But not only the impact of a massive asteroid has a devastating effect on the planet, also volcanic eruptions can cause massive destructive impact on the planet or sudden climate changes.
The year 1816 is known as the Year Without a Summer, because of severe summer climate abnormalities that caused average global temperatures to decrease by 0.4–0.7 °C (0.7–1.3 °F). This resulted in major food shortages across the Northern Hemisphere. Evidence suggests that the anomaly was caused by a combination of a historic low in solar activity with a volcanic winter event, the latter caused by a succession of major volcanic eruptions capped by the 1815 eruption of Mount Tambora, in Indonesia, the largest known eruption in over 1,300 years. The Little Ice Age, then in its concluding decades, may also have been a factor.
In 1883, the Krakatoa Volcano Eruption in Indonesie was a major disaster and a worldwide weather event. The volcanic dust thrown into the atmosphere affected the weather around the world, and people as far away as Britain and the United States saw bizarre red sunsets caused by particles in the atmosphere.
Following the eruption of the volcano, the area near Krakatoa was enveloped in a strange darkness, as dust and particles blasted into the atmosphere blocked sunlight. And as winds in the upper atmosphere carried the dust great distances, people on the other side of the world began to notice the effect.
According to a report in the Atlantic Monthly magazine published in 1884, some sea captains had reported seeing sunrises that were green, with the sun remaining green throughout the day. The vividness of the sunsets continued for nearly three years.
More recently, the 1908 Tunguska event is the largest impact event on or near Earth in recorded history. It is classified as an impact even though the asteroid or comet is believed to have burst in the air rather than hitting the surface. It is said a UFO collided with the Tunguska Meteorite to save the earth.
The latest massive asteroid event happened last year. The Chelyabinsk meteor was a near-Earth asteroid that entered Earth's atmosphere over Russia on 15 February 2013 at almost 60 times the speed of sound. The light from the meteor was brighter than the Sun, even at 100 km distance.
Despite NASA downplays risks of a massive asteroid impact, given the history, the risk that another large asteroid will hit the earth or a new devastating volcanic eruption will occur, is very likely and is just a matter of time.
This is dummy text. It is not meant to be read. Accordingly, it is difficult to figure out when to end it. But then, this is dummy text. It is not meant to be read. Period.