Solar+Radiation+Management

= Geoengeneering =

Solar radiation management
=== Hello, and welcome to João Pinheiro´s Wiki page about solar radiation management, check out my partner´s page here and also here on Geoengeneering. ===

Solar radiation management projects are a type of geoengineering which aim to reduce the amount of harmful sun radiation hitting the Earth as a way to respond to global warming. We also need to refer to global dimming as a side-effect of fossil fuel use is known a lot, and it is not necessarily a geoengineering technique, as it occurs in normal conditions, due to aerosols caused by pollution, or caused naturally as a result of volcanoes and forest fires. However, its manipulation is a tool of geoengineering, and its main purpose also.
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Solar radiation management projects do not reduce greenhouse gas concentrations in the atmosphere, and so they do not address problems such as ocean acidification caused by these gases. Their principle advantage in relation to geoengineering is the speed with which they can be organized and become fully active.

Solar radiation management project can be divided up to 3 categories, the atmospheric projects, which seek to modify the atmosphere, either by enhancing natural processes or by using artificial techniques made by man, also terrestrial albedo modification projects which aims to enhance the reflectivity of the earth's surface reducing the amount of heat retained, and space projects, which are possible types of a different solution, but normally are seen as too radical and expensive to implement them.

Here is a list of possible projects in each category with a brief description of each from: []


 * Solar radiation management projects **
 * Atmospheric projects: **
 * **Stratospheric sulfur aerosols** -modify the Earth's albedo with reflective or absorptive materials spread over portions of its surface.
 * **Reflective aerosols or dust methods** - use tiny metal flakes or silica compounds added to the fuel of jet airliners, so that particles would be emitted from the jet engine exhaust.
 * **Cloud whitening / marine cloud brightening / cloud reflectivity enhancement projects** -recommend that ships spray seawater into the air to create clouds, shielding the earth from the sun.
 * **Cloud seeding-** is the use of airliners to distribute the cloud-seeding materials or the burning of sulfur in ships or power plants to form sulfate aerosol in order to stimulate additional low marine clouds to reflect sunlight.
 * **Ocean sulfur cycle enhancement** -would enhance the natural sulfur cycle in the southern ocean by fertilizing a small portion with iron in order to enhance dimethyl sulfide production and cloud reflectivity. The goal would be to slow Antarctic ice from melting and raising sea level.
 * **Reflective balloons** -suggests billions of aluminized, hydrogen-filled balloons be placed in the stratosphere to provide a reflective screen.
 * **Low stratospheric soot (Dust)** - could be created by decreasing the efficiency of burning in engines of aircraft flying in the low stratosphere to maintain a thin cloud of soot to intercept sunlight.


 * Terrestrial albedo modification projects: **
 * ** Cool roof -** Painting pavements and roof materials in white or pale colours to reflect solar radiation, known as 'cool roof' technology, is encouraged by legislation in some areas. This is a benign technique, and it can reduce the need for air conditioning.
 * ** Reflective plastic sheeting - **covers 67,000 square miles of desert, to reflect the Sun’s energy could offset the current level of warming. However, the effect would be strongly regional.
 * ** Ocean litter -** An early idea was to use pale coloured floating litter within stable oceanic gyres.
 * ** Farming, forestry, and land management -** Reforestation in tropical areas has a cooling effect. Deforestation of high-latitude and high-altitude forests exposes snow that increases albedo. Changes to grassland could increase albedo, and selecting or genetically modifying commercial crops with high albedo has been suggested.


 * Space projects: **
 * ** Mirrors in space - **could deflect a percentage of solar sunlight into space.
 * ** Mining moon dust- **could create a shielding cloud.
 * ** Dispersive solutions -** Proposes to disperse light before it reaches the Earth by putting a very large diffraction grating or lens in space. Side-effects include that, if this lens were built and global warming were avoided, there would be less incentive to reduce greenhouse gases, and humans might continue to produce too much carbon dioxide until it caused some other environmental catastrophe, such as a chemical change in ocean water that could be disastrous to ocean life.


 * Key Terms List: **
 * Albedo-** It is the percentage of sunlight reflected by planet earth out of space;
 * Global dimming- ** It ** ´ **s the gradual reduction in the amount of irradiance at the Earth's surface that was observed for several decades after the start of systematic measurements in the 1950s. The effect varies by location, but worldwide it was estimated to be a 4% reduction from 1960–1990. Since then, a very slight reversal in the overall trend has been observed;
 * Geoengeneering-** It´s the large-scale engineering and manipulation of the planetary environment, often to combat or counteract anthropogenic changes in atmospheric chemistry such as sea water acidification from the greehousegas effect;
 * Atmospheric aerosols-** Are solid and liquid particles suspended in the earth´s atmosphere joined with certain chemicals in order to reflect the harmeful solar radiation from the earth´s surface;
 * Photochemical-** Is the name given to chemical reactions that proceed with the absorption of light by atoms or molecules,such as pjotosynthesis from plants, which can be used for geoengeneering projects;
 * Greenhouse Effect-** It´s the phenomenon whereby the earth's atmosphere traps solar radiation, caused by the presence in the atmosphere of gases such as carbon dioxide, water vapor, and methane that allow incoming sunlight to pass through but absorb heat radiated back from the earth's surface.

[] This link refers to the current event of the encouragement for people to adopt Climate Sensitivity and Effectiveness of Solar Radiation Management by Dr. Katharine L. Ricke, as a solution for solar radiation and greenhouse effect.
 * Current Event: **

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