Lethal Underwater Briny Icicle

BBC has some phenomenal footage of an icicle forming from salty water in the Antarctic. It crawls down into the water (because the density of the saltwater makes it sink) and freezes everything around it, including the poor animals underneath.

That video was not posted by the BBC so hopefully it doesn’t get taken down too soon. Here’s the camera set-up they used:

I don't think my camera can do that

You should check out their article for the description of the brinicle. Very cool stuff. It feels like nature is just always up to random amazing things without us ever realizing it. 

Explaining the Earth’s Liquid Outer Core

Weekends are lean times here at Science Picks; I see a few dozen new articles a day as opposed to the ~500 new articles per weekday that I get to choose from. Fortunately, some articles/blog posts aren’t news but are just interesting reviews of some aspects of science, so they’re good for whenever I want to share them. So from my bag of saved articles, I bring you:

Why does the Earth have a liquid core? from Starts With a Bang. I really enjoy Starts With a Bang, and I think you should definitely check out other posts from there if Ethan’s style is appealing to you. Also, check out the comments on his blog posts, since his readers have pretty interesting questions and comments as well. Enjoy!

The Possible Birthplace of Life on Earth

I wanted my 100th post on this blog to be about something suitably epic; this article should do. It’s about the identification of a group of volcanoes in Greenland that may have had the right conditions for creating life 3.8 billion years ago, something that hasn’t been found anywhere else. 

From Science Daily:

The mud volcanoes at Isua, in south-west Greenland, have been identified as a possible birthplace for life on Earth by an international team headed by researchers from the Laboratoire de Géologie de Lyon: Terre, Planètes et Environnement (CNRS/Université Claude Bernard Lyon 1/ENS de Lyon). Almost four billion years ago, these volcanoes released chemical elements indispensable to the formation of the first biomolecules, under conditions favorable to life. It is the first time that such an environment, meeting all the requirements for the emergence of life, has been identified by scientists in 3.8 billion year-old formations…

Mud volcanoes are cooler than igneous volcanoes, and don’t eject lava. According to Wikipedia, “Ejected materials are often a slurry of fine solids suspended in liquids which may include water, which is frequently acidic or salty, and hydrocarbon fluids.” Sounds nasty. 

Serpentinite is a dark green mineral used in decoration and jewelry. In nature, it is formed when sea water infiltrates into Earth’s upper mantle, at depths that can reach 200 km in subduction zones. According to the scientists, this mineral, often found in the walls of hydrothermal sources, could play a major role in the appearance of the first biomolecules…

The team of scientists publishing this article focused their studies on serpentinites from Isua, in south-west Greenland, which date from the start of the Archean [4 to 2.5 billion years ago]. Dating back some 3.8 billion years, the rocks of Isua are some of the oldest in the world. Using isotopes of zinc as indicators of the basic or acid nature of an environment, the researchers highlighted the basic character of the thermal fluids that permeated the Isua serpentinites, thus demonstrating that these minerals formed a favorable environment for amino-acid stabilization…

Nearly four billion years ago, at a time when the continents only occupied a very small part of the surface area of the globe, the oceanic crust of Isua was permeated by basic hydrothermal fluids, rich in carbonates, and at temperatures ranging from 100 to 300°C. Phosphorus, another indispensable element to life, is abundant in environments where serpentinization takes place. As this process generates mud volcanoes, all the necessary conditions were gathered at Isua for organic molecules to form and be stable. The mud volcanoes at Isua thus represent a particularly favorable setting for the emergence of primitive terrestrial life.

So that’s pretty cool. However, as fun as it may be to point at a specific place as the origin of life, we have to of course keep in mind that this is just one possibility. Life is generally thought to have originated near hydrothermal vents, so those are still a possibility. It’s also hard or impossible to say that this location at Isua is more likely than others, since, as they say, those are some of the oldest rocks in the world; there’s no way to compare them to equally old rocks everywhere else.

Could still make for a good tourist attraction though…

What We Do and Don’t Know About Climate Change

As I said in the last post, the science behind climate change has been in the news recently, which brings the side benefit of having New Scientist publish a series of articles on climate change for our education. You may not be able to access the articles without registering with them (for free), but they’re very short in any case and I’ll summarize them here. Because they’re very short though, be warned that they’re probably slight-to-gross oversimplifications, so don’t take any of this as whole, perfect truths. 

