Firor Said the World Might Eventually Have to Cut Its

Essay

Firor said the world might eventually have to cut its carbon dioxide production by half in order to stabilize the gas in the atmosphere but that this might not happen until the world had already warmed an average of 4 or 5 degrees Fahrenheit, an increase that still could have significant and perhaps catastrophic effects. In fact, scientists say it might even be necessary to reduce emissions by as much as 90 percent to reverse warming and to restore the climate to that of pre-industrial times before man-made carbon dioxide began accumulating in the atmosphere.
-William Booth
-What causes and effects does Booth cite? How do they relate to the topic sentence?