-- Shares Facebook Twitter Reddit Email 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.

"As a scientist, I’m always cautious of the word 'prove,' but our work demonstrates the important role that atmospheric carbon dioxide (CO2) concentrations play in controlling Earth’s temperature," Emily Joan Judd, the lead study author and paleontologist at the Smithsonian National Museum of Natural History, said to Salon. Related Climate change is making crabs lose their sense of smell — and seafood may never be the same "We know that today – and in the recent past – CO2 and temperature are directly linked; however, over really long-time scales – like hundreds of millions of years – other influences, such as the fact that the sun is getting progressively brighter, also play a role in modulating climate,” Judd continued. While climate change deniers seize on external variables like these to cast doubt on humanity’s culpability.