This ended up being super duper long – feel free to just skim over the titles and read more only if you’re interested. I think the important thing to note is that we don’t know everything – and we likely never will. That applies to every field of science though, as the final article eloquently explains. Climate change science has been brutally politicized, but that shouldn’t distract people from the facts.

Climate known: Greenhouse gasses are warming the planet

From melting glaciers and earlier springs to advancing treelines and changing animal ranges, many lines of evidence back up what thermometers tell us – Earth is getting warmer. Over the 20th century, the average global temperature rose by 0.8 °C

Studies of Earth’s past climate tell us that whenever CO2 levels have risen, the planet has warmed. Since the beginning of the industrial age in the 19th century, CO2 levels in the atmosphere have increased from 280 parts per million to 380 ppm. Satellite measurements now show both that less infrared of the specific frequencies absorbed by CO2 and other greenhouses gases is escaping the planet and that more infrared of the same frequencies is being reflected back to Earth’s surface. While many factors affect our planet’s climate, there is overwhelming evidence that CO2 is the prime cause of its recent warming.

Climate unknown: How much greenhouse gas to expect

The biggest uncertainty is human… Our current emissions trajectory is close to the worst-case scenario of the Intergovernmental Panel on Climate Change (IPCC). If we continue on this path, CO2 levels could hit 1000 ppmby 2100 – or perhaps even higher.

The second uncertainty is Earth’s response… Currently, rising CO2 levels are driving global warming, but in the past CO2 levels have naturally risen in response to rising temperatures. We do not know why exactly, but the reduced solubility of CO2 in warm water and changes in biological activity have been suggested as reasons. If such mechanisms kick in, even bigger cuts in emissions will be needed to limit warming.

There are also vast quantities of greenhouse gases locked away in permafrost, in peat bogs and undersea methane hydrate deposits. We don’t know how big these stores are. Nor do we know how much permafrost will melt, or how much peat will dry out and decay, or whether the seas will get warm enough to trigger the release of methane – an even more potent greenhouse gas than CO2 – from the hydrates.

Climate known: Other pollutants are cooling the planet

We pump all kinds of substances into the atmosphere. Nitrous oxide and CFCs warm the planet as CO2 does. Black carbon – soot – warms things up overall by soaking up heat, but cools Earth’s surface by shading it. But other pollutants reflect the sun’s heat back into space and so cool things down…

Burning sulphurous fossil fuels has been adding huge amounts of SO2 to the atmosphere. Between the 1940s and 1970s, this pollution was so high that it balanced out warming from CO2. But as western countries limited sulphur emissions to tackle acid rain, the masking effect was lost and global warming resumed.

Sulphur emissions began rising again in 2000, largely as China built more coal-fired power stations. Now China is installing sulphur-scrubbing equipmentin those power stations. If SO2 emissions fall, global warming could accelerate…

Climate unknown: How great our cooling effects are

Pollutants that form minute aerosol droplets in the atmosphere have horrendously complex effects. How much radiation is reflected by sulphur dioxide aerosols varies according to the size of the droplets, their height in the atmosphere, whether it is night or day, what season it is and several other factors…

But if aerosol cooling is larger than generally assumed, the planet will warm more rapidly than predicted as soon as aerosol levels fall.

Climate known: The planet is going to get a lot hotter

Take water. Water vapour is a powerful greenhouse gas. When an atmosphere warms, it holds more of the stuff. As soon as more CO2 enters a watery planet’s atmosphere, its warming effect is rapidly amplified.

This is not the only such “positive feedback” effect. Any warming also leads to the rapid loss of snow cover and sea ice, both of which reflect sunlight back into space. The result is that more heat is absorbed and warming escalates. Longer timescales bring changes in vegetation that also affect heat absorption, and the possibility that land and oceans begin to release CO2 rather than absorb it. Over hundreds or thousands of years, vast ice sheets can melt away, further decreasing the planet’s reflectivity. Barring some unexpected catastrophe such as a megavolcano eruption, then, the planet is going to warm considerably.

