"The world is close to reaching tipping points that will make it irreversibly hotter, making this decade critical in efforts to contain global warming, scientists warned on Monday."

"There is a particularly sensitive accusation reverberating through online discussion boards and social media in Japan: that Emperor Akihito's speech on the one year anniversary of the earthquake and tsunami was censored on TV for his comments about the nuclear disaster at Fukushima."

"Extreme weather events over the past decade have increased and were 'very likely' caused by manmade global warming, a study in the journal Nature Climate Change said on Sunday."

"World leaders may pledge tighter controls over nuclear materials to keep them out of the hands of terrorists, according to the draft of a communique to be released at the end of their two-day meeting in Seoul."

"Securing vulnerable nuclear material before the next Nuclear Security Summit in 2014 is the top priority, according to a copy of the six-page working document obtained by Bloomberg News. The draft, completed at a March 23 meeting of nuclear advisers attending the meetings in the South Korean capital, will be subject to debate at the gathering that ends tomorrow.

"The cost of damage to the world's oceans from climate change could reach $2 trillion a year by 2100 if measures to cut greenhouse gas emissions are not stepped up, a study by marine experts said on Wednesday."

"Fresh water supplies are unlikely to keep up with global demand by 2040, increasing political instability, hobbling economic growth and endangering world food markets, according to a U.S. intelligence assessment released on Thursday."

"The same follow-the-money approach used to catch drug kingpins and human traffickers could be used to track down the big operators behind large-scale illegal logging, the World Bank said on Tuesday."

"For centuries, the daredevils known as submariners have slipped beneath the waves in vehicles made for horizontal travel. Their craft are basically underwater ships. Even submersibles, small vessels that dive unusually deep, follow the horizontal plan. Until now."

A nonfiction reporter takes a long look at Walmart's suppliers in China and elsewhere, assessing the company's claims to be greening itself as the world's largest retailer.

"An iPhone can do a lot of things. But can it arm Congolese rebels?

That is the question being debated by a battalion of lobbyists from electronics makers, mining companies and international aid organizations that has descended on the Securities and Exchange Commission in recent months seeking to influence the drafting of a Dodd-Frank regulation that has nothing to do with the financial crisis."