Early in his career, a scientist named Mario J. Molina was pulled into seemingly obscure research about strange chemicals being spewed into the atmosphere. Within a year, he had helped discover a global environmental emergency, work that would ultimately win aNobel Prize.

This spring, construction is set to begin on the first projects coordinated through Power Africa, a multibillion-dollar Obama administration initiative that seeks to double access to electricity in sub-Saharan Africa within five years, and in some cases accelerate reforms in the governments of the nations involved. Among the initial projects are wind farms in Kenya and Tanzania, and a solar project in Tanzania.

The approved budget for United Nations peacekeeping operations from July 2013 to June 2014 runs to $7.83 billion—$390 million higher than in the previous year.1 (See Figure 1.) This is the third-highest budget since the record $8.26 billion spent in 2009–10.2 Despite some relatively minor fluctuations in the last seven years, peacekeeping budgets are much more stable now than in the 1990s, when a rapid rise in spending was followed by an abrupt decline.

A long-awaited UN report on how to curb climate change says the world must rapidly move away from carbon-intensive fuels.

There must be a "massive shift" to renewable energy, says the study released in Berlin.

It has been finalised after a week of negotiations between scientists and government officials.

Natural gas is seen as a key bridge to move energy production away from oil and coal.

But there have been battles between participants over who will pay for this energy transition.