17S6F greenhouse by Dave Lommen https://padlet.com/dave52/group10 Greenhouse effect en-us 2018-01-07 09:49:32 UTC 2018-01-08 06:11:59 UTC hello@padlet.com https://padlet.com/dave52/group10/wish/219234071 Greenhouse gases such as water vapour, methane and carbon dioxide stop heat escaping from the Earth into space. An increased greenhouse effect can lead to global warming and climate change.

The greenhouse effect

Some gases in the Earth’s atmosphere stop heat radiating into space from the Earth. This is called the greenhouse effect and the gases involved are called greenhouse gases. They include:

  • methane
  • water vapour
  • carbon dioxide.
The diagram shows how the greenhouse effect works.

Greenhouse effect

  1. Electromagnetic radiation at most wavelengths from the Sun passes through the Earth’s atmosphere.
  2. The Earth absorbs electromagnetic radiation with short wavelengths and so warms up. Heat is radiated from the Earth as longer wavelength infrared radiation.
  3. Some of this infrared radiation is absorbed by greenhouse gases in the atmosphere.
  4. The atmosphere warms up.
]]> 2018-01-08 06:03:20 UTC https://padlet.com/dave52/group10/wish/219234071 Greenhouse effect https://padlet.com/dave52/group10/wish/219234145 https://youtu.be/ZzCA60WnoMk]]> 2018-01-08 06:04:12 UTC https://padlet.com/dave52/group10/wish/219234145 Definition (Collins Dictionary) https://padlet.com/dave52/group10/wish/219234199 The greenhouse effect is the problem caused by increased quantities of gases such as carbon dioxide in the air. These gases trap the heat from the sun, and cause a gradual rise in the temperature of the Earth's atmosphere.]]> 2018-01-08 06:05:16 UTC https://padlet.com/dave52/group10/wish/219234199 https://padlet.com/dave52/group10/wish/219234286 Increased global warming will lead to climate change – changes in the average weather experienced over 30 years or more. Climate change may make it impossible to grow certain food crops in some regions. Melting polar ice, and the thermal expansion of sea water, could cause rising sea levels and the flooding of low-lying land.


Difficulties

There is a good agreement between scientists about how the greenhouse effect works. However, there is less agreement about the extent to which human activities are causing an increased greenhouse effect, and so global warming with its associated climate change. The balance of scientific opinion is that human activities are to blame.

It is not just the release of carbon dioxide and methane that can contribute to global warming. Dust produced from factories goes into the atmosphere that reflects radiation back to the Earth and causing warming too.

However, it is not just human activities that can affect weather patterns and climate. Ash and gases released by volcanic eruptions also go into the atmosphere. They reflect radiation from the Sun back into space, causing cooling. This, and other effects, can make it difficult for scientists who study the atmosphere and global warming.

]]> 2018-01-08 06:06:14 UTC https://padlet.com/dave52/group10/wish/219234286 https://padlet.com/dave52/group10/wish/219234390 Light shining on the Earth passes through the atmosphere relatively unimpeded, but it becomes trapped and can't leave as easily.

In greater detail, light flows in and heats the surface. The surface radiates some of the absorbed energy back. If there was no atmosphere, this radiation would escape into space; however, the earth does have an atmosphere which absorbed some of the earth radiated energy and re-radiates it. This gives the earth a second chance to absorb the energy.

]]> 2018-01-08 06:07:24 UTC https://padlet.com/dave52/group10/wish/219234390 Why is water trapped in the troposphere https://padlet.com/dave52/group10/wish/219234820 The Tropopause: At the very top of the troposphere is the tropopause where the temperature reaches a (stable) minimum. Some scientists call the tropopause a "thermal layer" or "cold trap" because this is a point where rising water vapour cannot go higher because it changes into ice and is trapped. ]]> 2018-01-08 06:11:42 UTC https://padlet.com/dave52/group10/wish/219234820