Science Weekly

The Lincoln Memorial reflecting pool in Washington DC has hardly been out of the news since April when President Trump vowed to have it renovated, and painted ‘American flag blue’ by 4 July. Despite the pool being stripped, cleaned, coated and refilled, within days the algae that has plagued it for decades was back. To find out why these blooms happen, what makes them so difficult to tackle and what Trump could try next, Ian Sample hears from co-host Madeleine Finlay, and from Dr Linda May, a freshwater ecologist at the UK Centre for Ecology & Hydrology.. Help support our independent journalism at theguardian.com/sciencepod

How much do our genes determine about our lives, and could they influence traits like risk-taking, antisocial behaviour or even violence? Ian Sample talks to Kathryn Paige Harden, a behavioural geneticist and professor of psychology at the University of Texas at Austin who studies how genetic factors shape human behaviour. In her book Original Sin she explores how nature and nurture combine to influence our likelihood of committing crimes, and asks whether the ‘cause’ of our actions matters for how we think about culpability. Help support our independent journalism at theguardian.com/sciencepod

Met Office forecasters have issued a rare red weather warning for England, with temperatures potentially reaching 40C (104F) in some places. Europe is also dealing with a debilitating heatwave, with schools closed, trains cancelled and France even restricting the consumption of alcohol outdoors to take pressure off the emergency services. The high temperatures coincide with the coming El Niño, which some scientists have nicknamed Godzilla for its predicted strength. To find out whether the two are linked, Ian Sample hears from our Europe climate correspondent, Ajit Niranjan. He explains why it’s so hot, why we could be in for even worse and how we can keep as cool as possible. Help support our independent journalism at theguardian.com/sciencepod

Sea ice is melting fast and worsening the climate crisis. But what if there were a way to thicken it again? Madeleine Finlay is joined by environment editor Damian Carrington to discuss a bold attempt to refreeze the Arctic which is showing early signs of success. He visited the project to find out how it will work, how much it will cost and whether it really has potential to improve the fate of the Arctic’s ice. Help support our independent journalism at theguardian.com/sciencepod

The UK prime minister, Keir Starmer, has announced a social media ban for under-16s, as part of an online safety drive that aims to go even further than the world’s first ban, introduced by Australia last year. Many parents have welcomed the proposals, but scientists have pointed to the lack of strong evidence for the efficacy of bans, and some campaigners have argued that the proposal allows social media companies to avoid making meaningful changes on their platforms. Ian Sample is joined by co-host Madeleine Finlay to explore what the evidence indicates about the harms of social media and the impact of banning it outright. Help support our independent journalism at theguardian.com/sciencepod