9/11 anniversary: US marks 10 years since attacks
The US has started to mark the 10th anniversary of the 9/11 attacks on New York, Washington and Pennsylvania.
The BBC 11 September 2011
Security is tight following warnings of a possible al-Qaeda attack.
The US embassy in Afghanistan has begun the ceremonies, with events due later in the sites where four hijacked planes struck, killing nearly 3,000 people.
An official memorial to those who died is to be unveiled at the site of the World Trade Center, whose twin towers were destroyed in the attacks.
Metal barriers have been erected on roads near the World Trade Center, while police in New York and Washington are stopping and searching large vehicles entering bridges and tunnels.
Coral reefs 'will be gone by end of the century'
They will be the first entire ecosystem to be destroyed by human activity, says top UN scientist
By Andrew Marszal Sunday, 11 September 2011
Coral reefs are on course to become the first ecosystem that human activity will eliminate entirely from the Earth, a leading United Nations scientist claims. He says this event will occur before the end of the present century, which means that there are children already born who will live to see a world without coral.
The claim is made in a book published tomorrow, which says coral reef ecosystems are very likely to disappear this century in what would be "a new first for mankind – the 'extinction' of an entire ecosystem". Its author, Professor Peter Sale, studied the Great Barrier Reef for 20 years at the University of Sydney. He currently leads a team at the United Nations University Institute for Water, Environment and Health.