Transcript

3.5.26 · Science Show KY

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Speaker 1: This is Radio wi's Diary of Science and Nature. I'm
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Kelly Taylor. I'll be your reader with stories on the
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topics of science and nature. But first a reminder that
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RADIOI is a reading service intended for people who are
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blind or have other disabilities that make it difficult to
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read printed material. We'll start off today with an article
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from Vox and the headline is scientists have been underestimating
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sea levels for decades dated March fourth. Humans are a
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coastal species. More than one in ten people in the
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world live within three miles of the shore, and about
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forty percent of us live within an hour's drive of
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the ocean. These shoreline regions generate a massive force in
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the global economy. In the US alone, coastal counties account
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for one third of the gross domestic product. But the
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same oceans that draw so many people near them pose
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a threat when the water rises and pours inland during
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tidal floods or storm surges. Water is often the deadliest,
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most destructive, and costliest element of many natural disasters, and
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with coastal populations growing, the economic toll of disasters in
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coastal areas is increasing, especially as sea levels rise due
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to climate change. Already, global average sea levels have increased
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around nine inches since eighteen eighty, one of the most
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tangible impacts of a warming world. As ice sheets melt
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and the ocean expands. Sea levels are rising in some
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places faster than others, particularly as land subsides. So it's
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alarming then that in many of the most populated parts
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of the world, we've been significantly underestimating the level of
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the sea, a basic consequential fact of life on the coast.
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That's the conclusion of a new study published today in
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the journal Nature. On average, conventional estimates of the height
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of the ocean are about one foot too low, though
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in some parts of the world the error is more
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than three feet. These apparent errors aren't just a scientific question.
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Sea level estimates are used to create hazard maps that
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govern where people live, where protective barriers get built, and
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whether insurance companies will offer protection for your home. The
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fact that we have this wrong means some of our
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infrastructure may already be facing more threats from the ocean
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than we were expecting. Add to this miscalculation the fact
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that further warming is now locked in thanks to the
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greenhouse gases we've already emitted, which will inexorably lead to
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rising seas, and we're looking at a scenario where tens
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of millions more people face threats to their lives and
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livelihoods in the coming decades. By twenty one hundred, global
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average sea levels are projected to rise additionally and average
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between nine inches and more than three feet, largely depending
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on how quickly we reduce carbon emissions. That's on top
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of the underestimated sea levels outlined in the study. The
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result is that many people may not know how vulnerable
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they are today and how much more danger they face
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in the future. It may seem bizarre that so many
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researchers could be wrong for so long about something so fundamental,
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but measuring global sea levels is surprisingly complicated. You can't
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just stick a ruler in the ocean. The water is
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constantly moving with the waves, as well as rising and
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falling with the tides. Land can also sink over time,
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even if you manage to get a decent average measurement
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in one location translate to other places. The planet is round,
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but not a perfect sphere, which means gravity doesn't act evenly.
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It's also rotating. It also rotating, making it bulge along
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the equator. The water itself throughout the oceans has different
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salt concentrations in temperatures, which alter its density, and winds
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can push the surface of the ocean and cause it
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to pile up in some areas and thin out in others.
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The end result is that sea levels vary around the
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world and even across countries. In the United States, the
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sea level is higher on the west coast of the
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US than on the East coast. What does scientists do
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when they're faced with a system as fiendishly complex as
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the oceans. They use a simplified model, in this case,
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one of the Earth called agoid, that simulates where the
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oceans would settle if they were only under the force
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of gravity and Earth's rotation, disregarding factors like currents and winds.
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This geoid model, often constructed from satellite data, is used
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as a reference level for land and sea elevation. What
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the geoid model doesn't do is include actual sea level measurements.
