archived (Wayback Machine):
every additional degree Celsius of global warming on average will drag down the world's ability to produce food by 120 calories per person per day
"If the climate warms by 3 degrees, that's basically like everyone on Earth giving up breakfast."
When an adult male is unable to obtain at least 2100 kcal per day, the WHO considers that a famine. Either the above excerpts assume that breakfast accounts for only a small portion of daily calories, or (if breakfast accounts for even close to 1/3 of daily calories), the human population is, on the average, in a state of severe famine all of the time. Or both.