Answer:
"Carbon dioxide (CO2) is one of a number of gases that are transparent to the visible light falling on the Earth from the Sun, but absorb the infra-red radiation (heat) emitted by the warm surface of the Earth, preventing its loss into space. During the geological history of the Earth the level of atmospheric CO2 has varied considerably and this has had an impact on the global temperature. A significant amount of this atmospheric carbon was sequestered or (removed from the atmosphere) and turned into inert material (coal, and oil) typically 300-360 Million years ago. All of the global ecosystems and species have adapted to a lower level of atmospheric CO2 and critically, human civilisation has also grown since that period.  Since the industrial revolution humans have been burning sequestered CO2 in the form of coal, oil, and natural gas which has the result of releasing energy but also releases CO2 back into the atmosphere".
 
        
             
        
        
        
Hey there! 
Answer: Protons 
The atom in a sample of an element must contain nuclei with the same number of protons. If the protons change in number, then the element will modify as well. 
Thank you!
        
             
        
        
        
1) you want to increase friction when it gets cold. If you're outside and it's really cold, you're going to rub your hands to warm them up, therefore friction is increasing 
I'm not do sure about decreasing.