The global concentration of carbon dioxide in Earth's atmosphere reaches 350 ppm (parts per million) by volume. The level of 350ppm is regarded by James Hansen as the maximum permissible level that will avoid a climate tipping point.[1]
The Tasman Accord was signed in New Zealand by Tasman Forestry Ltd, environmental groups and the Government.
The first national park in the Netherlands is established in Schiermonnikoog.
The Montreal Protocol on Substances that Deplete the Ozone Layer (a protocol to the Vienna Convention for the Protection of the Ozone Layer) comes into force. It is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion.