Author: BBC World Service

As a series of UN climate reports have warned recently, drastic reductions in greenhouse gas emissions – a halving over the next decade – are needed if we are to keep global warming down to manageable levels. No sign of that happening.

An emergency measure to buy time that’s sometimes discussed is solar geoengineering – creating an atmospheric sunscreen that reduces incoming solar heat. Sulphate compounds in volcanic gases or in industrial fumes attract water vapour to make a fine haze and have that effect. The difference would be starting a deliberate programme of injecting sulphate particles into the stratosphere.

There are a host of arguments against it, including a revulsion against adding another pollutant to the atmosphere to offset the one, carbon dioxide, that’s giving us problems in the first place. Another objection, outlined this week, is that it could set back the global fight against malaria - a major killer in its own right. University of Cape Town ecologist Chris Trisos tells Roland Pease what his team’s modelling study revealed.

Yale University neurologist Kevin Sheth talks to us about a revolution in medical scanning – small-scale MRI machines that can be wheeled to the patient’s bedside.

According to palaeontologist Maria McNamara, an amazingly preserved pterosaur fossil from Brazil proves that some of these flying reptiles did have feathers similar to those of birds (and some dinosaurs), and that the feathers were of different colours, possibly for mating display.

Primatologist Adrian Barnett has discovered that spider monkeys in one part of the Brazilian Amazon seek out fruit, full of live maggots to eat. Why?

The ancient Maya flourished in modern day Mexico and Central America for millennia. They built incredible cities and they had sophisticated knowledge of astronomy, architecture and the natural world. But although Maya culture continues to exist today, around 900 AD, many of their great settlements collapsed, and today they lie in ruins.

CrowdScience listener Michael wants to know - how did the Maya sustain their populations successfully for so long? And what happened 1000 years ago that led them to abandon their cities?

To find out, Melanie Brown travels to the forests of Western Belize. She visits the archaeological site of Xunantunich to learn about what life would have been like for the Maya living in what was once a prosperous city. She hears about the importance of water to the Maya way of life in this region, and their ingenious methods for capturing and storing rainfall.

She meets archaeologists using lasers and drones to map Maya settlements that have lain hidden by jungle for centuries. And she discovers what material from the bottom of lakes can tell us about how the Maya faced a changing climate, which may have had huge consequences for their society.

(Photo: Illustration of a mosquito biting Credit: SCIEPRO/Science Photo Library/Getty Images)

Presenters: Roland Pease and Melanie Brown Producers: Andrew Luck-Baker and Anand Jagatia

The ancient Maya flourished in modern day Mexico and Central America for millennia. They built incredible cities and they had sophisticated knowledge of astronomy, architecture and the natural world. But although Maya culture continues to exist today, around 900 AD, many of their great settlements collapsed, and today they lie in ruins.

CrowdScience listener Michael wants to know - how did the Maya sustain their populations successfully for so long? And what happened 1000 years ago that led them to abandon their cities?

To find out, presenter Melanie Brown travels to the forests of Western Belize. She visits the archaeological site of Xunantunich to learn about what life would have been like for the Maya living in what was once a prosperous city. She hears about the importance of water to the Maya way of life in this region, and their ingenious methods for capturing and storing rainfall.

She meets archaeologists using lasers and drones to map Maya settlements that have lain hidden by jungle for centuries. And she discovers what material from the bottom of lakes can tell us about how the Maya faced a changing climate, which may have had huge consequences for their society.

This episode is being released on Earth Day 2022. As we face an uncertain future of our own amid a climate crisis, are there any lessons we can learn from the Maya about how to live sustainably on this planet?

Presented by Melanie Brown and produced by Anand Jagatia

Featuring: Elias Cambranes, Maya expert and tour guide Prof Lisa Lucero, University of Illinois Urbana-Champaign Prof Tim Murtha, University of Florida Dr Eben Broadbent, University of Florida Prof Mark Brenner, University of Florida

Photo: Ancient ruins of the Mayas deep in the forest of Belize Credit: Simon Dannhauer/Getty Images

As a series of UN climate reports have warned recently, drastic reductions in greenhouse gas emissions – a halving over the next decade – are needed if we are to keep global warming down to manageable levels. No sign of that happening.

An emergency measure to buy time that’s sometimes discussed is solar geoengineering – creating an atmospheric sunscreen that reduces incoming solar heat. Sulphate compounds in volcanic gases or in industrial fumes attract water vapour to make a fine haze and have that effect. The difference would be starting a deliberate programme of injecting sulphate particles into the stratosphere.

