Archive for the 'General Science' Category

Jan 24 2023

Bacteria That Eat Plastic

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The world produces about 380 million tons of plastic every year, and half of that is single use plastic. This figure is projected to increase by 70% by 2050. A 2017 study found that of all the plastic produced, “9% of which had been recycled, 12% was incinerated, and 79% was accumulated in landfills or the natural environment.” Current practices are unsustainable, as a lot of this plastic ends up in the oceans and elsewhere in the environment. Researchers are increasing looking to bacteria as one potential solution to this problem.

Recycling alone is not a viable solution. Currently, the main effect of recycling plastic is to create a false sense that the problem is being addressed. Plastic is not really recycled in a full circular process. A relatively small portion of plastic is broken down and then remanufactured into lower quality plastics that cannot be recycled. The ultimate fate of all plastics is still the incinerator (not good for the environment), landfills, or the oceans and other environmental locations. What are the potential solutions to this situation?

One solution is to use less plastic. But this is a complex suggestion. Single use plastic is the most common target, and there is a lot of wasteful use that certainly can be reduced. But half of plastic produced is not single use, and a lot of plastic is necessary for certain applications (such as sterile medical use). As always, you also have to consider the alternatives – what will replace this plastic? Sometimes there is an obvious and good solution. In many beverage applications, aluminum can replace plastic and is more recyclable.  Glass is another alternative material. But this approach will only get us so far.

Part of the problem is that plastic is cheap to mass produce, and it works very well for the intended applications. It’s cheaper to make virgin plastic than to recycle old plastic. This reality feeds the problem.

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Jan 03 2023

2015 to 2022 Eight Warmest Years on Record

Happy New Year to all my readers.

Early in each new year I like to see what the preliminary reports are for the climate over the past year. Final number crunching won’t be available for months, and it may take more than a year for the final tweaks to be reported and reviewed. But we do have a preliminary estimate of the temperature over the last year. The World Meteorological Organization reports:

The global average temperature in 2022 is estimated to be about 1.15 [1.02 to 1.28] °C above the 1850-1900 average. 2015 to 2022 are likely to be the eight warmest years on record. La Niña conditions have dominated since late 2020 and are expected to continue until the end of 2022. Continuing La Niña has kept global temperatures relatively «low» for the past two years – albeit higher than the last significant La Niña in 2011.

It looks like 2022 will be the fourth hottest year on record globally. Some specific locations had their warmest year, such as the UK and Spain (and perhaps most of Europe). As the WMO points out, we are in the middle of a La Niña cycle, which brings cooler temperatures globally. That is a short term fluctuation on the longer term trend. This also means that as we shift into an El Niño cycle we are likely to break new records.

I feel compelled to point all this out (as I am sure many scientists and science communicator will) because it is a critically important piece of information. But I also want to put it into a broader long term context. I have been engaged in skeptical activism now for 27 years, and followed many skeptical topics for longer than that. There is one extremely important pattern that emerges when you cover a topic for a long time – scientifically valid concepts tend to not only accumulate evidence but the evidence gets better and builds on itself. Meanwhile, pseudosciences do not display this pattern. They tend to go around in circles with low quality evidence. You can see this pattern across multiple disciplines.

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Dec 20 2022

Best Science News 2022

It’s always fun and interesting to look back at the science news of the previous year, mainly because of how much of it I have forgotten. What makes a science news item noteworthy? Ultimately it’s fairly subjective, and we don’t yet have enough time to really see what the long term impact of any particular discovery or incremental advance was. So I am not going to give any ranked list, just reminisce about some of the cool science and technology new from the past year, in no particular order. I encourage you to extend the discussion to the comments – let me know what you though had or will have the most impact from the past year.

Fusion

I have to start with the fusion breakthrough, mainly because it is the most recent in my memory and I suspect it will top a lot of lists. The National Ignition Facility managed to achieve what they call “ignition” by producing fusion that created more energy than the energy put into the fuel. This is clearly a milestone. However, this particular setup, referred to as inertial confinement, which uses 192 high power lasers to implode a container which has the fuel, is likely a dead end when it comes to commercial energy production. It was never really designed to be that, just an experiment in fusion. I doubt this will be the method we ultimately use for commercial fusion, which I also predict is still many decades away. We will see in a generation how this news is looked back upon, if at all.

