GREENHOUSE GAS EMISSIONS AND GLOBAL WARMING 18.1 INtRODUctION (original) (raw)

The Greenhouse Effect & the Global Warming

Our planet Earth is facing a serious problem called Global Warming; the Earth's surface temperature is getting warmer and warmer, which is changing the Earth's climate everywhere with devastating affects on weather patterns across globe. It has a range of potential ecological, physical and health impacts, including extreme weather events (such as floods, droughts, storms, and heatwaves); melting of the ice caps causing sea-level rise; altered crop growth; and disrupted water systems and others. The climate change that we are witnessing is one of the greatest challenge facing humanity today. This may also put out many species at high risk of extinction, threatening the collapse of marine food chain and ecosystem. Shortage of food and water may trigger massive movements of people leading to migration, conflict and famine. Scientists generally agree that unless we address this problem now the situation will get worse and eventually will threaten the very life on earth. Scientist also generally agree that one major contributor to this global warming is the higher concentration of the greenhouse gas carbon dioxide CO2 in the atmosphere. This brings us to the important and interesting climatic phenomenon called the Greenhouse effect. Normally the Earth's atmosphere is very cold, so cold that normally life on Earth is not feasible. Today, it is possible for us to live on the Earth only because of what is called this Greenhouse effect where the so-called greenhouse gases. (GHG:water vapor, carbon dioxide, methane, nitrous oxide, and ozone.) in the atmosphere trap some of the Sun's radiation and radiate these back to the Earth. The process is called the Greenhouse effect, a term taken from the operation of the greenhouses. However, this is somewhat a misnomer; a greenhouse is not primarily warmed by the Greenhouse effect. Anyhow, our Earth is one of the few planets in our Solar system where this Greenhouse effect occurs. Other planets where this Greenhouse effect occur are Venus, Mars and Titan. Without this Greenhouse effect, the average temperature of the Earth's surface would have been very cold, about −18 °C (0 °F) rather than the present average of 15 °C (59 °F) which is comfortable for human life. This present average of 15 °C (59 °F) may be called the normal temperature of the Earth for human civilization. The Greenhouse effect works by preventing absorbed heat from leaving the earth through radiative transfer. Normally, the Earth receives energy from the Sun in the form of ultraviolet, visible, and near-infrared radiation. About 26% of the incoming solar energy is reflected back to space by the atmosphere while about 19% is absorbed by the atmosphere. Most of the remaining 55% energy is absorbed by the surface of the Earth and some are radiated back. Because the Earth's surface is colder than the Sun, it radiates back infrared light at wavelengths that are much longer than the wavelengths that were received. The atmosphere in turn radiates back some of this energy downwards depending on the strength of the greenhouse gases. This leads to a higher equilibrium temperature of the Earth surface than if the atmosphere were absent. The strength of the Greenhouse effect-how much extra energy it directs toward the Earth's surface-depends on how many greenhouse gas (GHG) molecules there are in the atmosphere. When GHG concentrations are high, they absorb a greater percentage of the Earth's infrared energy emissions. This means that more energy gets reemitted back toward the Earth's surface, raising its average surface temperature. We can think of the atmosphere as a heat-trapping grid surrounding the Earth. Water vapor, Carbon dioxide and other GHG are the solid bars of the grid while non-greenhouse1 gases (nitrogen and oxygen) are the open spaces between the grid bars. When infrared energy hits an open space of the grid, it escapes into outer space and dissipates; but when it hits a solid bar, the bar heats up and reradiates some portion of the energy back toward the Earth, raising its overall temperature. The more GHG molecules there are in the atmosphere, the more wide are the bars of the grid, shrinking the open spaces and making it harder for infrared energy to escape into space. The tighter the grid, the more energy it absorbs, and the hotter the Earth gets. We need to note that CO2 is not the biggest contributor of the GHG. Water vapor in the form of clouds is the greatest contributor with (32-76%). of these GHG. However, while we humans don't have any control on the natural process of formation of the water vapors (clouds) which are formed based of the surface temperature of the oceans, we humans have control in formation of the next biggest contributor of the GHG, the CO2 which contribute as much as (9-26%) of the GHG. Carbon dioxides also essential for life-animals exhale it, plants absorb and sequester it. There is a natural carbon cycle in the Earth's atmosphere. Carbon is absorbed from the atmosphere when photosynthesizing organisms such as plants, algae, and some kinds of bacteria pull it out of the air and combine it with water to form carbohydrates. It is returned to the atmosphere as CO2 when humans and other animals breathe it out, or when plants die and decompose. For the past thousands of years, this balance of intake and emission has kept the amount of carbon dioxide CO2 in the atmosphere constant. But in modern times, by burning an ever-increasing amount of fossil fuels, we are putting our finger on the scale, tipping the balance toward more CO2 emission. When we mine fossil fuels and burn them for energy, we are

Greenhouse Gases and Climatic Change

Integrated Science & Technology Program, 2013

Earth climate is determined by the equilibrium between the amount and distribution of incoming radiation absorbed from the sun and the outgoing longwave radiation emitted at the top of the atmosphere. Several atmospheric trace gases, including water vapor, carbon dioxide, methane, and nitrous oxide, absorb far more efficiently the longwave radiation than solar radiation. These so-called greenhouse gases increase the amount of energy available to the earth and keep it much warmer than it would be otherwise. Although water vapor (and clouds that contribute both to the greenhouse effect and cooling through the back refl ection of the incoming solar radiation) does not stay in the atmosphere more than ~2 weeks, most of the other greenhouse gases stay far more than 10 years. Anthropogenic use of fossil fuels, cement production, and deforestation already increased the atmospheric concentration of greenhouse gases and human activities also created new synthetic and powerful ones such as chlorofl uorocarbon. The corresponding positive radiative already contributed to the ~0.8 °C increase of the global surface temperature since 1850 and will act as the main climate driver for at least the next century. This chapter outlines the bases of the greenhouse effect and its impact on the earth climate from ~1850 to 2100.