There are a host of arguments against it, including a revulsion against adding another pollutant to the atmosphere to offset the one, carbon dioxide, that’s giving us problems in the first place. Another objection, outlined this week, is that it could set back the global fight against malaria - a major killer in its own right. University of Cape Town ecologist Chris Trisos tells Roland Pease what his team’s modelling study revealed.

Yale University neurologist Kevin Sheth talks to us about a revolution in medical scanning – small-scale MRI machines that can be wheeled to the patient’s bedside.

According to palaeontologist Maria McNamara, an amazingly preserved pterosaur fossil from Brazil proves that some of these flying reptiles did have feathers similar to those of birds (and some dinosaurs), and that the feathers were of different colours, possibly for mating display.

Primatologist Adrian Barnett has discovered that spider monkeys in one part of the Brazilian Amazon seek out fruit, full of live maggots to eat. Why?

Presenter: Roland Pease Producer: Andrew Luck-Baker

(Photo: Illustration of a mosquito biting Credit: SCIEPRO/Science Photo Library/Getty Images)

Brain scanning experiments reveal how psilocybin works to relieve severe depression. Psilocybin is the psychedelic substance in 'magic mushrooms'. The psychoactive chemical is currently in clinical trials in the UK and US as a potential treatment for depression and other mental illnesses. Professor David Nutt of Imperial College London tells Roland about the research

Also in the show, worrying findings about the increase in premature deaths because of air pollution in growing cities in tropical Africa and Asia. An international group of climatologists has found that the tropical storms which struck Mozambique, Malawi and Madagascar in early 2022 had been made more intense by human-induced climate change. And astronomer David Jewitt used the Hubble telescope to measure the largest known comet in the solar system - it's huge at about 120 kilometres across.

The team at CrowdScience has spent years answering all sorts of listener questions, which must make them pretty smart, right? IN this week’s episode, that assumption is rigorously tested as Marnie Chesterton and the team pit their wits against a multitude of mind-bending puzzles from an old TV game show - all in the name of answering a question from Antonia in Cyprus.

She wants to know: how do we work out how clever someone is? Is IQ the best measure of cleverness? Why do we put such weight on academic performance? And where does emotional intelligence fit into it all?

In the search for answers, presenter Marnie Chesterton and the team are locked in rooms to battle mental, physical, mystery, and skill-based challenges, all against the clock. Unpicking their efforts in the studio are a global team of cleverness researchers: Dr. Stuart Ritchie from Kings College London, Professor Sophie von Stumm from York University, and Dr. Alex Burgoyne, from the Georgia Institute of Technology in the US.

They are challenged to face the toughest questions in their field: Why do men and women tend to perform differently in these tests? Is our smartness in our genes? And what about the Flynn effect – where IQs appear to have risen, decade after decade, around the world.

(Image: Mexican Psilocybe Cubensis. An adult mushroom raining spores. Credit: Getty Images)

The team at CrowdScience have spent years answering all sorts of listener questions, which must make them pretty smart, right? IN this week’s episode, that assumption is rigorously tested as Marnie Chesterton and the team pit their wits against a multitude of mindbending puzzles from an old TV gameshow - all in the name of answering a question from Antonia in Cyprus.

She wants to know: how do we work out how clever someone is? Is IQ the best measure of cleverness? Why do we put such weight on academic performance? And where does emotional intelligence fit into it all?

In the search for answers, presenter Marnie Chesterton and the team are locked in rooms to battle mental, physical, mystery and skill-based challenges, all against the clock. Unpicking their efforts in the studio are a global team of cleverness researchers: Dr Stuart Ritchie from Kings College London, Professor Sophie von Stumm from York University and Dr Alex Burgoyne, from Georgia Institute of Technology in the US.

They are challenged to face the toughest questions in their field: Why do men and women tend to perform differently in these tests? Is our smartness in our genes? And what about the Flynn effect – where IQs appear to have risen, decade after decade, around the world.

