The Black Plague–the disease that wiped out most of Europe’s population in the fourteenth century–was spread by rats. Right? While rodents did play a role in the spread of this illness, the roots of the pandemic can be traced back to climate change.

Did Climate Change Cause the Black Plague?


In the fourteenth century, the Black Death wiped out two-thirds of Europe’s population. Centuries later, scientists are trying to figure out why.

One theory suggests that the plague was triggered by climate change.

Scientists believe the plague bacteria is originated in central Asia.

This type of bacteria is sometimes found in fleas from that area.

These fleas live on rodents like the wild gerbil. The plague bacteria is a part of an ecosystem.

And weather affects ecosystems. According to research, the plague’s worst outbreaks have occurred during periods of very dry, followed by very wet weather.

When climate swings from a drought to intense rain, fleas multiply. The rain also affects rodents, who may have to migrate from their flooded burrows. The infected fleas hitchhike from rodent to rodent, and then from a rodent to a person.

These rodents end up on ships and trading routes, spreading the bacteria.

One study linked the dry-to-wet change in Northern Pakistan to outbreaks of plague in Europe. 

Although the plague can be caused by climate change, that doesn’t mean it will happen anytime soon.

Today, there are several antibiotics that can successfully treat the plague. Outbreaks occur occasionally, but are controlled with medicine.

By understanding the secrets of the plague, scientists can continue to stop it in its tracks.


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This video uses an image of a mosquito instead of a flea due to limited design capabilities of the creation platform. A cat is used in the place of a gerbil for similar reasons.