulates in the atmosphere. A cherry on top is that its atmospheric lifetime can be up to 3,200 years, which is well beyond CO2‘s 100-200- year lifetime. A gas 24k times more powerful than CO2 with a lifetime 16 times longer than CO2 is being released into our atmosphere, and very few people have the least idea.
What is this crazy gas used for?
The energy industry is SF6’s biggest consumer– it consumes more than 80% of the gas. SF6 is mostly used inside switchgear – which is an absolutely essential component of any electricity grid. They are also used inside wind turbines, which means that neither wind energy as such, nor electricity, in general, can be claimed to be completely environmentally friendly.
SF6 is known for its isolating potential in electricity. As such, it is a favoured material for energy infrastructures. When it comes to total consumption, yearly SF6 emissions are equivalent to the annual CO2 emissions produced by approximately 100 million cars. Forecasts show that SF6 usage might grow, parallel to those industries, by 50% in 2030.
Why is SF6 not banned yet?
In 2014, the European Commission tried to ban SF6 (in the framework of its F-Gas Regulation No. 517/2014) but it did not affect its use in the electrical industry. The reason for this was that, at the time, there were no commercially viable SF6-free alternatives to the existing switchgear. This regulation will be revised in 2020 where new technologies on the market will be assessed to see if they could possibly lead to a reduction in the usage of SF6. In this context, the german company Nuvethra introducing a new technology and design method to remove altogether the need for this gas in electricity grids. With this new technique, the gas is replaced by… plain air!
What’s the effect on humans?
In its normal state SF6 is generally relatively harmless for human health. This is one of the reasons why it is not taken as seriously as it should be. In fact, if you google SF6, most of the content that you will find will be people having fun with it (because of its ability to bring even your voice on the Dark Side making you sound like Darth Vader). Fun, but not so much when you know the rest of this gas’ properties.
What is green muffler & its relation with Pollution 
Global efforts have been started for decreasing the emission of GHGs into the atmosphere. Of the many initiatives, the most important one is the Kyoto protocol declared in 1997, and came into effect in 2005, authorized by 141 countries. Kyoto protocol controlled 35 industrialised nations to reduce the emission of GHGs by the year 2012 to 5% less than the levels present in the year 1990.
The concentrations of greenhouse gases are not larger than oxygen and nitrogen, because neither has more than two atoms per molecule, and so they lack the internal vibrational modes that molecules with more than two atoms possess. Both water and CO2 have these "internal vibrational modes", and these modes of vibrations can consume and resend infrared radiation, which causes the greenhouse effect.
Impacts of Global Warming
1. Rising Sea level: Flooding of fresh water marshlands, low-lying cities, and islands with marine water is one of the major effects of global warming.
2. Changes in rainfall patterns: In some areas, droughts and fires happen, whereas in other areas, flooding takes place. This all is due to changes in rainfall pattern.
3. Melting of the ice peaks: Due to melting of the ice peaks, there is loss of habitat near the poles. Now the polar bears are considered to be greatly endangered by the shortening of their feeding season because of declining ice packs.
4. Melting glaciers: There is a significant melting of old glaciers.
5. Spread of disease: There is spread of diseases like malaria due to migration to newer and currently warmer regions.
6. Thinning of Coral Reefs due to warming seas as well as acidification because of carbonic acid formation: Almost one-third of coral reefs are now severely damaged by warming seas.
7. Loss of Plankton owing to warming seas: The large (900 miles long) Aleutian island ecosystems consisting of whales, sea lions, sea urchins, kelp beds, fish, and other aquatic animals, has now reduced due to loss of plankton.
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