Space

This was a good year for space exploration. The successful launch of Artemis I marks the beginning of our return to the moon. The SLS rocket worked, and it’s more powerful than even the Atlas V. It carried the Orion capsule past the moon and back again, successfully returning to the Earth. Returning to the moon now seems inevitable. Artemis II will launch in 2024 and carry people to the moon but not land. Artemis III will land people on the moon, in 2025 or 2026. It’s going to be exciting to watch.

The other big space news, of course, was the James Webb space telescope (JWST), which is already sending back mind-blowing pictures of the universe. We are just at the beginning of its career, which will likely last 20 years. Can’t wait to see what else it sends us.

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Nov 18 2022

The Potential of Geothermal Energy

Published by under General Science

As we discuss the optimal path forward for the next 30 years to get to net-zero carbon emissions for the energy sector, one big variable is the real-world potential of geothermal energy. Right now in the US geothermal produces 0.4% of our electricity. That is almost negligible, and is not going to help get us to our goal without an order of magnitude or more increase. What is the probability that we can bring significant geothermal online within 20-30 years?

Producing electricity at large scale is mostly about turning turbines, which rotates a magnet within a coil of conducting cable which generates electrical current in the wires. Turbines are turned by two basic methods – mechanical or with steam which in turn is generated by some heat source. Hydroelectric and wind turbines rotate the turbines through mechanical power. Burning fossil fuel or nuclear power plants produce heat to create steam. Solar photovoltaics are the exception because they directly turn sunlight into electricity through the photoelectric effect. But direct solar capture can use sunlight to once again heat a target, create steam, and turn a turbine.

Geothermal energy uses steam created by the natural heat below the surface of the earth to turn a turbine to make electricity. In a recent TEDx talk, Matt Houde who is the cofounder of a geothermal energy company points out that there is enough heat in the ground to power our world for a billion years. It’s a practically unlimited energy source. Why isn’t that, then, problem solved – all the energy we can need for the foreseeable future (arguably longer than human civilization is likely to last on earth) is right beneath our feet? The problem is – that heat is hard to get to.

From my reading it seems that there are three types of geothermal energy depending on our ability to access the heat. Current geothermal, the kind making up that 0.4%, takes advantage of natural hot spring that reach near or at the surface. Boise Idaho, for example, directly heats building from natural hot springs. You can also use near surface heated water to create electrical power. This was the low-hanging fruit of geothermal, but if we want an order of magnitude increase we need to develop what is called advanced geothermal. This approach uses technology developed by the fracking industry to drill down to the heat, inject water if necessary (if water is not already present), and then use that heated water to drive turbines.

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Nov 15 2022

Cache of Ancient Bronze Statues Found

Published by under General Science

Archaeologists have uncovered a large cache of over 50 small bronze statues in the ruins of an ancient temple in Tuscany. The find dates from the second century BCE to the first century ACE. It is being reported as the greatest bronze statue find in 50 years, one of the greatest finds ever, and a significant window into that period of history.

The statues themselves range from small representations of specific body parts, to statues representing the gods and up to a meter in length. These statues were deliberately tossed into a thermal spring within the temple, where they sunk to the bottom and were covered in mud. The mud preserved the statues in relatively good condition for the last two thousand years. Many of the statues also have writing on them, in either Roman or Etruscan. Archaeologists believe that these statues were offerings to the gods intended for healings. The body parts represent the ailment that the offerer wishes to be healed. They also found over 5,000 gold, silver, and bronze coins that were tossed into the spring over those three centuries.

Essentially, this thermal spring and temple were the equivalent of a spa for the wealthy. Bathing in hot springs was a common luxury for the wealthy of the time, and this temple was also clearly not a public place. Rather, this was likely a private location for the wealthy and elite. The bronze statues would have been very expensive, only affordable just to be tossed into the waters by the very wealthy.

It’s easy to become smug from our modern perspective about the primitive behavior of making offerings to imaginary gods in hopes of being healed. But I think the opposite reaction is more appropriate. Certainly making such offerings in the genuine hope of being healed is pure superstition, and also completely useless in terms of effecting real change to one’s health. Given the primitive state of medicine at the time, however, it was also pretty harmless (and an archaeological boon, it turns out). Even the wealthy and powerful did not have access to what we could consider basic health care, and so tossing expensive bronze statues was the best they had.

