Behind the phenomenon of Global warming And Climate change There is an increase in greenhouse gases in our atmosphere. Greenhouse gases are gaseous compounds that can be absorbed in the atmosphere. Infrared radiation, Thereby trapping and retaining the heat in the atmosphere. By increasing the heat in the atmosphere, greenhouse gases cause the greenhouse effect, which ultimately leads to global warming.
Solar radiation and the “greenhouse effect”
Global warming is not a recent scientific concept. The basis of this phenomenon was elucidated in 1896 by Swedish physicist and chemist Svante Arrhenius over a century ago. Philosophical Magazine and Journal of ScienceWas the first to quantify the contribution of carbon dioxide to what scientists now call “”.Greenhouse effect“
The greenhouse effect occurs because the sun hits the earth with a large amount of radiation. Earth’s atmosphere In addition to visible light, in the form of ultraviolet (UV), infrared (IR), and other types of radiation invisible to the human eye. Ultraviolet rays have a shorter wavelength and a higher energy level than visible light, whereas infrared rays have a longer wavelength and a weaker energy level. About 30% of the radiation that hits the earth is reflected into space by clouds, ice, and other reflective surfaces. The remaining 70% is absorbed by the sea, land and atmosphere. NASA Earth Observatory..
When they get hot, the ocean, land, and atmosphere release heat in the form of IR thermal radiation, which is released from the atmosphere into space. According to NASA, it is this equilibrium of inflow and outflow that makes the Earth habitable, with an average temperature of about 59 degrees Fahrenheit (15 degrees Celsius). Without this atmospheric equilibrium, the Earth would be as cold and lifeless as the Moon, and as hot as Venus. The moon, which has almost no atmosphere, is about minus 243 F (minus 153 C) on the dark side. Venus, on the other hand, has a very dense atmosphere that traps solar radiation.average Venus temperature Is about 864 F (462 C).
The exchange of incoming and outgoing radiation that warms the earth is often referred to as the greenhouse effect, because agricultural greenhouses work in much the same way. Incoming short-wave UV light easily passes through the glass walls of the greenhouse and is absorbed by plants and the hard surfaces inside. However, weak long-wave IR radiation is difficult to pass through the glass walls and is trapped inside to warm the greenhouse.
How greenhouse gases cause global warming
Atmospheric gases that absorb radiation are known as “greenhouse gases” (abbreviated as GHG) because they are the main cause of the greenhouse effect. The greenhouse effect is one of the main causes of global warming.According to the most important greenhouse gases Environmental Protection Agency (EPA) is water vapor (H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O).
” oxygen (O2) is the second most abundant gas in our atmosphere, and O2 does not absorb thermal infrared rays, “Michael Daley, an associate professor of environmental science at Lasell University in Massachusetts, told Live Science.
Global warming and the greenhouse gases that cause it occur naturally — without them, the average surface temperature of the Earth would be a gel of 0 degrees Fahrenheit (-18 degrees Fahrenheit). However, the amount of greenhouse gases in the atmosphere has skyrocketed to harmful levels in recent history.
During the 20,000 years prior to the Industrial Revolution, atmospheric CO2 fluctuated between approximately 180 ppm during the glacial period and 280 ppm during the warm interglacial period. However, since the beginning of the Industrial Revolution in the 1750s, the amount of CO2 has increased by nearly 50%. NASA’s Global Climate Change PortalToday, CO2 levels are above 410ppm.
Fluorinated gas — a gas containing elements Fluorine Added — Created during an industrial process and is also considered a greenhouse gas. These include hydrofluorocarbons, perfluorocarbons and sulfur hexafluoride. Although they are present in the atmosphere at very low concentrations, they trap heat very effectively, resulting in a high “Global Warming Potential” (GWP) gas.
Chlorofluorocarbons (CFCs), which were once used as refrigerants and aerosol propellants until they were phased out by international agreements, are also greenhouse gases.
There are three factors that affect the extent to which greenhouse gases affect global warming: their abundance in the atmosphere, how long it stays in the atmosphere and its GWP. For example, water vapor is the most abundant greenhouse gas, but carbon dioxide is abundant in the atmosphere and has a relatively long life in the atmosphere of 300 to 1,000 years, so it has a greater impact on global warming. NASAOn the other hand, water vapor has a lifespan of less than 10 days in the atmosphere, according to a study published in 2020. Atmospheric science journal..
