The best case scenario for climate change just got worse

A climate change study published Wednesday shows it is "extremely unlikely" that Earth's climate sensitivity could be "low enough to avoid substantial climate change" with continued high emissions.

Climate sensitivity is the measure of how susceptible Earth's climate is to human influence, per the study. In a 1979 report on sensitivity, it was estimated that if the carbon dioxide levels in Earth's atmosphere were to double compared to pre-industrial levels, temperatures could increase between 2.7 to 8.1 degrees Fahrenheit.

Now, scientists have narrowed the range to 4.1 to 8.1 degrees Fahrenheit.

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If the rate of emissions continues, doubled carbon dioxide levels will be reached in roughly 50 years, according to the National Oceanic and Atmospheric Association. There is a 95 percent chance that when that happens, it will lead to a warming of more than 3.6 degrees — "the threshold beyond which scientists say the Earth will suffer dangerous effects — disruptive sea level rise, intolerable heat waves, and other extreme weather and permanent damage to ecosystems," reports The Washington Post.

The doubling of carbon dioxide levels can be prevented only if humans enact swift measures. "The primary determinant of future climate is human actions," Kate Marvel, a physicist at NASA's Goddard Institute of Space Studies and Columbia University, told the Post.

But if human activities do push carbon dioxide levels to double, the study shows it would be less likely that the Earth remains below a 3.6 degree increase, and more likely that it exceeds the upper limit of the new range. If the temperatures reach even the middle of the new range, it would be a "five-alarm fire" for the planet, Marvel told the Post.

The study was published in Reviews of Geophysics, and is sponsored by the World Climate Research Program. It was conducted by 25 researchers across the world. Read more at The Washington Post.