In Northern Ireland, Barra meets the team investigating the promising possibility that a slippery substance found in plentiful supply around the country's coast could help reduce the methane output of cows – a major agricultural source of greenhouse gases.The moose's turn as an unlikely Swedish reality TV star is helping shine a light on the species' plight. A deep dive below the surface of a German lake reveals the spectacular natural miracle being aided by a group of volunteers.By Rome's historic Villa Borghese, Barra hears how a creature synonymous with the eternal city is now making a return to its parks and streets.In Spain, a farmer reveals how she's learning to love the infamous vulture, which benefits the area by helping sanitise forests and hillsides.