A nuclear war between two countries would be enough to plunge the world into a “Little Ice Age”, scientists have warned.

Researchers found that even nations not involved in the dispute would suffer crop failures and plummeting temperatures, as the soot and smoke from nuclear firestorms thousands of miles away would block out the sun.

In the first month following nuclear detonation, average global temperatures would plunge by about 13F – a larger temperature change than in the last Ice Age, warned experts from Louisiana State and Rutgers universities.

As the planet became colder, sea ice would expand by more than six million square miles and 6ft deep in some basins, blocking major ports including Beijing’s Port of Tianjin, Copenhagen and St Petersburg.

Read more: yahoo