Nick Kwek visits Austin, Texas, to meet some of the key voices and innovators at this year's SXSW Festival. Paul Carter heads behind the scenes of FC Barcelona's renovated stadium as it reopens to the public. Yasmin Morgan-Griffiths finds out how research linking climate change and extreme weather events is being used in lawsuits against major polluters. Plus, Martin Sharkey takes us on a journey into the history of the emoji.