Greenhouse Gas (GHG): The Runaway Effect-Earth’s Surface Heat Out of Balance

We are entering a new era of carbon and nitrogenous waste management. There is one particular biochemical phenomena of interest in this ‘tug-of-war’ for preserving life on Earth as we know it: the greenhouse effect. The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases (carbon dioxide, methane, water vapour, nitrous oxide), and is re-radiated in all directions. It is not a new phenomena.

Greenhouse Effect: Greenhouse Gases and Their Impact on Global Warming

The Greenhouse effect is a leading factor in keeping the Earth warm because it keeps some of the planet's heat that would otherwise escape from the atmosphere out to space. The study report on the Greenhouse gases and their impact on Global warming. Without the greenhouse effect the Earth's average global temperature would be much colder and life on Earth as we know it would be impossible. Greenhouse gases include water vapor, CO 2 , methane, nitrous oxide (N 2 O) and other gases. Carbon dioxide (CO 2) and other greenhouse gases turn like a blanket, gripping Infra-Red radiation Mini-review Article

The Effect of Greenhouse Gases on Earth’s Temperature

International Journal of Environmental Monitoring and Analysis, 2015

Global warming is affecting each and every part of the world. Due to global warming, the glaciers are melting which are causing the rise in the sea level. When the level of the sea rises, it causes danger to the people living in the low lying areas. So, this causes a big problem for people, plants and animals living on the earth or the ecosystem all in all. Pollution whether vehicular, electrical or industrial is the main contributor to the global warming. Everyday billions of vehicles release various gases into the atmosphere. This causes earth to warm up and increase its average temperature. The main purpose of the study is to collect information about a real problem that has negative impact on something in order to be able to reach solution or decrease its impact. This study shows that global warming is the result of many factors including greenhouse gasses which can be reduced if people behave in a responsible way. We can state that pollution is the link between the greenhouse gases released to the air and get trapped in the atmosphere which cause the raise in temperature known as global warming and leading to a huge bulk of negative consequences to all living and non-living creatures on Earth's surface.

Atmospheric greenhouse effect in the context of global climate change

Il Nuovo Cimento C, 1995

Great interest in the problem of the atmospheric greenhouse effect (not only in scientific publications, but also in mass media), on the one hand, and the undoubtfully overemphasised contribution of the greenhouse effect to the global climate change, on the other hand, motivate a necessity to analyse the role which the greenhouse effect plays as a factor of climate change. Significant progress in the analysis of existing observational data as well as succesful development of numerical climate modelling which have been achieved during the recent few years create a basis for a new survey of the atmospheric greenhouse effect in the context of global climate change. Such a survey is the principal purpose of this paper. After discussing a notion of the greenhouse effect, the detailed analysis of the present-day and paleoclimatic observational data has been conducted with subsequent consideration of numerical modelling results. A special attention has been laaid to assessments of the greenhouse warming vs. aerosol cooling. Then possibilities of the early detection of a greenhouse climate signal have been analysed and a few comments on the global climate observing system have been made with the general conclusion that more observations and further numerical modelling efforts are necessary to more reliably assess the contributions of various mechanisms to the observed global climate changes. It is only in the context of a coupled totality of significant climate forming factors and processes that the contribution of the greenhouse effect may be estimated.

The greenhouse effect - two contexts for greenhouse gas warming

The widespread explanations of the greenhouse effect taught to millions of schoolchildren are misleading. The objective of this work is to clarify how increasing CO 2 produces warming in current times. It is found that there are two contexts for the greenhouse gas effect. In one context, the fundamental greenhouse gas effect, one imagines a dry Earth starting with no water or CO 2 and adding water and CO 2 . This leads to the familiar "thermal blanket" that strongly inhibits IR transmission from the Earth to the atmosphere. The Earth is much warmer with H 2 O and CO 2 . In the other context, the current greenhouse gas effect, CO 2 is added to the current atmosphere. The thermal blanket on IR radiation hardly changes. But the surface loses energy primarily by evaporation and thermals. Increased CO 2 in the upper atmosphere carries IR radiation to higher altitudes. The Earth radiates to space at higher altitudes where it is cooler, and the Earth is less able to shed energy. The Earth warms to restore the energy balance. The "thermal blanket" is mainly irrelevant to the current greenhouse gas effect. It is concluded that almost all discussions of the greenhouse effect are based on the fundamental greenhouse gas effect, which is a hypothetical construct, while the current greenhouse gas effect is what is happening now in the real world. Adding CO 2 does not add much to a "thermal blanket" but instead, drives emission from the Earth to higher, cooler altitudes.

Greenhouse Gases -a Brief Review

https://www.ijrrjournal.com/IJRR\_Vol.4\_Issue.3\_March2017/Abstract\_IJRR004.html, 2017

Many investigators have expressed urgent need for pollution control measures which are effective and acceptable. Many harmful gases cause different health problems to human beings. Gases such as carbon dioxide, sulphur dioxide and hydrogen sulphide can be removed from exhaust gases by different methods. Greenhouse gases allow shortwave radiations to pass through the earth's atmosphere and heat the land and oceans. The long wave radiation emitted from earth surface cannot pass through atmosphere due to these greenhouse gases. This phenomenon leads to greenhouse effect. Vehicular and industrial pollution is main contributor to the greenhouse gases and global warming. Water vapor plays a very important role in energy transport by convection. Combination of solar radioactive heating and the strength of the greenhouse effect determine the surface temperature of a planet.