Archive for the 'General Science' Category

Jun 02 2022

Surviving a Global Catastrophe

Published by under General Science

On the most recent season of Love Death and Robots (which is excellent, btw) the first episode sees the return of the three robot explorers from previous seasons. They are looking over the remains of human civilization trying to figure out what went wrong. It’s a clever and funny commentary on some of our more irrational social ills and how fragile civilization can be. And while the apocalypse is primarily a plot device for survivalist and zombie movies, it is a serious issue and something we can plan for.

No one wants to think about the worse-case scenario, or confront it as a real possibility. There are survivalists and preppers who seem to romanticize the idea – if you put so much time and effort into preparing for something, it can be seen as anti-climactic if it never happens. But it does make sense to prepare for contingencies that you truly hope never happen. Also, preparing for a global catastrophe should in no way detract from our attempts at preventing catastrophe. It should not be a form of giving up. Rather, we’re just hedging our bets. We should spend the majority of our efforts preventing disaster, but just in case.

One example of this is the Svalbard global seed vault. In case there is some agricultural apocalypse, such as a blight, or some other collapse of global civilization, a large stock of seeds of all agriculturally important plants are kept preserved in the vault. We could use this as an emergency supply to reboot our agricultural system. Hopefully we will never need to crack open the vault (metaphorically) but in case we do, it’s nice to know that it’s there.

A recent paper (expanding on prior research) explores the practicality and utility of civilization refuges as a hedge against global catastrophe. The authors argue that we should at least think about which locations in the world would be most resilient in the face of, for example, a global pandemic. What if we have a pandemic similar to COVID except ten times or even a hundred times more deadly. COVID is now at 6.3 million global deaths. What if it were 63 million, or 630 million? These are plausible scenarios, and we would be foolish not to take reasonable steps to prevent them, mitigate them, and prepare for them. Again, prevention is the best option, but we need to prepare for failure leading to a worst-case scenario.

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May 17 2022

Health Benefits of Clean Energy

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What if there were a change we could make in our society that would save, in the US alone, more than 50,000 lives per year and avoid more than $600 billion every year in health care costs and lost productivity? How much should we invest each year to make the necessary changes? Even if we invested $3 trillion over the next 10 years, that would only be half as much as we would save over the same length of time (in addition to preventing have a million premature deaths). Would you say that was worth it? It sounds like a good deal, but of course we have to delve into the details.

I am talking, as you probably guessed from the title, about clean energy. Burning fossil fuels releases particulate matter into the atmosphere, which causes respiratory illness and increases the risk of stroke and heart attack. Coal is worse than oil is worse than natural gas, but they are all a problem. A newly published study set out to estimate the societal costs just from the perspective of health to the energy, transportation, and manufacturing industries and their use of fossil fuel. Here are the key findings from the abstract:

In this study, we estimate health benefits resulting from the elimination of emissions of fine particulate matter (PM2.5), sulfur dioxide, and nitrogen oxides from the electric power, transportation, building, and industrial sectors in the contiguous US. We use EPA’s CO-Benefits Risk Assessment screening tool to estimate health benefits resulting from the removal of PM2.5-related emissions from these energy-related sectors. We find that nationwide efforts to eliminate energy-related emissions could prevent 53,200 (95% CI: 46,900–59,400) premature deaths each year and provide $608 billion ($537–$678 billion) in benefits from avoided PM2.5-related illness and death. We also find that an average of 69% (range: 32%–95%) of the health benefits from emissions removal remain in the emitting region.

Even if these estimates are off by a factor of two or three, which is unlikely, we are still talking about 2-3 hundred billion dollars per year. Therefore, from a purely economic perspective, investing in clean energy is a good deal for the US, its people, and our economy. It would be economically irresponsible if we did not heavily invest in making the transition to clean energy as quickly as possible. It is important to realize the bottom line here – we can justify heavy investment in clean energy just from a health and health-related cost perspective alone. Even if you are a denier of global warming and its impacts, you should still support clean energy and rapidly phasing out fossil fuels.

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Apr 11 2022

The Day the Dinosaurs Died

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This is one of the coolest science news stories of the last decade, and I’m a bit surprised it’s not getting more play. Paleontologists have discovered and been examining a fossil deposit from the exact day that the asteroid hit 66 million years ago, at the K-Pg boundary. The site is in Tanis (isn’t that where the Ark of the Covenant was found?) North Dakota (Oh, so no).  Actually it’s the Tanis site within the Hell’s Creek formation, which is a productive fossil bed. How can scientists be sure what they are looking at comes from the time of impact? That’s one of the interesting parts of the story.