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The whole process simplifies the math, but it leaves a
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lot of critical information out, particularly when you zoom into
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specific regions. Katharina Seeger, a co author of the new study,
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saw this discrepancy at work in her studies of the
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Ayrwaddy Delta in me and Maar, where there was sparse
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mapping of lowlands vulnerable to flooding, making it difficult to
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predict where the waters will rise during regular monsoon rains
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and storm surges. Philip Menderhood, a scientist at the Wagoning One,
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Innigan University in Research who co authored the study, saw
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something similar when he was researching land subsidence in Vietnam's
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Mekong River Delta, an area that routinely floods. Quote. Being
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in the delta itself, I witnessed there that the water
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levels were much higher than those maps implied. Menderhood said.
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Their experiences spurred them to investigate whether there were similar
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discrepancies in other parts of the world and if there
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was a bigger underlying problem. What started as a side
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project ended up becoming the focus of years of research.
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Seger and Menderhood looked at coastal impact assessments around the
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world in three hundred and eighty five peer reviewed articles
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between two thousand and nine and twenty twenty five. They
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found that calculations of land elevation from the geoid sea
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level didn't line up with the direct measurements of sea level.
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In fact, more than ninety percent of coastal hazard assessments
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to bend Hood and Seger looked at underestimated coastal sea
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levels because they didn't correct their goid calculations with direct
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local sea level measurements. The scale of the errors wasn't
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evenly spread around the world. Regions like North America and
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Europe had more local measurements and thus had smaller gaps
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between their assumed sea level and the actual sea level.
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The largest discrepancies were in less well studied regions, including
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densely populated island countries like Indonesia the Philippines. The findings
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are pretty stunning, says a Torbjorn Tornkivist, a professor of
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Earth and Environmental science at Tulane University, was not involved
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in the study. Quote we've dropped the ball a little bit.
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It's such a basic thing that a lot of us
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haven't really paid much attention to. Quote. Now we'll turn
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to BBC Science Focus magazine, dated February twenty eight. Something
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very strange is happening under Greenland's ice. The ice deep
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underneath Greenland seems to be slowly churning into bizarre plume
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like swirls. According to a recent paper, understanding this strange
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process could help researchers better predict how Greenland's ice is
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behaving while it rapidly melts into the sea. The formations
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were first spotted in twenty fourteen using radar imaging, but
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how they formed remained unclear. Now researchers suggest the answer
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lies in thermal convection, the same force that pushes and
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pulls Earth's red hot mantle. We often think of ice
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as a solid material, cold and rigid, said professor Andreas
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Bourne from the University of Bergen in Norway. So the
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fact that we discovered that parts of the Greenland ice
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sheet undergo thermal convection, almost like a pot of boiling
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pot fasta is pretty wild and fascinating. In quote, convection
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happens when hotter parts of a material rise and cooler
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parts sink in a slow cyclical movement. In this case,
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the plumes seem to have formed in the solid ice
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over thousands of years, caused by heat rising from deep
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inside Earth. Quote. The fact that thermal convection can occur
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inside an ice sheet is a bit counterintuitive, said first
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author doctor Robert Law from Zurich, Switzerland. But since ice
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is at least a million times softer than Earth's mantle,
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the physics actually makes sense to understand whether convection could
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feasibly produce the mysterious plumes. Law and his team recreated
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a digital version of Greenland's ice sheet with a computer
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model that's usually used to simulate convection in Earth's mantle.
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After tweaking variables such as ice the thingckness, softness, and movement,
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the model began to form rising columns of ice swirling
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into shapes that resembled those in the Greenland ice sheet.
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Law told BBC Science Focus that the relatively stable, low
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snowfall conditions found in northern Greenland seemed to provide the
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perfect insulation layer to encourage these shapes to form over
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thousands of years. But the study also allowed the scientists
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to understand more about the properties of ice that would
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otherwise be difficult to measure. Quote it's really challenging to
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gather information on ice properties, particularly those deep in the
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ice sheet, explained Law. Quote approaches like this can provide
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really valuable information we wouldn't gather from other sources. Our
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results suggest that ice is actually softer and more sensitive
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to stress than commonly thought, though we need further studies
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to be absolutely certain about this. That's important ordan because
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the Greenland ice sheet is huge, estimated to be more
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than one point seven million square kilometers or six hundred
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and fifty thousand square miles. If the entire sheet melted,
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it would raise sea levels by twenty four feet, according
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to estimates from the US Snow and Ice Data Center.
