Liz Truss and Rishi Sunak have clashed on a number of issues as they battle to become the next prime minister. However, as heated debates hit our television screens, the climate emergency has been alarmingly absent from discussions. Ian Sample chats to Guardian environment correspondent Fiona Harvey about which candidate is ‘least bad’ when it comes to green policies, and why one of the world’s most urgent issues has taken a back seat in the leadership contest. Help support our independent journalism at theguardian.com/sciencepod

The impacts of the climate crisis are undeniably here. Heatwaves, droughts, wildfires and flooding are causing devastation around the world. And yet, we still aren’t seeing the drastic action that’s required to avert climate disaster. As things get worse, it’s easy to give up hope – but ‘climate doomism’ is just as dangerous as climate denial. Anand Jagatia speaks to psychotherapist Caroline Hickman about her research on climate anxiety, and how we can turn feelings of doom into positive action. Help support our independent journalism at theguardian.com/sciencepod

US president Joe Biden campaigned on climate issues, but recent events may have sounded a death knell for his promises. Last week, his attempts to pass sweeping climate legislation were thwarted – by a senator in his own party. And in June, a landmark US Supreme Court ruling has greatly limited the federal government’s ability to regulate emissions from the fossil fuel industry. So where does that leave the Democrats’ climate plans? Ian Sample speaks to Prof Elizabeth Bomberg about what these developments mean for the Biden administration and the rest of the world. Help support our independent journalism at theguardian.com/sciencepod

The H5N1 strain of avian influenza is sweeping across the world, killing millions of birds. In the UK, it’s causing disastrous losses of seabirds – populations that were already being hit by a number of threats, including habitat loss, overfishing and global heating. Biodiversity reporter Phoebe Weston tells Madeleine Finlay about how the virus made it into wild birds, why it’s having such a devastating impact, and the long-term impact bird flu could have on some of our most vulnerable species. Help support our independent journalism at theguardian.com/sciencepod

This week, Nasa unveiled the first images from the James Webb space telescope – much awaited pictures that show our universe in glorious technicolour. The $10bn telescope, now 1 million miles from Earth, will allow scientists to look back to the dawn of time. Prof Ray Jayawardhana, who is working with one of the instruments onboard the JWST, speaks to Ian Sample about what these images show us, and what they mean for the very human quest of discovering our place in the cosmos.. Help support our independent journalism at theguardian.com/sciencepod

The varroa mite, a deadly honeybee parasite, has finally found its way into Australia. Varroa destructor affects every other major beekeeping area in the world, damaging honeybees and transmitting viruses across hives. Now, in a fight to contain the mite, the state of New South Wales has destroyed 1,533 infected hives and implemented a statewide standstill on bee movement. Madeleine Finlay speaks to Dr Cooper Schouten, a beekeper and researcher, about why the mite poses such a threat to honeybees, what it means to put bees into lockdown, and what impacts this biosecurity breech could have.. Help support our independent journalism at theguardian.com/sciencepod

The US supreme court’s decision to overturn Roe v Wade will have a significant impact on the reproductive health and the safety of women who become pregnant in the US. Researchers have estimated it could increase maternal mortality in the country by 20%. The ruling also sparked debates around men’s reproductive options, including the role of vasectomies in pregnancy and abortion prevention. Madeleine Finlay speaks to historian Georgia Granger about the history of vasectomies, why they’ve ended up as part of the conversation about women’s reproductive rights, and hears why male sterilisation won’t solve America’s abortion problem. Help support our independent journalism at theguardian.com/sciencepod

The UK is yet again facing a wave of Covid infections, with cases soaring by more than half a million in a week at the end of June. This time, the wave is driven by even more transmissible variants of Omicron known as BA.4 and BA.5. But with all Covid precautions gone, and many of us heading to bars, pubs, festivals and sporting events as the summer rolls on, is it much of a surprise? Ian Sample asks Prof Graham Medley if infections will translate into hospitalisations and deaths, and whether we can expect ongoing cycles of Covid waves in the months and years to come. Help support our independent journalism at theguardian.com/sciencepod

Last week, public health officials declared a ‘national incident’ after they found vaccine-derived poliovirus in London sewage samples. No cases of polio symptoms have been reported but there is evidence the virus is spreading. So what does it mean to have found the virus almost 20 years after the UK was declared polio-free? Ian Sample speaks to epidemiologist Nicholas Grassly to find out how worried we should be and what it means for the global effort to eradicate polio.. Help support our independent journalism at theguardian.com/sciencepod

When the Guardian’s UK technology editor Alex Hern was contacted on Twitter to ask if he was involved in a new cryptocurrency called Tsuka, he assumed they just wanted him to buy it. He ignored the messages. But soon after Alex realised that, without knowing it, he was already involved. What happened next reveals a lot about the strange world of ‘shitcoins’ – cryptocurrencies with no reason for existence beyond buying low and selling high. Madeleine Finlay speaks to Alex Hern about his shitcoin saga, and how the lines can get blurred between a gamble and a scam. Help support our independent journalism at theguardian.com/sciencepod