Rio 20 zero draft accepts planetary boundaries

The latest draft of the so-called \'zero draft\' document, which will be presented to heads of government at the Rio+20 Summit in June, has been amended to include an acknowledgement that there are scientifically assessed \'planetary boundaries\' which, if overstepped, could result in irreversible damage to the Earth\'s sytems. The draft is being prepared by national delegates to the United Nations, and will ultimately be presented to heads of government at the Summit for their endorsement. The idea of planetary boundaries, referring to the load-bearing limits on the Earth\'s systems, was not in the original document drawn up by the United Nations, but was included in a European Union submission to talks last week (March 19-23) in New York. Earlier this month, UN secretary general Ban Ki-moon also backed the idea as he presented the report of his High Level Panel on Global Sustainability to an informal plenary of the UN General Assembly on March 17, just before the latest Rio+20 negotiating session began.