[00:00.84]D Volcanoes and earthquakes
[00:03.57]are even more dangerous than in the past
[00:06.34]as around half the world's population now
[00:08.95]lives in cities.
[00:10.41]There are more than 500 active
[00:12.79]and semi-active volcanoes,
[00:14.61]about fifty of which erupt each year,
[00:16.96]and more than 500 million people
[00:19.24]now live within the range
[00:21.16]of a volcanic eruption.
[00:23.54]An even greater number live at risk,
[00:25.98]in some degree, from earthquakes
[00:28.05]which have taken a toll
[00:29.36]of more than 1.6 million
[00:31.45]lives in the last hundred years.
[00:35.82]E All the betting
[00:37.68]from the disaster professionals
[00:39.11]in that things will get worse.
[00:41.53]Professor Hou Ming, of Beijing University,
[00:43.99]is a volcanologist who has been warning
[00:46.34]for years that the world has not seen the worst
[00:48.83]nature can do.
[00:50.43]The worst eruption in human history
[00:52.31]was probably Mt Tambora in 1815,in Indonesia.
[00:57.86]It pumped so much dust into the air
[01:00.18]that it effectively cancelled the following
[01:02.09]summer in Europe and America.
[01:04.50]But geographial evidence shows
[01:06.33]that 73,000 years ago
[01:08.31]there was a much greater eruption.
[01:10.64]"It reduced temperatures by maybe 6C
[01:14.89]in some places and the whole planet
[01:17.28]was plunged into winter for years.
[01:19.83]And there are about two of these events
[01:22.09]every 100,000 years..."
[01:23.55]