How the temperature is changed on earth and is related to snowfall?


 For People who live in snow country, temperature would be very important, especially for people who live in the place where specialized in snow sports.

If there's no snow, snow sports, hotel and ski resort business damage economically. and the hiring rate would be also decreased. Although many reasons are related to snowfall, temperature is one of the most important aspect of the amount of snowfall.  What factors affects the temperature?

The mechanism of the temperature

The Earth's temperature is mostly determined by the balance between the radiant energy from the sun (the energy received by the earth) and the radiant energy from the earth. (1) The Earth receives energy from the sun and emits infrared light into the universe with almost the same amount of energy.

When the earth emits infrared light into the universe with almost the same amount of energy,  the average temperature near the surface of the earth will be approximately -19 ° C based on calculation following basic physics rule. (2)  

So what makes the earth warmer?  Greenhouse effect has important role to keep temperature good for organism. Some of the infrared radiation emitted from the earth's surface is absorbed by the atmosphere.

And infrared light is emitted from the atmosphere to the earth's surface. Due to this effect, the average temperature near the actual ground surface is about 14 ° C. (2

Created by Snow notes according to 地球の環境

The more CO2 increased, The more greenhouse effect increased.

So what’s happening when greenhouse effects happen?  This is simplified animation from UCAR. In terms of the molecule level, the energy causes the vibration of the molecule and the molecule gives up to get extra energy  by emitting infrared radiation in a different angle. (3) When the molecule finished emitting infrared radiation, it stops vibration.(3

Photos by UCAR

The more CO2 molecules, the more absorption and emission are repeated. As the number of times of absorption and emission by CO2 molecules increases, infrared rays are emitted not only upward but also downward. And What’s happen?  It means that more infrared rays reach back to the surface of the earth.(2)

Created by Snow notes according to CGER

What is infrared radiation by the way?  

According to Live science, Infrared radiation  (IR) is a type of radiant energy.  It’s invisible to human eyes but able to feel as a heat. Mostly main sources of IR is sun and fire. As IR transmit heats, Household appliance such as toasters and industrial heaters use IR radiations. 
Radiation means transfer of energy through space from a source and IR is a part of the radiation (4)  There are also different type of radiations such as  electromagnetic, thermal, acoustic, particle radiation (such as alpha or beta radiation from a radioactive source), and ionizing radiation. The picture below is the graphs of electromagnetic spectrum. 

Created by Snow notes according to Radiation and Nuclear Health Hazards

How the temperature related to snowfall?

There’s goldilocks temperatures for snowing. The heaviest snowfalls occur between 28°F – 32°F (-2.2°C – 0°C). So it's expected that the heavy snow area will be changed north to north. Of course moisture is also needed to get snow. (Japan gets a lot of snow because of moistures from Japan sea). In the future, Japan might not get snow if all area becomes more than 0°C.

Does Global warming leads to more snow or less snow?