The US has withdrawn from a historic nuclear disarmament treaty. However the verification of such treaties has been under scrutiny for some time as they don’t actually reveal the size of nuclear stockpiles.
New methods of verification and encryption should allow all sides to be more confident on who has what in terms of nuclear stockpiles.

Can carbon capture and storage technology help reduce atmospheric Co2 levels? The answer seems to be yes, but at a considerable cost.

And we go for a cold swim around some hydrothermal vents.


Photo: U.S. President Donald Trump and Russian President Vladimir Putin. Credit: Sputnik/Reuters

Presenter: Roland Pease
Producer: Julian Siddle