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Nov 14 2022

The Lies of Climate Change Denial

Published by under General Science

Whenever I write about climate change here, the deniers show up spouting dubious (to say the least) claims. In my opinion, this is a manifestation of a deliberate political strategy, one that we see with other topics. The strategy is to make up blatant lies, or at least claims without the slightest regard for whether or not they are true, and then spread them through ideologically friendly outlets. Sometimes this may involve amplifying claims that emerge from the most extreme “fever swamps” promoting that ideology. Just keep throwing crap against the wall, and some of it will stick. When these notions make their way into the mainstream media, they are quickly debunked. But by then it’s too late – the damage is done. Long after the false claims are soundly refuted, the rank and file believers will still be quoting them. They are now part of the narrative.

This means that for science communicators and skeptics (but also mainstream journalists), we need to have a working knowledge of these common false claims that are circulating, so that we can respond to them quickly when they emerge. One of the reasons I allow such comments to continue in my blog is because that is one of the ways that I can see which claims are circulating. I don’t mind if they come here – we can handle it. Normally I handle the claims in the comments, but occasionally there is a critical mass of nonsense that is more efficiently dealt with by a post. Here are some recent claims.

Volcanoes emit more greenhouse gas than human activity.

This is an old one, but has remarkable persistence. These claims go through a selection process. Claims survive not because they are true, but because they resonate. In this case, the volcano claim fits the overall narrative that meager human activity is nothing compared to the awesome scale of nature. They want to portray the very idea that we can alter the climate as ridiculous.  Fact, however, get in the way of this narrative.

According to the US Geological Survey:

Published scientific estimates of the global CO2 emission rate for all degassing subaerial (on land) and submarine volcanoes lie in a range from 0.13 gigaton to 0.44 gigaton per year.

That sounds like a lot, but human activity releases 35 gigatons of CO2 each year. That means that human activity releases more than 100 times the CO2 as does all volcanic activity. When I pointed this out in the comments, these easily verifiable scientific facts were dismissed as a liberal conspiracy. Another strategy is to simply shift to another claim, without ever admitting that you were wrong on the first one. In this case just shift over to methane – but that is a loser argument also. Of all the methane released into the atmosphere each year, 60% is due to human causes. All natural sources amount to only 40%, and volcanoes are a minority of that. Most methane on Earth comes from biology.

I do admit it still surprises me when this one is trotted out, because these are easily checkable basic facts. This is a good way to completely squander one’s credibility. I think this says something meaningful about the intellectual process that is being employed by those dedicated to the denial of global warming.

 

Climate models are simplistic and wrong.

Dismissing climate models is a more complex matter to refute, because this is more than just looking up a couple of numbers. First there is the notion that climate scientists, in producing their models which predict anthropogenic global warming, did not consider natural factors. This is, of course, absurd, and represents non-experts criticizing an entire world-wide community of experts from a profound level of relative ignorance – and doing it with confidence and arrogance. This almost always comes without citations, or by citing only known outliers.

Climate models, from the beginning, have sought to include the latest science available and account for all possible factors. Over the last 50 years climate models have been steadily modified, to account for new scientific data as it comes in. In addition, models have to account for future behavior, such as how much CO2 will the world emit in the future. So they can only give ranges of outcomes based upon explicitly stated assumptions about human behavior in the future. Often models are used to project what will happen under various scenarios – continuing our current trends vs changing course.

One of the best ways to determine how well models predict the climate (how “skillful” they are, in the jargon) is to see how past models predicted later climate change. This has been done multiple time. Here is a 2019 review of 17 climate models. They found:

We find that climate models published over the past five decades were skillful in predicting subsequent GMST changes, with most models examined showing warming consistent with observations, particularly when mismatches between model-projected and observationally estimated forcings were taken into account.

That last bit means the difference between projections of CO2 emissions vs actual CO2 emissions. The bottom line is that the model basically work, and they are continuously getting better as they incorporate the latest science. Computers are also getting more powerful, allowing for more complex climate simulations. But still you will frequently hear things like, “Maybe it’s the sun. All those scientists never thought of that.”

