Greenhouse Effect And Global Warming Pdf
Earth's energy budget The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without its atmosphere. If a planet's atmosphere contains radiatively active gases (i.e., ) they will radiate energy in all directions. Part of this radiation is directed towards the surface, warming it. The intensity of the downward radiation – that is, the strength of the greenhouse effect – will depend on the atmosphere's temperature and on the amount of greenhouse gases that the atmosphere contains. Earth’s natural greenhouse effect is critical to supporting life.
Human activities, mainly the burning of fossil fuels and clearing of forests, have strengthened the greenhouse effect and caused. The term 'greenhouse effect' arose from a faulty analogy with the effect of sunlight passing through glass and warming a. The way a greenhouse retains heat is fundamentally different, as a greenhouse works mostly by reducing airflow so that warm air is kept inside.
Main article: The existence of the greenhouse effect was argued for by in 1824. The argument and the evidence were further strengthened by in 1827 and 1838 and reasoned from experimental observations by in 1859, who measured the radiative properties of specific greenhouse gases. The effect was more fully quantified by in 1896, who made the first quantitative prediction of global warming due to a hypothetical doubling of atmospheric carbon dioxide. However, the term 'greenhouse' was not used to refer to this effect by any of these scientists; the term was first used in this way by in 1901. Mechanism Earth receives energy from the Sun in the form of, and radiation. About 26% of the incoming solar energy is reflected to space by the atmosphere and clouds, and 19% is absorbed by the atmosphere and clouds.
Most of the remaining energy is absorbed at the surface of Earth. Than the Sun, it radiates at than the wavelengths that were absorbed. Most of this thermal radiation is absorbed by the atmosphere and warms it. The atmosphere also gains heat by sensible and latent heat fluxes from the surface. The atmosphere radiates energy both upwards and downwards; the part radiated downwards is absorbed by the surface of Earth. This leads to a higher equilibrium temperature than if the atmosphere were absent.
The spectrum for direct light at both the top of Earth's atmosphere and at sea level An ideal thermally conductive at the same distance from the Sun as Earth would have a temperature of about 5.3 °C. However, because Earth reflects about 30% of the incoming sunlight, this idealized planet's (the temperature of a blackbody that would emit the same amount of radiation) would be about −18 °C. The surface temperature of this hypothetical planet is 33 °C below Earth's actual surface temperature of approximately 14 °C. The basic mechanism can be qualified in a number of ways, none of which affect the fundamental process. The atmosphere near the surface is largely opaque to thermal radiation (with important exceptions for 'window' bands), and most heat loss from the surface is by and transport.
Radiative energy losses become increasingly important higher in the atmosphere, largely because of the decreasing concentration of water vapor, an important greenhouse gas. It is more realistic to think of the greenhouse effect as applying to a 'surface' in the mid-, which is effectively coupled to the surface by a. The simple picture also assumes a steady state, but in the real world, there are variations due to the as well as the seasonal cycle and weather disturbances. Solar heating only applies during daytime. During the night, the atmosphere cools somewhat, but not greatly, because its emissivity is low. Decrease with height in the atmosphere. Within the region where radiative effects are important, the description given by the becomes realistic.
Air pollution, greenhouse gases and climate change: Global and. In balance.That,in anutshell,isthe theoryof thegreenhouse effect and global warming.
- The Greenhouse Effect: Global Warming 3 Procedures 1. Your teacher will have a demonstration of the greenhouse effect set up in the front of the.
- What the Greenhouse Effect is and how it works. Lesson Plan The Greenhouse Effect. Global Warming is the recorded increase in the average temperatures of the.
Earth's surface, warmed to a temperature around 255 K, radiates long-wavelength, heat in the range of 4–100 μm. At these wavelengths, greenhouse gases that were largely transparent to incoming solar radiation are more absorbent. Each layer of atmosphere with greenhouses gases absorbs some of the heat being radiated upwards from lower layers. It reradiates in all directions, both upwards and downwards; in equilibrium (by definition) the same amount as it has absorbed. This results in more warmth below. Increasing the concentration of the gases increases the amount of absorption and reradiation, and thereby further warms the layers and ultimately the surface below.