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Another recent study, this time led by the University of Barcelona,
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has shown that the ice is melting at unprecedented levels. Quote.
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The Greenland ice sheet is experiencing more frequent, larger and
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more intense extreme melt events than in the past, says
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first author doctor Joseph Bonsom's geography researcher at Barcelona. Quote.
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Most of the top ten extreme melting years have occurred
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since two thousand. As one of the largest sources of
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frozen water on Earth, the melting of Greenland makes a
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significant contribution to global sea level rise and adds urgency
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to international climate action law. Told BBC Science Focus what
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his study meant for the future of Greenland and the
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wider climate. Quote. On their own, the plumes Art assign
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that we should expect the ice sheet to decay faster
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than presently anticipated. They're like an ancient artifact, a thicker, colder, drier,
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and more stable ice sheet from the last ice age. However,
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ice physics remains poorly understood. Every advance in physical understanding
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allows us to better predict the rates of ice sheet
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melt and sea level rise. Quote Law added that he
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hoped people who came across his research would be filled
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with the same awe at nature and the Greenland ice
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sheet as his team was when they conducted their research. Now,
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let's go to popular science. Mosquitoes have been sucking our
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blood for one point eight million years, is stated February
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twenty sixth Mosquitoes are undeniably the deadliest animals to humans.
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Malaria infections carried by the insects still kill over six
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hundred thousand people every year, while around half the world's
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population remains at risk of exposure despite significant medical advances. Meanwhile,
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mosquito saliva regularly spreads a number of other dangerous diseases,
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including West Nile virus, dingay fever, and various forms of encephalitis.
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Not all mosquitoes are to blame, however, every blood sucking
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malaria vector comes from those within the group anophilees leucosphorous,
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which encompasses a comparatively small portion of the planet's roughly
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thirty five hundred known mosquito species. So when and why
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did humans fall prey to such a pernicious threat. Based
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on recent genetic analysis, the deadly saga started when early
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hominins migrated into Southeast Asia around one point eight million
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years ago. The evidence is detailed in an international research
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team's study published today in the journal's Scientific Reports. To
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investigate the issue, biologists sequenced DNA from thirty eight mosquitoes
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spanning eleven different species in the Leucosporus group collected from
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Southeast Asia between nineteen ninety two and twenty twenty. They
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used computer models to estimate the long term rates of
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DNA mutation and construct larger revolutionary histories of the insects.
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According to their analysis, a taste or human blood developed
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only once within the Leucosporus group, somewhere between two point
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nine and one point six million years ago, specifically in Sundaland,
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a region encompassing Borneo, Java, the Melee Peninsula, and Sumatra.
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Before this mutation, mosquitos were perfectly content to feed on
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the other nearby non human primates. The studies authors noted
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that this aligns with paleo anthropologists' earliest proposed date for
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Homo Erectus arriving in Sundaland about one point eight million
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years ago. Modern humans didn't arrive in the region until
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seventy six thousand to sixty three thousand years ago, giving
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mosquitoes plenty of time to develop their preference for hominins.
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But these findings also pre date most past histories of
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insect evolution, particularly for African malaria transmitters like Anophiales gambia
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and Anophales coolutsii. Prior to these recent genetic discoveries, researchers
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believed human feeding only started between five hundred and nine
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thousand and sixty one thousand years ago. Importantly, in order
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to chow down on humans, mosquitos need to know how
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to find them. They liked evolved genetic encoder receptors for
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detecting hominin body odor slowly over time. For this to happen, however,
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the Sundaland region needed a significant homoerectus population about one
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point eight million years ago. In this way, the scientists
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argue that examining mosquito evolution can help fill in the
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gaps on hominin development and migration, particularly in areas like
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Southeast Asia that contained comparatively limited fossil records. Now let's
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go back to BBC science focus. Could there be a
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human bird flu pandemic in twenty twenty six, maybe, say experts.