Methane is about 21 times more efficient at absorbing radiation than CO2, and despite staying in the atmosphere for only about 12 years, GWP is highly rated. United Nations Framework Convention on Climate Change (UNFCCC)Methane and other GHGs can trap more heat than CO2, but scientists still say that carbon dioxide is the main greenhouse effect because its warming effect lasts centuries longer than other effects. I think it’s gas.
Source of greenhouse gases
Some greenhouse gases, such as methane, are produced through agricultural practices, for example in the form of livestock manure. Others, such as CO2, result primarily from natural processes such as breathing, and from the burning of fossil fuels such as coal, oil and gas.
Another major source of CO2 is deforestationWhen trees are cut down to produce commodities and heat, the carbon normally stored is released. photosynthesisAccording to the process, it releases up to 4.8 billion metric tons of carbon into the atmosphere each year. World Resources Institute..
Forestry and other land-use practices can offset some of these greenhouse gas emissions. “Tree planting helps reduce the buildup of carbon dioxide in the atmosphere because growing trees sequester carbon dioxide through photosynthesis,” Daily told Live Science. “But forests cannot isolate all of the carbon dioxide we release into the atmosphere by burning fossil fuels, and we need to reduce fossil fuel emissions to avoid accumulation in the atmosphere.”
Globally, greenhouse gas emissions are a source of serious concern.by NOAA Climate.govOver the last 60 years, atmospheric CO2 has increased at an annual rate 100 times faster than previous natural increases. The world’s atmospheric CO2 levels were so high 3 million years ago, with temperatures up to 5.4 ° F (3 ° C) higher than before the Industrial Revolution. As a result of modern CO2 global warming, 2016 was the warmest year on record, with 2019 and 2020 being the next warmest, respectively. In fact, the hottest six years on record have all occurred since 2015. World Meteorological Organization..
Josef Werne, an associate professor of geological and planetary sciences at the University of Pittsburgh, said: “This will lead to major environmental changes and challenges for people around the world.”
The future of our planet
As current trends continue, scientists, government officials, and more and more citizens fear the worst. Impact of global warming — Extreme weather, rising sea levels, extinction of flora and fauna, Ocean acidificationA major climate change and an unprecedented social upheaval — will be inevitable.
To combat global warming caused by GHG, the U.S. government Climate Action Plan 2013. And in April 2016, representatives from 73 countries signed. Paris AgreementAccording to, an international agreement to combat climate change by investing in a sustainable low-carbon future United Nations Framework Convention on Climate Change.The United States Withdrawal from the Paris Agreement In 2017, it rejoined in late January 2021.President Biden’s administration has also set goals 50-52% reduction in US emissions (Emissions are regularly compared to 2005 emissions. US CO2 emissions peaked at nearly 6 billion tonnes.)
By 2020, global carbon dioxide emissions fell by 6.4% (13% in the US alone) — the annual rate hasn’t risen for the first time in decades. Nature reportedThis is partly due to reduced fossil fuel combustion. Switching from coal to natural gasHowever, mainly due to the forced suspension of economic, social and transportation activities corresponding to COVID-19 PandemicScientists expected that annual emissions would actually decline more than that, but emissions were higher as regulations were lifted in some countries and activity recovered towards the end of 2020. I have recovered.
To limit global warming to the 2.7 ° F (1.5 ° C) target set by the Paris Agreement, the world needs to reduce CO2 emissions by 7.6% over the next decade. United Nations Environment Program..
Researchers around the world are working hard to find ways to reduce greenhouse gas emissions and mitigate their effects. One of the potential solutions scientists are considering is to suck some of the carbon dioxide out of the atmosphere and bury it underground indefinitely.Proponents say carbon recovery and storage Technically feasibleHowever, the power of the market has hindered its widespread use.
Whether or not it is possible to remove carbon that has already been released from the atmosphere, greenhouse gas emissions must be stopped to prevent future warming. So far, the most ambitious effort to prevent global warming is the 2016 Paris Agreement. According to the United Nations, this non-binding international treaty aims to “pursue efforts to limit warming to well below pre-industrial levels of 2 degrees Celsius and further limit temperature rise to 1.5 degrees Celsius.” It is said. Each signatory to the Convention has agreed to set its own voluntary greenhouse gas emission limits and tighten them over time. Climate scientists said the emission limits promised under the agreement would not sustain warming up to 1.5 ° C or 2 ° C, but would improve over the “normal business” scenario.
Greenhouse gases: causes, sources, environmental impacts
Source link Greenhouse gases: causes, sources, environmental impacts