Though not in the public's consciousness as much since the Cold War came to a close around 1989 and the break up of the Soviet Union in 1991, the possibility of nuclear war exists as long as the weapons themselves do. But researchers focusing on climate have theorized the dire effects of such a war upon the climate may be just as bad or worse. This iridium did not have an easy terrestrial explanation. This theory suggests that a large meteorite hit the Earth around 65 million years ago, causing fires. This meteor would explain the iridium deposits and the fires would explain a surplus of carbon that has also been discovered at the K-T boundary layer.
Scientists know that iridium is much more common in asteroids and meteors than it is on Earth.
Other researchers studying carbon deposits in sedimentary layers have documented a period in Earth s past when ancient wildfires were widespread. Fossils in the sediments in the K-T boundary also show a strange disappearance of about 50 percent of the genera in this period of time. These ancient fires may provide evidence from Earth's past that give us an idea of how a nuclear war climate might affect the climate. It would be hard to prepare for the striking of an asteroid, though in Hollywood films mankind always gets together to defeat even such a random event. But we can all hope that nuclear war, depending as it does on the hatreds and fears of mankind, will never be quite so random.