Giant tsunamis, super volcanoes and earthquakes could pose a greater threat than terrorism, scientists claim.
We are making good progress in reducing the threat of asteroid impacts
Global Geophysical Events, or "Gee Gees", as they are nick-named, are not being taken seriously enough, they say.
The global community needs to monitor these risks, and develop strategies to cope in the face of a catastrophe.
However, we are making good progress in reducing the threat of asteroid impacts, the researchers said during a briefing at the Royal Institution, UK.
Since 9/11 we have become acutely aware of the threat of terrorism. Governments worldwide are battening down the hatches and ratcheting up the security.
But, in terms of grave threats, are we really looking in the right direction?
Giant walls of water that can devastate coastal cities, volcanoes so big that their ash crushes houses 1,500km (932 miles) away, giant earthquakes and asteroid impacts. These are very rare events and, if we are lucky, nothing like them will happen in our lifetimes.
But in the longer term, Gee Gees may be our undoing if we do not take action. According to researchers, careful preparation could potentially save thousands of lives.
"In any one year the chances of one of these things happening is probably much less than 1%," said Bill McGuire, director of the Benfield Grieg Hazard Research Centre. "But in the longer term it is 100%.
"We need to raise awareness, identify threats and improve surveillance.
"We need to plan what we will do if these things happen."
Volcanoes and earthquakes are relatively common occurrences, but Gee Gees are on an altogether different scale.
The last "super volcanic eruption" was back in April 1815, when Tambora in Indonesia exploded violently, in what was the largest eruption in historic time.
The eruption column reached a height of about 44 km (28 miles), ash fell as far as 1,300 km (800 miles) from the volcano - and an estimated 92,000 people were killed.
Rare though they are, events this catastrophic need to be taken very seriously.
The potential threat that scientists currently have their eye on is an insecure rock - the size of the Isle of Man - in the Canary Island of La Palma.
The rock is in the process of slipping into the sea and Professor McGuire fears that when it finally collapses, the resulting tsunami will cause massive destruction along the coasts of countries like the USA, UK and many on the African continent, within a matter of hours.
"Eventually the whole rock will collapse into the water, and the collapse - when it happens - will devastate the Atlantic margin," said Professor McGuire.
The global community needs to monitor the risk posed by Gee Gee's, scientists claim
The triggering factor could be the eruption of the volcano on La Palma, called Cumbre Vieja, which could feasibly blow "anytime", according to Professor McGuire.
Many researchers working in the field of Gee Gees would like better monitoring of Cumbre Vieja, so that advance warning can be given for the possible collapse of the rock.
"We need to be out there now looking at when an eruption is likely to happen," said Professor McGuire. "Otherwise there will be no time to evacuate major cities."
Global governments are not entirely ignoring the threat of Gee Gees, however.
The greatest danger to humanity comes from asteroids, but work funded largely by the US government is swiftly tackling this threat.
Work funded by the US government is swiftly tackling the threat posed by asteroids
The European Space Agency (Esa) and Nasa are planning missions to test how the course of asteroids and comets can be altered by an impact.
Esa's mission Don Quijote will send a spacecraft crashing into the surface of a space rock to measure the effects. In 2005, Nasa's Deep Impact will monitor the outcome of blowing a hole in comet Tempel 1.
Scientists hope this will help them learn how to destroy or deflect an asteroid on a collision course with Earth.
According to Benny Peiser, of Liverpool John Moores University, UK, the threat of cosmic mega disasters will be essentially "abolished within 30 years".
"A quiet and largely unnoticed technological revolution is dramatically accelerating the rate at which near-Earth asteroids (NEAs) are discovered," he said.
In 1995 we knew about 300 NEAs, today we know about 3000 - and within 20 years we could be aware of 90% of all nearby space rocks, he says.
"For the first time in the history of evolution we are closing this window of vulnerability."