A recent commenter brought up one I had not yet heard – neutrinos warming up the inner Earth and all that heat rising to the surface through ocean vents. The commenter also explicitly states that climate models do not include natural sources of warming. Sure, there is geological sources of heat that affect the climate – and climate scientists are well aware of this factor.  Geothermal ocean heating is a known factor. It has a relatively small magnitude, and there is no reason to think that it has suddenly changed in the last 50 years. But the notion that climate scientists are not away of geothermal heating is just silly.

 

CO2 causes greening which absorbs excess CO2.

The basic notion that increases in CO2 concentrations in the atmosphere increases plant growth is true. CO2 is an important metabolite for plant growth. But the full story is more complicated, and turning this into a net benefit from climate change is simply not true. The increase in productivity does occur, but also results in a depletion of other nutrients, such as nitrogen, from the soil. It therefore is not sustainable in natural settings (i.e. not farmland where nutrients can be added). Also, plants are not adapted to higher CO2 levels and so they get diminishing returns from higher CO2.

But the main reason this is not a valid argument against the need to mitigate climate change, is that it ignores all the other effects. Increasing temperature and worsening droughts are bad for agriculture. Shifting climate also shifts growing zones away from where they are currently located. Also, the effect on different crops varies. Wheat will benefit, but corn production will drop, while some other crops will see no immediate change. This will be highly disruptive to agricultural infrastructure. Also, as warming continues, the effects of increased temperature and drought will overwhelm any positive effect from CO2.

The notion that plants will simply absorb any excess CO2 is also profoundly naive and just factually incorrect. There is a carbon cycle, which already includes plants absorbing CO2. But plants don’t just sequester CO2, they absorb and emit CO2 in a continuous cycle. The more CO2 there is in the system, the more CO2 there will be in every part of the system (plants, the ocean, the atmosphere, in minerals, etc.). This is already accounted for in climate models.

But sure, we should maximize biomass to help mitigate CO2 release, and stop doing things like cutting down the rainforest. But this is not going to compensate for the 35 billions tons of CO2 humans release every year.

 

 

 

 

 

 

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Nov 11 2022

COP27 and the State of the Climate

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So how are we doing? We’ve been talking about mitigating climate change for literally decades, and the world is currently meeting for the 27th climate summit, COP27. It feels like all we get is dire news about how miserably we are collectively failing to do anything about climate change, but the real news is actually mixed. In some ways we are better off then we were 1-2 decades ago, in others things are worse. Let’s review.

The good news is that the projection of how much the climate will warm on average is better today than it was a decade ago. Warming is measured as the average temperature increase above pre-industrial levels, usually expressed in Centigrade. Right now we are at 1 degree C above baseline. A decade ago if you looked at projections as to where we were headed, the “business and usual” projections were for 3-4 degrees C by the end of the century. Today, the same projections predict only about 2.4 degrees. Business as usual means that we keep going the way we are, including already funded pledges from countries for action to mitigate CO2 release.

It’s also not hard to do better than 2.4. A recent study published in nature extrapolates climate change for a range of scenarios, starting with what they call nationally determined contributions (NDC), which are essentially pledges as of COP26. This is one step beyond business as usual because it includes all pledges, even those not yet funded. They also consider peak warming and warming by 2100. If we reduce greenhouse gas (GHG) emissions temperature will eventually come down, as the effect of GHGs is not permanent. The NDC scenario has peak warming of about 1.8 degrees, but then coming down to about 1.7.

They also include a range of models, from various degrees of NDC to NDC+ and NDC++, including greater mitigation efforts sooner. In the NDC+ range warming will peak at 1.6 but then come down to 1.4. In the most aggressive scenario, NDC++ we can theoretically limit peak warming to <1.5 C, which is the stated goal of the Paris agreement. This entire range of scenarios, even just the NDC where we keep already made pledges, is not horrible. It keeps peak warming below the 2.0 C level where we think the inflection point is for irreversible (on a human timescale) negative consequences.

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Oct 31 2022

Alternative Gene Splicing – Another Method of Bioengineering

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Genetic engineering is a rapidly progressing scientific discipline, with tremendous current application and future potential. It’s a bit dizzying for a science communicator who is not directly involved in genetics research to keep up. I do have some graduate level training in genetics so at least I understand the language enough to try to translate the latest research for a general audience.