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When a highly pathogenic strain of bird flu, the H
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five N one, began sweeping across wild birds and poultry
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in twenty twenty, experts were concerned. Five years on, the
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picture has grown darker and stranger than most would have imagined.
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The virus has spilled into mammals at an unprecedented scale,
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devastated wildlife, and in the US, established itself in dairy cattle,
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a species no one expected to be affected. Human cases
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remain rare, but virologists say the trajectory is troubling. The
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date of pache and the future uncertain. Quote It's now
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a global problem, says doctor Ed Hutchinson, professor of molecular
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and cellular virology at the University of Glasgow, quote as
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a disease of wild animals. It's completely out of control.
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It's raging around the world, and there's no feasible containment
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method other than just watching it infect huge populations of animals.
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The current lineage of H five N one emerged in
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Asia in the late nineteen nineties and has since swept
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from continent to continent. Since twenty twenty, a particularly aggressive
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branch of the virus, known to scientists as clayed two
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point three point four point four B, has spread explosively
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through wild birds. More than one hundred eighty million poultry
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have been infected in the US alone. Egg prices of
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sword in the U s government has spent more than
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one one nine billion dollars reimbursing farmers for losses. For now,
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the human toll remains limited. Only seventy one cases have
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been confirmed in the US, resulting in two deaths. Historically,
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H five in one has been far deadlier. Since two
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thousand and three, almost half of all known human infections
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globally have proved fatal. In early twenty twenty four, though,
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the disease achieved something unprecedented. H five one was found
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in US dairy cattle. Since then, over one thousand dairy
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farms across the country have reported outbreaks. Quote this was
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to everyone's astonishment. Hutchinson says, you now have a situation
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where a large proportion of consumer milk in the US
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at any given time contains genetic material from these highly
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pathogenic viruses. Thankfully, pasteurization destroys the virus, but raw milk,
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along with close contact for workers on dairy farms, still
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poses significant risks of infection. That unexpected species jump, along
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with growing evidence of infection in mammals from seals to
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foxes to bears, increases the number of opportunities the virus
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has to change and adapt. Flu viruses are unusually good
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at evolving because their internal genetic instructions or genome is
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seg minted. If two different strains in fact the same
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infect the same host cell, their gene segments can mix
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and match, producing a new hybrid virus. This process, known
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as genome reassortment, has played a key role in sparking
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past pandemics, and many experts are concerned the same could
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happen if a person infected with a human influenza were
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also infected with bird flu. This may, for example, allow
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the virus to gain the ability to transmit effectively in
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humans while maintaining a structure that is alien and undetectable
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to our immune systems. Quote. In a sense, Hutchinson says,
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the question about reassortment is not when is it going
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to happen, but why isn't it happening all the time,
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because there are so many influence of variants out there
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and we don't really know the barriers to it taking off.
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The US today is one of the most active hotspots
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for avian influenza transmission, yet the national response is fragmented.
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Farm biosecurity measures remain the primary line of defense, even
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as evidence grows that the virus may be traveling between
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farms on the wind, a transportation that fences, disinfectant and
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clean boots can't stop. Meanwhile, virologists say monitoring and reporting
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our weakening. US surveillance varies dramatically between states, complicating assessments
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of how widespread H five to one infections really are.
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Doctor Jeremy Rossman, Honorary Senior Lecturer in virology at the
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University of Kent, says effective containment hinges on broad coordinated surveillance.
