Scientists say that doubling pre-industrial carbon dioxide levels will likely cause global average surface temperature to rise between 1.5Â° and 4.5Â° Celsius (2.7Â° to 8.1Â° Fahrenheit) compared to pre-industrial temperatures.
Furthermore, they may experience withdrawal symptoms that can include headaches and irritability, perceived loss of performance both physically and mentally. People suffering with intolerance to caffeine have reported feelings of disorientation, loss of judgment, anxiety, dizziness, agitation and a hyper activeness.
As with most food intolerances, and reaction to caffeine is classed as an intolerance not an allergy, the answer to this question depends very much on the individual. People are affected by caffeine in different ways; some are much more sensitive than others and have to adjust their intake accordingly.