What appears to have happened is that a large asteroid, about 12 km wide, struck the Yucatan peninsula in the Gulf of Mexico. The crater (Chicxulub crater) from the impact can still be seen. The impact threw a lot of material up into the atmosphere. It also caused a massive tidal wave that spread out, sending material along the Gulf shore, across Mexico, and up along the coasts. But part of this wave also snaked north along a riverbed that led inland to where modern day Tanis is, 3,000 km away. There the water came to rest in a large basin. The wave had swept up sea and land creatures, depositing them in a jumble in the basin. That is one of the lines of evidence that this fossil deposit is a direct result of the impact, the mix of land and sea creatures so far inland, and the fact that the deposit appears to be the result of a sudden chaotic event. It would take something massive to do that, like a meteor impact in the gulf.

An interesting technical detail is that the wave was likely only partly a tidal wave phenomenon from the “splash” of impact. Published evidence indicates that the deposit also likely coincided with a seismic wave – a harmonic wave in the body of water resulting from the impact. So it was more like a megatsunami.

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Apr 01 2022

Wind and Solar Hit 10%

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The percentage of world electricity generated by wind and solar energy hit 10% in 2021 according to a recent analysis. Total clean energy (including nuclear, hydro, geothermal, and bioenergy) was 38% of world electricity, exceeding coal at 35%.  Gas was 22%, for a total fossil fuel contribution of 57%. Also, total demand for electricity rose sharply in 2021, partly due to the bounce back from the pandemic, with coal rising 9% total and making up most of the increased demand – so this is a very mixed story.

According to the analysis there are two major forces at work across the world in determining the relative growth of the various sources of electricity, economics and regulations. In political fights over energy (including frequently in the comments to this blog) people will often assume one or the other factor is the only or the major factor involved. For example, the argument has been explicitly made that economics is the only relevant factor and policy is therefore irrelevant, but that is demonstrably not true. Neither is the notion that we can totally control the energy sector through policy without consideration of economic factors. That approach is likely to lead to policy overreach with backlash and unintended consequences. Both factors are involved, and a rational energy policy should consider the relevant economics.

For example, coal surged in 2021 because it is cheap relative to its major competitor, gas. Both rose in price, but gas rose much more than coal, so coal predominated. However, wind and solar are cheaper than both, so they also rose significantly. Even though they are now the cheapest option for adding new capacity, they were outpaced by coal because of regulations and infrastructure – showing that price alone is not the only determining factor.

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Mar 25 2022

Using CRISPR to Turn Genes On

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Last year I wrote about CRISPR On-Off – this is a system for using the genetic modification tool, CRISPR, in order to turn the expression of a gene off and then back on again, without altering the gene itself. Now researchers have published a similar application of CRISPR, using a different mechanism to turn on the expression of silenced genes. Their technique shows the power of CRISPR as a modifiable platform. The research also used AI to design the new system, again showing how artificial intelligence is being used to dramatically speed up the pace of research.

The new technique also uses CRISPR (Clustered regularly interspaced short palindromic repeats), which was derived from bacteria that use it as part of their immunity against viruses. CRISPR is like a carrier, which can be attached to a specific stretch of DNA. It will then find that stretch of DNA within a genome and target it. CRISPR can also be attached to a variety of proteins, most famously CAS9, which can then perform some function when it gets to its target. CAS9 is a DNA splicer, so a CRISPR-CAS9 system can target a desired stretch of DNA and splice it. This can be used to disrupt a gene, or it can be used to create a location for the insertion of a new gene or gene modification, which requires a separate process involving the DNA repair mechanism.

The CRISPR system dramatically reduced the cost and time necessary to make alterations to a genome. The technology is also rapidly progressing, because research using CRISPR is now available to many more labs and researchers. There are other payloads other than CAS9 that can be used, for example. Researchers are also learning how to tweak the speed vs accuracy of CRISPR.

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Mar 24 2022

Organic Insecticide Harmful to Beneficial Insects

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As I have discussed many times on this blog, organic farming is an ideological approach to farming that is ultimately harmful to the environment and agriculture. This is because it is not evidence-based, but rather is based on a dubious philosophy, the notion that methods that are more “natural” (a poorly defined concept) are inherently safer and superior to methods that are “artificial”. The term “organic” is mainly used as a marketing term to create a health halo around products that allow for charging an ideological premium, without any proven benefit.

One aspect of organic farming is that it does not allow for the use of synthetic pesticides, but does allow for the use of natural pesticides. Conceptually this makes no scientific sense – substances which occur in nature can be deadly poisons, just as synthetic substances can. The degree to which something is “natural” is completely orthogonal to how safe or toxic it is to various domains of life. Using natural as a proxy for safety is therefore a completely unscientific and nonsensical approach, but that is organic farming.

