The Inter-Governmental Conference on the Convention on the Dumping of Wastes at Sea, which met in London in November 1972 at the invitation of the United Kingdom, adopted this instrument, generally known as the London Convention. The London Convention, one of the first international conventions for the protection of the marine environment from human activities, came into force on 30 August 1975. Since 1977, it has been administered by IMO.
The London Convention contributes to the international control and prevention of marine pollution by prohibiting the dumping of certain hazardous materials. In addition, a special permit is required prior to dumping of a number of other identified materials and a general permit for other wastes or matter.
"Dumping" has been defined as the deliberate disposal at sea of wastes or other matter from vessels, aircraft, platforms or other man-made structures, as well as the deliberate disposal of these vessels or platforms themselves. Annexes list wastes which cannot be dumped and others for which a special dumping permit is required.
Amendments adopted in 1993 (which entered into force in 1994) banned the dumping into sea of low-level radioactive wastes. In addition, the amendments phased out the dumping of industrial wastes by 31 December 1995 and banned the incineration at sea of industrial wastes.
In 1996, Parties adopted a Protocol to the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, 1972 (known as the London Protocol) which entered into force in 2006.
The Protocol, which is meant to eventually replace the 1972 Convention, represents a major change of approach to the question of how to regulate the use of the sea as a depository for waste materials. Rather than stating which materials may not be dumped, it prohibits all dumping, except for possibly acceptable wastes on the so-called "reverse list", contained in an annex to the Protocol.
The London Protocol stresses the “precautionary approach”, which requires that “appropriate preventative measures are taken when there is reason to believe that wastes or other matter introduced into the marine environment are likely to cause harm even when there is no conclusive evidence to prove a causal relation between inputs and their effects”.
It also states that "the polluter should, in principle, bear the cost of pollution" and emphasizes that Contracting Parties should ensure that the Protocol should not simply result in pollution being transferred from one part of the environment to another.
The Contracting Parties to the London Convention and Protocol have recently taken steps to mitigate the impacts of increasing concentrations of CO2 in the atmosphere (and consequently in the marine environment) and to ensure that new technologies that aim to engineer the climate, and have the potential to cause harm to the marine environment, are effectively controlled and regulated. The instruments have, so far, been the most advanced international regulatory instruments addressing carbon capture and sequestration in sub-sea geological formations and marine climate engineering such as ocean fertilization.
The 1996 Protocol restricts all dumping except for a permitted list (which still require permits).
Article 4 states that Contracting Parties "shall prohibit the dumping of any wastes or other matter with the exception of those listed in Annex 1."
The permitted substances are:
1. Dredged material
2. Sewage sludge
3. Fish waste, or material resulting from industrial fish processing operations
4. Vessels and platforms or other man-made structures at sea
5. Inert, inorganic geological material
6. Organic material of natural origin
7. Bulky items primarily comprising iron, steel, concrete and similar unharmful materials for which the concern is physical impact and limited to those circumstances, where such wastes are generated at locations, such as small islands with isolated communities, having no practicable access to disposal options other than dumping.
8. CO2 streams from CO2 capture processes.(added under the amendments adopted in 2006, which entered into force in 2007).