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This requires extent of surveillance of infection in multiple animal populations,
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as well as monitoring and testing for animal workers. At
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these farms. He says, this can allow for management of
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any infected flocks or herds, rapid identification of human spillover cases,
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and early detection of new mutations in the virus that
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may affect transmissibility. But in the US, Rossman argues that
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isn't happening consistently. Quote. The response is more limited and
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variable from state to state and farm to farm. Without
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strategic and coordinated surveillance and containment, the risks of a
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human transmissible H five N one virus will steadily rise,
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with unknown but potentially critical consequences, he says. Hutchinson shares
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this concern. Not only are human and animal infections rising,
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he says, but data sharing has become patchier and harder
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to interpret, raising the risk that are warning signs could
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be missed. The good news is that effective vaccines already
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exist to protect both humans and animals, and the US
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is thought to have millions of doses stocked piled. How
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successful is vaccination France adopted poultry vaccination in twenty twenty
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three and saw outbreaks fall by ninety six percent in
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two years, which is impressive, but progress elsewhere has been slow.
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In the US, poultry producers and lawmakers have opposed vaccination
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on trade grounds, warning that it could harm export markets
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and cost the chicken industry ten billion dollars if other
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countries ban US meat. That is despite the outbreak having
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already cost the country billions of dollars, especially ordinary people
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who have seen their grocery bills rise as egg prices
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soared three hundred percent in two years. So how worried
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should we be? The central fear is human to human transmission.
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So far, it hasn't happened in any sustained way, but
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influenza evolves fast, and every new infected host is another
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roll of the genetic dice. Rossmann warns that high levels
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of circulation across species increase the odds of the virus
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evolving into a strain that has both transmissibility and lethality.
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Given the catastrophic implications if it did, tracking and mitigating
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the spread of the H five N one viruses of
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critical importance, there are reasons for optimism. Vaccines and anti
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virals should be effective against avian influenza, and the world
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is far better prepared thanks to lessons learned from the
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COVID nineteen pandemic, particularly in diagnostics in global surveillance, but
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there are caveats too. Scaling vaccines to a global population
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would take time. Anti viral resistance is all already appeared
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in poultry in Canada, and our general immunity to H
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one and H three seasonal flu offers little protection against
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H five strains. Perhaps the sharpest warning comes from computer
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modeling of an outbreak. A twenty five study from Indian
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researchers found that once a pandemic strain began spreading in humans,
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the window for effective containment could be just two to
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ten detected cases. Beyond that, containment would become almost impossible.
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As twenty twenty six begins, H five N one is
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circulating in more species across more continents than ever before.
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Its entrenched in global wildlife. It is destabilized, farming, its mutating, spreading,
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and defying prediction. Hutchinson's message is clear, vigilance not panic. Quote.
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There are reasons to hope as well as reasons to
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be alarmed, he says, but there's death no reason to
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be relaxed about this one. What scientists want next is simple,
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more surveillance, more transparency, more vaccination, and more urgency, especially
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in the US where the virus is spreading rapidly, and
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surveillance remains uneven. Whether they'll get their wishes, however, remains
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to be seen. Now for popular science, dogs act like
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toddlers when trying to help humans. It may be a cliche,
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but it's undeniable. More often than not, cats are simply
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more aloof than dogs. New research suggests the disparities go
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even further, however. According to a study recently published, canine
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companions not only attempt to help humans in certain situations,
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and their actions largely mirror the same responses seen in toddlers. Specifically,
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psychologists in Hungary were interested in comparing the capacity for
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pro social behaveavior across humans, cats, and dogs. Unlike other
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forms of more self interested interactions, pro social tendencies arise
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when an animal or human participates in a way that
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benefits others without the expectation of direct reward or compensation.
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The scientists were surprised to find that over seventy five
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percent of both children and dogs responded similarly in the
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same scenario. This suggests a strong motivation to help despite
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being untrained, receiving no award reward, and the hidden object
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being irrelevant to them. Well, that's all for today's Diary
27:48
of Science and Nature. Your reader was Kelly Taylor. Now
27:51
stay tuned for further programming on RADIOI