What is "Geoengineering" that sails sulfur dioxide in the stratosphere to block sunlight and prevent global warming?

As the increase of greenhouse gases such as carbon dioxide has caused the earth's temperature to rise sharply more than ever since the 20th century. The idea of ​​blocking sunlight by spraying gas in the stratosphere against global warming that should also be called the crisis of the global environment, such as climate change accompanied by temperature rise due to climate change, etc. Come on Discussion is in confusion about.

Climate Hackers: One man's plan to stop global warming by shooting particles into the atmosphere | The Verge
http://www.theverge.com/2016/8/24/12589796/climate-hackers-david-keith-geoengineering-climate-change

Sprinkle sulfur dioxide in the stratosphereGeoengineeringThe Verge creates a movie about what it is like.

A scientist's plan to hack the climate - YouTube


We are at a major turning point in climate change.


It is exposed to the risk of massive famine and millions of food refugees.


While climate change is growing due to global warming, political discussions towards solutions have not yet reached agreement.


Meanwhile, the concept of "Geoengineering" is perfect for the word "hack climate".


Dr. David Keith of Harvard University is known as the breakthrough in Geoengineering. "We can reduce the temperature rise due to global warming by half at low cost" and explain the possibilities of Geoengineering.


Dr. Keith's thought of Geoengineering's basic idea is to reduce the heat generated by the sunlight falling on the earth.


With the increase of greenhouse gases, we will reduce the temperature of the earth, which rises more rapidly than ever, by cutting off heat from the sun.


Dr. Keith's idea is to skip the plane to the stratosphere ......


Spraying gas in the stratosphere.


It is sulfur dioxide that is sprayed.


The stratospheric sulfur dioxide combines with oxygen atoms and water ... ...


It becomes sulfuric acid molecule.


It is an idea that sulfuric acid molecules drifting in the stratosphere try to reflect the sunlight and reduce the heat that is poured on the earth.


Dr. Keith estimates that the cost of dispersing sulfur dioxide in the stratosphere is $ 2 billion per year (about 200 billion yen)


To the contrary, Dr. Keith thinks Geoengineering is extremely cost-effective, as the cost of being obliged to contribute by climate change is 1.9 trillion dollars a year (about 190 trillion yen).


Of course, there are voices of concern about the negative influence on the global environment by Geoengineering using sulfur dioxide which Dr. Keith and others have argued.


Volcanic eruption is an optimal natural phenomenon as a model of Geoengineering using sulfur dioxide. In the Philippines in 1991Pinatubo MountainThe greatest eruption in the 20th century that occurred in the world greatly changed the climate around the world.


It is estimated that this natural phenomenon lowered the temperature of the earth by 0.5 degrees.


However, Geoengineering utilizing sulfur dioxide has concerns about the ozone layer as well as the eruption of Mount Pinatubo.


Some researchers think that Geoengineering utilizing sulfur dioxide can have a bad influence on tropical rainforests.


Washington Climate Wil Burns of the Geoengineering Consortium says that Geoengineering utilizing sulfur dioxide is concerned with the potential danger of having a huge harmful effect on the global environment.


Mr. Burns points out the possibility of affecting the climate of the tropical monsoon region and regions such as Africa.


To Geoengineering not only ideas to spray sulfur dioxide but also enclose carbon dioxide in the ground or in the seaCCSThere are various kinds, and discussions are already being held at a global conference, but opinions on effectiveness and danger do not agree.


Regarding the degree of influence on the ozone layer, reports that sulfur dioxide-based Geoengineering has a bigger adverse effect than alumina and diamond dust has also been reported.


Meanwhile, there are also verification results that diamond dust has a higher effect of suppressing the global temperature rise than sulfur dioxide.


On the other hand, there is also a view that Geoengineering can make more crops.


Dr. Keith thinks Geoengineering is far superior to the effect of stopping the rise in temperature due to the reduction of greenhouse gases such as carbon dioxide.


If greenhouse gases are discharged as usual without any countermeasures against global warming, the temperature of the earth is considered to be a "danger zone" in 2000 compared to 2000 in the year 2050 The rise of "twice" It is estimated to rise to near "6 degrees" in 2100.


It is for the first time that the increase in the temperature rise by 2100 can be suppressed to 2 degrees or less by performing strong measures such as Geoengineering utilizing sulfur dioxide.


Apart from whether or not to adopt Geoengineering with sulfur dioxide, global warming countermeasures are a situation without waiting, and the leaders of countries around the world are obliged to make a decision sooner or later.