Climate unknown: Just how much hotter things will get

The bulk of the evidence still points to a short-term climate sensitivity of around 3 °C, as the IPCC’s models suggest. But while a figure much lower than that is unlikely, there is a significant probability of higher sensitivities (see diagram)…

Climate unknown: How things will change in each region

Even with an average global temperature rise of just 2 °C, there will be some pretty dramatic changes. Which regions are going to turn into tropical paradises? Which into unbearably humid hellholes? Which into deserts? For planning purposes it would be useful to know.

Unfortunately, we don’t. The broad picture is that the tropics will expand and get a bit wetter. The dry zones either side of the tropics will get dryer and move towards the poles. High latitudes will get much warmer and wetter.

When it comes to the finer details, though, there is not much agreement…

Climate known: Sea level is going to rise many metres

Studies of sea level and temperatures over the past million years suggest that each 1°C rise in the global mean temperature eventually leads to a 20-metre rise in sea level.

That makes the effects of a rise of at least 2°C rather alarming. How alarming depends on how quickly the great ice sheets melt in response to warming – and that is another big unknown.

Climate unknown: How quickly sea level will rise

We have little clue how much room we have for manoeuvre. Past melting episodes provide little help. Melting can be rapid: as the last ice age ended, the disappearance of the ice sheet covering North America increased sea level by more than a metre per century at times. It is unclear if Greenland’s ice will melt as rapidly.

To predict exactly how quickly sea level will rise, we would first need to know how much hotter the planet is going to get. As we have seen, we don’t.

Climate unknown: How serious the threat to life is

Many species will have to move to stay within a tolerable temperature range. Animals will also have to change their time of hatching or migration to stay in sync with food sources. Many won’t make it: theoretical studies based on relatively conservative warming scenarios have come up with dire estimates of a third or more terrestrial species going extinct. Real-world studies of the effects of warming so far have backed these conclusions.

Climate known: There will be more floods and droughts

Warm air holds more moisture: about 5 per cent more for each 1°C temperature increase. This means more rain or snow overall, and more intense rain or snowfall on average.This trend is already evident, and is stronger than models predict.

More intense precipitation means more floods…

Although most of the world will get more rainfall on average, dry periods will still occur from time to time. When they do, soils will dry out faster because of the higher temperatures. Once soils dry out, the sun’s heat goes into warming the land rather than evaporating water, triggering or exacerbating heatwaves.

Climate unknown: Will there be more hurricanes?

As the lower atmosphere gets warmer and wetter over the coming decades, there will be more fuel available to power extreme storms. But how often will this fuel ignite? Hurricanes are relatively rare because they form only when conditions are just right. While higher sea-surface temperatures will favour their formation, stronger high-level winds may rip them apart. The result could be fewer hurricanes overall, but with greater strength when they do occur. As the destructive power of hurricanes rises exponentially with increasing wind speed, a few intense storms could wreak more havoc than many weak ones.

At temperate northern latitudes, the news might be better. There winter storms are powered largely by the temperature differences between cold air from the poles and warmer air masses from the tropics. Such storms may become less common as rapid warming in the Arctic reduces the temperature differences.

Climate unknown: If and when tipping points will come

If the Arctic suddenly cooled, sea ice would recover within a few years. If the great ice sheets of Greenland and Antarctica lose enough ice to raise sea level a metre or more, though, it would take thousands of years for snowfall to build up the ice sheets again. The risk is real: we know that the West Antarctic ice sheet has collapsed many times in the past, raising sea levels at least 3 metres.

We can identify many other such dangerous “tipping points“. The Amazon could flip from being rainforest to grassland, just as the Sahara suddenly dried up 8000 years ago. Massive amounts of methane could be released from undersea methane hydrates.

I really like the concluding article. Here it is (most of it anyway) in its sciency glory:

The biggest climate change uncertainty of all

WOULD you jump off a skyscraper? What if someone told you that physicists still don’t fully understand gravity: would you risk it then?

