Answer: Please see expalanation column for answer
Explanation: Beginning with with most recent, we have
The explosion of the Deep water Horizon---April 20,2010
The drafting of the Kyoto Protocol--- December 11 1997
The oil spill of the Exxon Valdez--- March 24, 1989
The ratification of the Montreal Protocol, 16 Septemnber, 1987
The meltdown of the reactor at Chernobyl---April 26,1986
The leak of methyl isocyanate in Bhopal--- 2 December, 1984
The discovery of contamination at Love Canal,--- June 19 1978
The passage of the US Endangered Species Act. - Dec 28 1973
The first Earth Day----- April 22, 1970