Many readers have by now heard of CRISPR – a powerful method of altering or silencing genes that brings down the cost and complexity so that almost any genetics lab can use this technique. CRISPR is actually just the latest of several powerful gene-altering techniques, such as TALEN. CRISPR is essentially a way to target a specific sequence of the DNA, and then deliver a package which does something, like splice the DNA. But you also need to target the correct cells. In a petri dish, this is simple. But in living organism, this is a huge challenge. We have developed several viral vectors that can be targeted to specific cell types in order to deliver the CRIPR (or TALEN), which then targets the specific DNA.

Now I would like to present a different technique I have not previously written about here – alternative splicing. A recent study presents what seems like a significant advance in this technology, so it’s a good time to review it. “Alternative splicing” refers to a natural phenomenon of genetics. Genes are composed of introns and exons. I always thought the nomenclature was counterintuitive, but the exons are actually the part of the gene that gets expressed into a protein. The introns are the part that is not expressed, so they are cut out of the gene when it is being converted into mRNA, and the exons are stitched together to form the sequence that is translated into a protein. Alternative splicing refers to the fact that the way in which the introns are removed and the exons stitched together can vary, creating alternative forms of the resulting protein. This dramatically increases the number of different proteins that an organism’s genes can code for, because each gene can potentially code for multiple protein variants through alternative splicing.

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Oct 07 2022

Chicxulub Impact Triggered Mega-Earthquake

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At this point there is little question that a giant asteroid, 10 kilometers across, impacted the Earth about 66 million years ago. Evidence for this impact began with an iridium layer discovered at the Cretaceous-Paleogene, or K-Pg, boundary. Something deposited an unusually high level of iridium in a brief event all around the world. Later the likely crater resulting from this impact was found in Chicxulub, Mexico. Multiple other discoveries have supported this conclusion, including the fact that this impact was the likely cause of the dinosaur extinction. There was also massive volcanic activity at that time, and dinosaur populations may have been in decline, but that was likely a side show. The main event was the impact.

Such an impact would have released a tremendous amount of energy (10^23 joules), equivalent to a 100 million megaton bomb. There were multiple effects of that impact. One is that a lot of Earth crust material would have been melted and thrown up into the atmosphere, but at less than escape velocity so ultimately raining back down to Earth. Some of these molten droplets cooled into glass spherules as they fell, raining tiny glass beads onto the Earth – creating another geological marker for the impact.

The asteroid impact was essentially in the Gulf of Mexico, causing a massive tsunami that swept over North America. My favorite geological find resulting from this is at the Tanis site in Hell’s Creek. The massive tsunami washed lots of fish and other sea life across the continent, and deposited them in a valley, creating a large jumble of fossils all deposited at once. Scientists know they are from the day of the impact because the fish have glass spherules stuck in their gills – they breathed them in while still alive.

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Sep 16 2022

Green Transition Will Save Money

Published by under General Science

It is difficult to project costs into the future, because there are many variables and small errors magnify over time. But still, statistical modeling can be done and validated to produce reliable estimates that can at least inform our discussion. There have been many methods of modeling the cost of global warming vs the cost of transitioning to net-zero carbon.  In general they find that, while there will be costs to transitioning to green technology, there will also be overall savings from reducing global warming.

A new study takes a different approach from previous one – they do not consider the effects of global warming at all, but rather only consider the cost of energy itself. This is basically an ROI approach – we will need to invest a lot of money in new infrastructure, but as a result we will have cheaper electricity, so how does that net out. The bottom line is that under every scenario they consider, transitioning to green energy technologies will save billions of dollars per year in energy costs, and trillions over the entire transition. But let’s look at some of the variables they have to consider.

One thing they did different than prior economic analyses was to try to more accurately model the future costs of green technologies (wind, solar, batteries). Other studies take a conservative approach, but they have all underestimated the decreasing costs of these technologies. So the researchers in the new study more accurately modeled past predictions compared to actual costs and came up with a more accurate model that they validated with historical data. More accurately modeling the likely future decrease in the costs of these technologies increased the likely savings from transitioning to them.

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