Dateline: United Kingdom, Belgium, Washington, and California. Chris, Nevena, Tom, and JD bring you the latest science and discussion from around the world. Seriously, how cool is that?
On This Week’s Show
- Old rocks
- Old fungi
- Tiny fish
- Internet satellites
- The Climate Lounge
- Pub Quiz
Science News with Chris MacAlister, and Nevena Hristozova
Organic matter from space preserved in 3.3 billion year old rocks
- The mountains of South Africa and Swaziland contain 3.3 billion year old volcanic rock which contains carbon filled layers.
- Geologists from France & Italy have been examining these layers and were surprised to find a thin layer where the profile of the carbon was consistent with an extraterrestrial origin.
- Whilst finding extraterrestrial organic matter is not unprecedented, to detect it 3.3 billion years later means that there must have been a lot of it there in the first place.
- If this can happen on Earth then it can happen elsewhere. So if we find it, will we know if it is native to the planet or an offworld contaminant?
Oldest fungi fossils may tell story of how life arrived on land
- The oldest fossils of fungi known until recently were dated to be about 400 million years old and were found in Scotland in the beginning of the 20th century
- With the help of genetic sequencing and comparative genetics between modern existing fungal species though, researchers now estimate that the oldest common ancestor of the modern fungi should be at least 600 million years older than the fungi from those Scottish fossils
- In the meantime, scientists on an expedition at the Canadian Arctic found microscopic imprints embedded in stone, which seem to be fungal fossils too
- Dr. Rainbird (the arctic scientist who collected the fossils) sent the material to Emmanuelle Javaux, a paleontologist at the University of Liège in Belgium to study them
- In another sample, which the teams studied with electron microscope and infrared imaging, they saw two properties very much telling of an ancient fungal species: 1st – a double cell wall (which could hint to fungi or plant cells) and 2nd – a chemical signature of the cell wall indicating the presence of chitin – a sugar which is found only in the cell walls of fungi and not plants
- Even cooler is the fact that these might be the first land fungi out of the ancient oceans. Why? Cause fungi feed by decomposing matter outside their cells by secreting enzymes and then internalising the nutrients. However – if those fossils are of fungi, there weren’t land plants that early in prehistory to feed on, which means that it might have not been plants that first colonised land, but fungi (for the record some fungi can in fact feed on inorganic matter too, which would help if on the land there wasn’t anything organic to munch on yet when those guys decided to live outside the oceans).
The tiniest fish are the most important for healthy coral reefs
- Coral reefs take up 0.1% of the marine environment but house 25% of all marine species despite lacking a clear source of nutrition to support them all. But we may now have an answer.
- Cryptobenthic reef fishes: gobies, blennies,cardinalfishes the smallest of all marine vertebrates.
- These fish breed fast and plentifully, which is just as well as they appear to making up 60% of the fish food in coral reefs.
- How do you calculate the biomass of numerous small fish who like to hide? You sink nets that scare off big fish, pump in anesthetic and count the floaters!
- Cryptobenthic fish larvae don’t disperse into the open ocean like most other larvae.Instead, it’s been found that these larvae stay close to their parents' reefs, yielding many more survivors among their babies. These larvae then replace their rapidly ravaged elders, sustaining the growth of larger reef fishes.
SpaceX launches 60 internet satellites
- The heaviest payload yet to be delivered into earth orbit by the F9 rockets – 60 comms satellites.
- These satellites move in relation to the surface of the Earth and by creating a tight network above it, will make broadband internet coverage a thing for everyone on the surface of the planet.
- The satellites are designed so that once they are about to be decommissioned, they will deorbit.
- They are made of materials which will disintegrate once the satellite re-enters earth's atmosphere.
- This was the third time this 1st stage of the F9 rocket was recovered.
- The potential benefit of such satellites compared to the existing geo-stationary ones is that they are much lower in earth orbit so the signal to earth surface will have to travel much much shorter distance, hence the lag of the internet connection will be much decreased.
