A change in temperature is a change in climate. We worry about man-made climate change if a temperature change will last decades or centuries and if the change will disfigure the environment.
The physical basics of climate change state that “atmospheric carbon dioxide dioxide concentrations are rising, carbon dioxide dioxide is a greenhouse gas, and it absorbs and re-radiates longwave radiation downwards. The radiation is trapped (or at least delayed) meaning that there is more of it around and hence temperatures go up.” 
Solar energy which would normally go out into space is kept inside earth’s weather system by the presence of carbon dioxide.
Carbon dioxide and other greenhouse gases, especially water, “trap some of the heat we receive from the sun and prevent it from bouncing back into space.” 
How much can increased atmospheric carbon dioxide be expected to warm the earth? If the…