Climate change deniers inaccurately claim that Earth's rapidly rising temperatures are the mere product of natural cycles. Scientific experts have long explained that, although Earth does experience natural cycles, they do not explain how the average carbon dioxide level in the atmosphere is 419 parts per million, as opposed to the preindustrial level of 280 parts per million.
Now a study in the journal “Science” provides illuminating new context about the history of Earth's temperatures — and illustrates precisely how the current spike is the result of humanity's overuse of fossil fuels.
