The United States Supreme Court rules that the Environmental Protection Agency has the authority to regulate the emission of greenhouse gases and must do so unless it can provide some scientific reason proving otherwise.
Ministers from natural gas exporting countries such as Russia, Kazakhstan and Iran meet in Doha, Qatar, prompting speculation that they might be looking at transforming the Gas Exporting Countries Forum into a cartel similar to OPEC.
Ice hockey: The 2007 NHL Stanley Cup Playoffs begin. The inaugural matchup features the Pittsburgh Penguins visiting the Ottawa Senators at Scotiabank Place in Ottawa, Ontario.
Wal-Mart retakes the #1 position on the 2007 Fortune 500 list with US$351.1 billion in revenue for F/Y 2006, beating previous #1 ExxonMobil by $3.9 billion.
The G4 group of nations, which includes Brazil, India, Germany and Japan, says that it would revive efforts for United Nations Security Council reform.
Saudi Arabia arrests 172 terrorist suspects in a series of raids after uncovering a plot to carry out suicide air attacks on oil and military installations. $32.4m in cash was also uncovered, as were many weapons.