- We will need many more than the 60 satellites in low earth orbit for even a minor broadband coverage, but at least the success of this mission is already a darn good start.
The Climate Lounge
Listening to experts on Sea Level Rise
Tom Di Liberto
What do you do when you need an opinion on whether to buy something, or vote a certain way, or just what to believe? Who do you go to? If you said the fever swamps of social media such as Facebook/Twitter, well you might just be the crazy uncle/aunt in your family, and you just described why things have gotten all anti-intellectual across the globe recently.
No, I was looking for something along the lines of “I look for expert opinion”. If I wanted advice on the best layout on a sandwich, I wouldn’t go ask someone who works at an ice cream shop, I’m headed to those sandwich artists at Subway. You get the idea.
In climate science, often those expert opinions can be found summarized in one of a number of massive collaborative consensus reports. The IPCC report is an example and more recently and here in the US, the National Climate Assessment is another. But those reports can be massive and even too conservative (small c, not large C) at times when it comes to certain projections. And today in the lounge, I’m going to talk about just one of those projections, sea level rise.
Sea level rise projections are hard to make confident because of the uncertainties that lie in how fast the ice sheets will melt. Because of this broad uncertainty, the IPCC report is generally conservative with its estimates of global sea level rise.
However in a new article published in the proceedings of the National Academy of Sciences. Scientists asked 22 climate experts to predict ice sheets affect on sea level rise under two scenarios: global temp rise of 2C and 5C (which is unchecked ghg emission growth or business as usual.
Using this technique of expert opinion, the paper reported that sea level rise could plausibly exceed 2 meets (7.5 feet) by 2100 1.78 of which is from melting ice sheets, more than twice as high as the upper limit in the IPCC report. This would displace oh, 187 million people, flood cities like New York, New Orleans, Miami, Shanghai, and Mumbai, wipe island nations off the map. It’s grim folks. REALLLY GRIM.
And the most nonchalant quote on this comes from co-author of the paper Jonathan Bamber at the University of Bristol, who told NBC news that “Two meters is not a good scenario”. You don’t say Jonathan…
And if ghg continued unchecked to 2200 (which let’s be real, they won’t if the impacts are THAT severe) sea levels would rise to 7.5 meters or 24 feet. I say this not to scare but to put into context what sea levels are like when co2 levels get so high
In the 2C scenario, ice sheets would rise 0.8 meters or 2.5 feet. Which is much better than 2 meters but also,…not good.
The key thing here is that a 2 meter sea level rise, while not likely, is plausible, which means that coastal communities have to prepare for that scenario. This paper helps decision makers by highlighting the potential high end estimates of SLR
The novel aspect of this paper is how they came to their conclusions (ok, well yeah, that’s obvious). In particular, ice sheet modeling is a very difficult task which leads to highly uncertain estimates of sea level rise. Recent research has even suggested the behavior of the ice sheets in greenland and antarctic are more uncertain. So instead of relying on mathematical modeling, they looked at the thoughts of 22 climate experts.
Using a standardized interview technique called structured expert judgement, they asked the experts to predict the ice sheets affect in the two scenarios I mentioned before. The Structured expert judgment technique allowed the scientists to give their scientific rationales for their uncertainty judgements related to sea ice contribution and even helped highlight poorly understood but potentially critical processes related to ice sheet melting.
So I guess what I’m trying to tell all of you is that, asking experts for their thoughts can be a really important thing when you have to plan for the negative outcomes related to those experts lines of work. Who’d a thunk it.
That concludes this episode of the Blue Streak Science Podcast.
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This show is produced by the Blue Streak Science team, and edited by Pro Podcast Solutions.
Our hosts today were Chris MacAlister, Nevena Hristozova, and Tom Di Liberto.
I’m JD Goodwin.
Thank you for joining us.
And remember…follow the science!