Greenhouse gases—including most diatomic gases with two different atoms (such as carbon monoxide, CO) and all gases with three or more atoms—are able to absorb and emit infrared radiation. Though more than 99% of the dry atmosphere is IR transparent (because the main constituents—N 2, O 2, and Ar—are not able to directly absorb or emit infrared radiation), intermolecular collisions cause the energy absorbed and emitted by the greenhouse gases to be shared with the other, non-IR-active, gases. Greenhouse gases. Atmospheric gases only absorb some wavelengths of energy but are transparent to others.
The absorption patterns of water vapor (blue peaks) and carbon dioxide (pink peaks) overlap in some wavelengths. Carbon dioxide is not as strong a greenhouse gas as water vapor, but it absorbs energy in longer wavelengths (12–15 micrometers) that water vapor does not, partially closing the 'window' through which heat radiated by the surface would normally escape to space.
(Illustration NASA, Robert Rohde)., 36–70%., 9–26%., 4–9%., 3–7% It is not possible to assign a specific percentage to each gas because the absorption and emission bands of the gases overlap (hence the ranges given above). Also absorb and emit infrared radiation and thus affect the radiative properties of the atmosphere. Role in climate change.
The of atmospheric CO 2 concentrations measured. Strengthening of the greenhouse effect through human activities is known as the enhanced (or ) greenhouse effect. This increase in from human activity is attributable mainly to increased atmospheric carbon dioxide levels. According to the latest Assessment Report from the, ' atmospheric concentrations of carbon dioxide, methane and nitrous oxide are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century'. CO 2 is produced by fossil fuel burning and other activities such as production and.
Effects Of Global Warming Pdf
Measurements of CO 2 from the Mauna Loa observatory show that concentrations have increased from about 313 parts per million (ppm) in 1960 to about 389 ppm in 2010. It reached the 400 ppm milestone on May 9, 2013. The current observed amount of CO 2 exceeds the geological record maxima (300 ppm) from ice core data. The effect of combustion-produced carbon dioxide on the global climate, a special case of the greenhouse effect first described in 1896 by, has also been called the.
Over the past 800,000 years, shows that carbon dioxide has varied from values as low as 180 ppm to the pre-industrial level of 270 ppm. Consider variations in carbon dioxide concentration to be a fundamental factor influencing climate variations over this time scale. Real greenhouses. A modern in The 'greenhouse effect' of the atmosphere is named by analogy to which become warmer in sunlight.
Global Warming
However, a greenhouse is not primarily warmed by the 'greenhouse effect'. 'Greenhouse effect' is actually a misnomer since heating in the usual greenhouse is due to the reduction of, while the 'greenhouse effect' works by preventing absorbed heat from leaving the structure through. A greenhouse is built of any material that passes sunlight usually glass, or plastic. The sun warms the ground and contents inside just like the outside, which then warms the air. Outside, the warm air near the surface rises and mixes with cooler air aloft, keeping the temperature lower than inside, where the air continues to heat up because it is confined within the greenhouse. This can be demonstrated by opening a small window near the roof of a greenhouse: the temperature will drop considerably.
It was demonstrated experimentally (, 1909) that a (not heated) 'greenhouse' with a cover of (which is transparent to infrared) heats up an enclosure similarly to one with a glass cover. Thus greenhouses work primarily by preventing cooling. Heated greenhouses are yet another matter, having an internal source of heating they leak heat out, which must be prevented. So it again makes sense to try to prevent radiative cooling through the use of adequate glazing. Related effects Anti-greenhouse effect.
Pictures Of Greenhouse Effect And Global Warming
See also: A occurs if lead to the evaporation of all greenhouse gases into the atmosphere. A runaway greenhouse effect involving carbon dioxide and water vapor has long ago been hypothesized to have occurred on Venus, this idea is still largely accepted. Bodies other than Earth The greenhouse effect on Venus is particularly large because its dense atmosphere consists mainly of carbon dioxide. 'Venus experienced a runaway greenhouse in the past, and we expect that Earth will in about 2 billion years as solar luminosity increases'. Titan has an anti-greenhouse effect, in that its atmosphere absorbs solar radiation but is relatively transparent to outgoing infrared radiation. Is also colder than would be expected because evaporation of nitrogen cools it.