We still have a lot to learn about gravity, but that doesn’t make jumping off a skyscraper a good idea. Similarly, we still have a lot to learn about the climate but that doesn’t make pumping ever more greenhouse gases into the atmosphere a good idea.

Uncertainty is one of the defining features of science. Absolute proof exists only in mathematics. In the real world, it is impossible to prove that scientific theories are right in every circumstance; we can only prove that they are wrong. This provisionality can cause people to lose faith in the conclusions of science, but it shouldn’t. The recent history of science is not one of well-established theories being proven wrong. Rather, it is of theories being gradually refined. Newton’s laws of gravity may have been superseded, but they are still accurate enough to be used for many purposes…

In fact, perhaps the biggest source of uncertainty is not to do with the science at all, or the global climate system, but with us.

Will we burn every last drop of fossil fuel? Or will some amazing technological advance make the switch to renewable energy a no-brainer? Will we keep building cities in places vulnerable to sea-level rise, like Shanghai?

Even politicians who back action to curb global warming are not delivering on their promises. Many of the countries that signed up to the Kyoto protocol have failed to achieve their very modest targets. Meanwhile, some countries in Europe are signing up to more ambitious goals for reducing emissions by 2030, while still commissioning coal-fired power stations.

By the time the need for drastic action becomes blindingly obvious, the best opportunity to curb harmful change will have been squandered. Yet if draconian action is taken today, any success in limiting warming will be greeted with scepticism that drastic measures were ever worthwhile or even necessary. Perhaps the greatest unknown, then, is how to persuade people to act today to help protect their long-term future, not to mention future generations.

One more thing is certain: only science can reveal how our planet can provide a decent home for billions of people without toppling over the precipice.

I love it. Succinct, honest and forthright. 

Climate Change Science In the News Again

The science behind climate change has been thrust back into the media spotlight in the last few days, after a former global warming skeptic and Berkeley physicist led a study that ended up corroborating prior research showing that the Earth is indeed warming. He wrote an op-ed for the Wall Street Journal explaining why he had been skeptical of the climate change evidence and how his own study took into account all of the factors that had left him doubtful, and ended up agreeing with the mainstream evidence after all. 

If you’ve heard scientific-sounding arguments against climate change and weren’t sure how to address them, this op-ed might be interesting to you. The punchline, though, is this:

When we began our study, we felt that skeptics had raised legitimate issues, and we didn’t know what we’d find. Our results turned out to be close to those published by prior groups. We think that means that those groups had truly been very careful in their work, despite their inability to convince some skeptics of that. They managed to avoid bias in their data selection, homogenization and other corrections.

Global warming is real. Perhaps our results will help cool this portion of the climate debate. How much of the warming is due to humans and what will be the likely effects? We made no independent assessment of that.

On its surface this news story sounds like a good thing, but I don’t like it. The soundbite version is that “even a skeptical scientist was convinced once he looked hard at the evidence.” The implication is that the vast majority of scientists who accept climate change theory aren’t sufficiently, reasonably skeptical. It promotes the idea that mainstream scientists can’t be trusted, which is why an “outsider”, a member of the denial faction, had to find out for himself and carry the word back to his fellow deniers. 

Obviously that’s only my very subjective take on things, but I can’t help but feel that that’s how news agencies are pitching it to the public. Otherwise, it would be irrelevant that this physicist was a climate change skeptic – it has no bearing on the science, it’s purely a means of making him sound trustworthy to other deniers. It may serve to convert some people, but for a lot of people it’ll only reinforce their “scientists can’t be trusted” mentality – and now this physicist will be just one of those lying mainstream scientists to them. 

That being said, what’s the alternative way of convincing deniers? I don’t know… I’d like to go on about this, but since this is Science Picks and not André Rants I’ll move on: I want to share an interesting series of articles from New Scientist discussing what we do and don’t know about climate change. I don’t want this post to be crazy long, so check it out in the next post!

The Aftermath of a Magnitude 9.0 Earthquake

The massive earthquake that hit Japan in March – one of the five strongest recorded earthquakes ever – has been out of the headlines for a while now; there are still stories about the effect on nuclear power policy, but I personally haven’t seen much else. It turns out that scientists are hard at work tracking the debris from the earthquake as anything from Japanese boats to home appliances drift slowly across the ocean. Debris is expected to reach Hawaii in 2 years and the west coast of North America in 3 years. I imagine sitting on a beach in California and seeing a TV wash up on the shore would be a pretty powerful connection to the disaster on the other side of the world. 

