Hydrogen (H) - water (part 2)

As climate change threatens to play havoc with the rain, could we instead draw our water directly from the ocean?

In his second gulp of H2O, presenter Justin Rowlatt hears from climatologist Raymond Pierrehumbert about how global warming is causing drastic but often unpredictable disruption to our natural supplies of freshwater.

Yet as Israel enters its third year of dought, few of the country's citizens are aware of any water shortages. The BBC's Shira Gemer reports on the technological breakthroughs that have made this possible - from the gigantic Sorek desalination plant, to the drip irrigation pioneered by Netafim in the Negev desert.

We also hear from desalination expert Raphael Semiat of Technion University how much the rest of the world can emulate Israel's success.

(Picture: Icebergs float in the Jacobshavn Bay in Greenland; Credit: Uriel Sinai/Getty Images)