The first significant step to putting the Paris Climate Agreement into practice will take place at the UN on Friday when over 150 nations are expected to formally sign the deal.

A group of world leaders and international finance chiefs has urged the world to rapidly expand the pricing of carbon pollution.

The ground convulsion resulting from North Korea's underground nuclear bomb test in January has been mapped by Europe's Sentinel-1a radar satellite.

The zero-fuel aeroplane, Solar Impulse, renews its effort to circumnavigate the globe, leaving Hawaii to fly across the Pacific Ocean to San Francisco.