Four Corners: Global Dimming
Questions to answer from video Four Corners: Global Dimming
• How does the film start? The film starts by talking about the green house effect and the natural disasters and also the terrorist attacks aftermath.
• Who was Gerald Stanhill? – What was his occupation? – Why was he measuring solar radiation in the 1950s? – In which country did he take his measurements? – What did he find 20 years later? – Did anyone believe him? He is a English immigrant, a trained biologist. -Gerry got a job helping to design irrigation schemes. His task was to measure how strongly the sun shone over Israel. -Because there was a staggering 22% drop in the sunlight, and that really amazed him. A 22% drop in solar energy was simply massive. If it was true surely Israelis should be …show more content…
In the polluted air billions of man-made particles provided ten times as many sites around which water droplets could form. So polluted clouds contained many more water droplets, each one far smaller than it would be naturally. Many small droplets reflect more light than fewer big ones. So the polluted clouds were reflecting more light back into space, preventing the heat of the sun getting through. This was the cause of Global Dimming.
• Why is global dimming thought to be linked to drought in the Sahel?
The Sahel's lifeblood has always been a seasonal monsoon. For most of the year it is completely dry. But every summer, the heat of the sun warms the oceans north of the equator. This draws the rain belt that forms over the equator northwards, bringing rain to the Sahel.
Polluted clouds stopped the heat of the sun getting through. That heat was needed to draw the tropical rains northwards. So the life giving rain belt never made it to the Sahel.
Global dimming could have been behind this drought.
• What is the most convincing evidence of the effect of particles on reducing
• How does the film start? The film starts by talking about the green house effect and the natural disasters and also the terrorist attacks aftermath.
• Who was Gerald Stanhill? – What was his occupation? – Why was he measuring solar radiation in the 1950s? – In which country did he take his measurements? – What did he find 20 years later? – Did anyone believe him? He is a English immigrant, a trained biologist. -Gerry got a job helping to design irrigation schemes. His task was to measure how strongly the sun shone over Israel. -Because there was a staggering 22% drop in the sunlight, and that really amazed him. A 22% drop in solar energy was simply massive. If it was true surely Israelis should be …show more content…
In the polluted air billions of man-made particles provided ten times as many sites around which water droplets could form. So polluted clouds contained many more water droplets, each one far smaller than it would be naturally. Many small droplets reflect more light than fewer big ones. So the polluted clouds were reflecting more light back into space, preventing the heat of the sun getting through. This was the cause of Global Dimming.
• Why is global dimming thought to be linked to drought in the Sahel?
The Sahel's lifeblood has always been a seasonal monsoon. For most of the year it is completely dry. But every summer, the heat of the sun warms the oceans north of the equator. This draws the rain belt that forms over the equator northwards, bringing rain to the Sahel.
Polluted clouds stopped the heat of the sun getting through. That heat was needed to draw the tropical rains northwards. So the life giving rain belt never made it to the Sahel.
Global dimming could have been behind this drought.
• What is the most convincing evidence of the effect of particles on reducing