Her investigations of wildfires around times of mass extinction in the earth's history have challenged previous assumptions about the planet at critical times when extraordinary numbers of species were wiped off the record.
Most recently, Dr Belcher's discoveries have somewhat snuffed the notion that oxygen levels in the air plummeted to around 12 per cent (compared to the present 21 per cent) during a mass extinction 200 million years ago. How did she work that out? It's thanks to the fossil record, where the presence of charcoal indicates that plant material had burned. "To have a fire you need a sufficient amount of oxygen in the atmosphere. Charcoal itself is formed in low oxygen but this is because a fire burns once it has enough oxygen and it eliminates oxygen in its base, which then causes it to form the charcoal.
So we can use charcoal in the fossil record as a proxy for wildfires," she explains. The Marie Curie post-doctoral fellow has been looking at charcoal in rocks from Greenland that date from the Triassic-Jurassic (T-J) boundary 200 million years ago, when a mass extinction event saw enormous biodiversity loss of 50 per cent in marine invertebrate species and 95 per cent for terrestrial plant species in Northern Europe. Meanwhile 42 per cent of terrestrial vertebrate families in North America died out.
Previous work by UCD's Dr Jennifer McElwain - who collected the Greenland material when she was based at The Field Museum in Chicago - shows a global rise in temperature and carbon dioxide over that period, and Dr Belcher's work builds on that picture.
"I'm looking at the charcoal to help identify periods when there was low oxygen," explains Dr Belcher, describing how a drop in atmospheric oxygen levels has been put forward as a possible theory in the T-J mass extinction.
Dr Claire Belcher of UCD School of Biology and Environmental Science, seen here inside the purpose-built chamber, wearing a breathing apparatus
As part of her experiments, she has been trying to burn material at different levels of atmospheric oxygen in room-sized chambers where she can tightly control conditions. Getting pine needles and moss to burn without using matches or an accelerant was tougher than she expected, and her work suggests that for lightning to spark wildfires around the T-J mass extinction, oxygen would have had to be more plentiful than previously assumed.
"Previous work has put the lower limit for combustion at about 12 or 13 per cent, those are the figures out there. But we have revised this based on what we feel are more realistic situations for burning to being closer to 15 per cent, or perhaps even higher, 17 per cent to get frequently occurring fires," says Dr Belcher, whose work was published in Science earlier this year.
Of course even a drop in oxygen to 15-17 per cent would still be a problem, notes Dr Belcher. "I had to wear breathing apparatus under 18 per cent oxygen," she says. "Some animals, particularly reptiles and amphibians fare particularly badly in lower oxygen environments, especially when it's so warm. So even a slight drop in oxygen from our present day ambient level would cause quite a lot of problems for many animals."
Dr Belcher also explains that so far her approach has sampled periods in the fossil record that are relatively far apart, so she doesn't rule out that oxygen may have dipped further over shorter time-scales. That's why she is currently looking at charcoal traces at closer time points in the Greenland record to see if gaps could pinpoint times when fires became scarcer.
Dr Belcher's work forms part of a multipronged approach, with UCD colleagues looking at carbon dioxide levels, pollen and changes in leaf fossils over the T-J boundary, as well as experiments to test how ancient plant species that still exist today respond to environmental stress.
Ultimately they hope that knowing more about a global catastrophe of old can inform current strategies to mitigate the effects of global warming.
"We are looking at the boundary to see how the vegetation coped with that global warming, and to see how we may be able to mediate against this and ecosystems changing in the world today," says Dr Belcher.
And while her recent data have shaken up previous notions about oxygen, it's not the first time that Belcher has used fire to shed new light on old thinking about mass extinction.
Her doctoral thesis at Royal Holloway University of London took the heat out of theories that the "dinosaur killer" asteroid 65 million years ago sparked global wildfires. She looked at fire evidence in the fossil record across the US and Canada, sampling rocks at points moving away from the crater in Mexico where the asteroid hit.
"Previously people thought that there were global wildfires but I actually found less fire at the boundary than after, so it suggested that that thermal radiation wasn't powerful enough to ignite wildfires," she says. "And previous estimates for ground temperatures were 800 to 1000 degrees Centigrade, but my work revised that to about 325 to 545 degrees at the very most. Which is still plenty hot enough."
"It's interesting trying to unravel the things that have led to evolution and extinction of life and better understanding the earth's system," she says. "Fire is generally not something people pay much attention to, but it has much more feedback to the earth's system than most people realise. It releases toxins and carbon dioxide and it denudes landscape, and all those things cause more effects than people realise.
So I want to look at fire's effects on biogeochemical cycling, which hopefully people will then be able to build into models of atmospheric oxygen and carbon dioxide to improve them."