From Scientific American:

Debris from the devastating tsunami that hit Japan on March 11 has turned up exactly where scientists predicted it would after months of floating across the Pacific Ocean. Finding and confirming where the debris ended up gives them a better idea of where it’s headed next.

The magnitude 9.0 quake and ensuing tsunami that struck off the coast of Tohoku in Japan was so powerful that it broke off huge icebergs thousands of miles away in the Antarctic, locally altered Earth’s gravity field, and washed millions of tons of debris into the Pacific.

Scientists at the International Pacific Research Center at the University of Hawaii at Manoa have been trying to track the trajectory of this debris, which can threaten small ships and coastlines. The new sightings should help the scientists predict when the debris, which ranges from pieces of fishing vessels to TV sets, will arrive at sensitive locations, such as marine reserves…

Warned by maps of the scientists’ model, a Russian ship, the STS Pallada, found an array of unmistakable tsunami debris on its homeward voyage from Honolulu to Vladivostok.

Soon after passing Midway Islands, crew members aboard the Pallada spotted a surprising number of floating items.

“Yesterday, i.e. on September 22, in position 31 [degrees] 42,21 N and 174 [degrees] 45,21 E, we picked up on board the Japanese fishing boat. Radioactivity level — normal, we’ve measured it with the Geiger counter,” wrote Natalia Borodina, information and education mate of the Pallada. “At the approaches to the mentioned position (maybe 10 – 15 minutes before) we also sighted a TV set, fridge and a couple of other home appliances.”

Later, on Sept. 27, she wrote: “We keep sighting every day things like wooden boards, plastic bottles, buoys from fishing nets (small and big ones), an object resembling wash basin, drums, boots, other wastes. All these objects are floating by the ship.”

… The most remarkable piece of debris is of a small fishing vessel about 20 feet (6 meters) long, which they were able to hoist up onto the Pallada. The markings on the wheelhouse of the boat show its homeport to be in the Fukushima Prefecture, the area hardest hit by the massive tsunami.

I never really thought about this aftereffect of a tsunami. It’s pretty devastating… I’m glad Canada is boring. 

A New Source of Lithium For Batteries: Geothermal Power Plants

From Scientific American: In a double-dose of environmental goodness, a new technology allows lithium (the key component of lithium-ion batteries that power portable electronics and most electric cars) to be collected as a byproduct of geothermal power production.

Geothermal electricity is generated by pumping up hot water from deep underground and using the heat to make gas turn turbines and power a generator. This can be done by a) pumping up steam in the first place, and making that turn the turbines, b) pumping up hot, high-pressure water and then turning it into steam by decreasing its pressure, or c) pumping up hot water and transferring its heat to another fluid with a lower boiling point, like butane or pentane, turning those into gas. This last solution means that the water doesn’t have to be quite as hot to get the job done.

In any of these cases, the used water is then pumped back down to the source, maintaining the underground reservoir. The new development in question, from Lawrence Livermore National Laboratory, adds an extra step: before injecting the water back underground, they use a novel extraction process to remove its lithium content. This water (or brine, meaning it carries dissolved salts) has had a long time to dissolve the minerals around it underground, making it a rich source of seemingly everything:

The Salton Sea brine contains a host of other elements, and Simbol hopes to extend the extraction process to manganese and zinc—also used in batteries and metal alloys—as well as potassium, which is a vital nutrient and fertilizer, among other applications. “This brine has got half the periodic table in it and that’s a good news–bad news situation,” Erceg says, noting that cesium, rubidium and silver might also be produced the same way. The company is also exploring options for using the process’s waste silica—more commonly known as sand—in the cement industry.

This is clearly a step up from lithium mining; extracting lithium from a renewable, constant source that’s brought right to you. If this new technology simultaneously encourages the development of alternative energy and feasible electric cars, I’ll consider it a big win all-around.

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