Produced by Marnie Chesterton on BBC World Service

[Image: Man doing puzzle. Credit: Getty Images]

Brain scanning experiments reveal how psilocybin works to relieve severe depression. Psilocybin is the psychedelic substance in 'magic mushrooms'. The psychoactive chemical is currently in clinical trials in the UK and US as a potential treatment for depression and other mental illnesses. Professor David Nutt of Imperial College London tells Roland about the research

Also in the show, worrying findings about the increase in premature deaths because of air pollution in growing cities in tropical Africa and Asia. An international group of climatologists has found that the tropical storms which struck Mozambique, Malawi and Madagascar in early 2022 had been made more intense by human-induced climate change. And astronomer David Jewitt used the Hubble telescope to measure the largest known comet in the solar system - it's huge at about 120 kilometres across.

(Image: Mexican Psilocybe Cubensis. An adult mushroom raining spores. Credit: Getty Images)

Presenter: Roland Pease Producer: Andrew Luck-Baker

Just over two months ago, the undersea volcano of Hunga Tonga erupted catastrophically, generating huge tsunamis and covering the islands of Tonga in ash. University of Auckland geologist Shane Cronin is now in Tonga, trying to piece together the sequence of violent events.

Edinburgh University palaeontologist Ornella Bertrand tells us about her studies of the ancient mammals that inherited the Earth after the dinosaurs were wiped out. To her surprise, in the first 10 million years after the giant meteorite struck, natural selection favoured larger-bodied mammals, not smarter ones.

At the University of Bristol, a team of engineers is developing skin for robots, designed to give future bots a fine sense of touch. Roland shakes hands with a prototype.

A global satellite survey of the world’s largest coastal cities finds that most of them contain areas that are subsiding faster than the rate that the sea level is rising. Some cities are sinking more than ten times faster, putting many millions of people at an ever-increasing risk of flooding. Oceanographer Steven D’Hondt at the University of Rhode Island explains why this is happening.

The odds of becoming a fossil are vanishingly small. And yet there seem to be an awful lot of them out there. In some parts of the world you can barely look at a rock without finding a fossil, and museum archives worldwide are stuffed with everything from ammonites to Archaeopteryx. But how many does that leave to be discovered by future fossil hunters? What’s the total number of fossils left to find?

That’s what listener Anders Hegvik from Norway wants to know and what CrowdScience is off to investigate. Despite not having the technology or time to scan the entire planet, presenter Marnie Chesterton prepares to find a decent answer. During her quest, she meets the scientists who dig up fossils all over the world; does some very large sums; and asks whether we'll ever run out of the very best and most exciting fossil finds.

(Image: An eruption occurs at the underwater volcano Hunga Tonga-Hunga Ha"apai off Tonga, January 14, 2022. Credit: Tonga Geological Services/via Reuters)

The odds of becoming a fossil are vanishingly small. And yet there seem to be an awful lot of them out there. In some parts of the world you can barely look at a rock without finding a fossil, and museum archives worldwide are stuffed with everything from ammonites to Archaeopteryx. But how many does that leave to be discovered by future fossil hunters? What’s the total number of fossils left to find?

That’s what listener Anders Hegvik from Norway wants to know and what CrowdScience is off to investigate. Despite not having the technology or time to scan the entire planet, presenter Marnie Chesterton prepares to find a decent answer. During her quest, she meets the scientists who dig up fossils all over the world; does some very large sums; and asks, have we already found all the T-rexes out there?

Presented by Marnie Chesterton and produced by Anna Lacey

(Photo: Fossilized dinosaur bones and skull in the send. Credit: Getty Images)

Just over two months ago, the undersea volcano of Hunga Tonga erupted catastrophically, generating huge tsunamis and covering the islands of Tonga in ash. University of Auckland geologist Shane Cronin is now in Tonga, trying to piece together the sequence of violent events.

Edinburgh University palaeontologist Ornella Bertrand tells us about her studies of the ancient mammals that inherited the Earth after the dinosaurs were wiped out. To her surprise, in the first 10 million years after the giant meteorite struck, natural selection favoured larger-bodied mammals, not smarter ones.

At the University of Bristol, a team of engineers are developing skin for robots, designed to give future bots a fine sense of touch. Roland shakes hands with a prototype.

A global satellite survey of the world’s largest coastal cities finds that most of them contain areas that are subsiding faster than the rate that the sea level is rising. Some cities are sinking more than ten times faster, putting many millions of people at an ever-increasing risk of flooding. Oceanographer Steven D’Hondt at the University of Rhode Island explains why this is happening.

(Image: An eruption occurs at the underwater volcano Hunga Tonga-Hunga Ha"apai off Tonga, January 14, 2022. Credit: Tonga Geological Services/via Reuters)

Presenter: Roland Pease Producer: Andrew Luck-Baker