Pest management is one of the greatest challenges of modern agriculture. The problem comes from the fact that we are packing in rows and rows of the same crop. That presents an attractive food source to anything that can eat it. Pests can be devastating to crops, and so keeping them under control is necessary for successful agriculture. There are a number of methods that can be used, and experts generally recommend what is called integrated pest management (IPM), which uses multiple methods to reduce pest burden on crops. IPM includes the judicious use of pesticides where necessary, and both conventional and organic farming uses pesticides with organic farming limiting itself to those it deems “natural”.

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Mar 14 2022

De-Extinction of the Tasmanian Tiger

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The last known thylacine, commonly known as the Tasmanian tiger, was in captivity in 1936. This marsupial predator was wiped out by human hunting. At the time Europeans colonized Australia the range of the thylacine was limited to Tasmania, but it did not survive contact with Europeans for very long.

The thylacine is now one of the primary targets for de-extinction – literally bringing the species back from extinction using cloning technology. This effort has just received a significant boost. The University of Melbourne just received a $5 million grant to develop their Thylacine Integrated Genetic Restoration Research (TIGRR) Lab. Scientists love their clever acronyms, and I wonder how long they had to work on this one.

The researchers at the lab have a specific plan in terms of how to bring back the thylacine. They have already completed the first step, which is to completely sequence the thylacine genome. Now they need to study this genome to understand it as best as they can. They will need to synthesize a complete genome, and then place it in stem cells prepared from another marsupial. This is where the cloning process comes in. You remove the DNA from the stem cell, insert the new DNA, and then coax the cell into dividing to form an embryo. They then plan to implant the embryo into a living host, such as a Tasmanian devil, who will then give birth to a live thylacine.

The process is tricky. We have cloned large mammals before, but not of an extinct species. Also, the process is not done when we have one thylacine. The goal is to create a breeding population. That means we need many individuals, both male and female, with sufficient genetic diversity. Once they have established a breeding population in captivity, the ultimate goal is then to reintroduce them back into the ecosystem of Tasmania.

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Mar 03 2022

Exuviae and Frass for a Circular Farming System

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What are exuviae and frass? These are terms I just learned and are probably new to you as well, but they may become more familiar in the future. Exuviae are molted exoskeletons from insects and are primarily made of chitin. Frass is undigested food from insects, so basically bug poop. Frass could make a good fertilizer for plants because it is high in nitrogen. Exuviae would not serve as fertilizer, but there are species of soil bacteria that can break down chitin for food. Adding exuviae to soil increases the population of these soil bacteria, which are beneficial to plants and make them more resilient to pests.

Exuviae and frass, therefore, can be extremely useful for farming. But where are we going to get the massive quantities of these materials that would be necessary to have any significant impact on our agricultural system? Well, we could farm insects for food and use the waste products of insect farming for plant agriculture. This could be the basis for a circular agricultural system. Organic matter from plant and animal farming can be used to feed insects which are also grown for food. The exuviae and frass from the insect farming can then be fed back into plant farming as fertilizer. This would not be a totally closed system, of course. Humans would be removing calories and nitrogen from the system to feed themselves, and human waste is typically not recycled as fertilizer (this is a separate issue – the risks and benefits of using humanure).

Insects are increasingly recognized as an important source of food. They have several advantages, the biggest being that they are small. This translates into a high food output to land use ratio. Raising insects also uses far less water than other food sources. Insects can also be easily farmed indoors, meaning they can be farmed year-round and in urban settings. Already there is significant farming of crickets, grasshoppers, mealworms, waxworms, and other insects for food. The insects are not generally consumed whole (although they can be), they are ground up and used as protein powder (such as cricket flour).

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Feb 28 2022

Some Good News on Climate Change

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One of the challenges of being a science communicator is keeping up to date. About 2.5 million scientific papers are published every year. Most of this is noise, preliminary studies, speculations, etc., but the end result is that most fields of science are constantly changing. This became very concrete for me while writing my next book (shameless plug alert), The Skeptics Guide to the Future, coming out this Fall. A big part of the book is examining cutting edge science and technology and then extrapolating it into the near, midterm, and far future. During the editing process there were constantly science news items that required small updates to the book. In fact I had to ask my editor, after the final submission, if I could please squeeze in one more update, and promised it would be the last one.

If you are not paying obsessive attention to a particular field of science, it’s really difficult to keep completely up to date. There is also a substantial delay, sometimes decades, between changes to the consensus of scientific opinion based on new evidence and when that new consensus filters down to the public’s general consciousness. Sometime the delay is forever, as outdated ideas persist indefinitely. This is especially true if an outdated scientific conclusion has a rhetorical utility, either in marketing a product or promoting a political ideology. We figured out a quarter of a century ago that consuming anti-oxidants were not good for your health, but don’t hold your breath for the supplement industry to alter their promotion of anti-oxidant products.

One idea that has become a standard part of the conversation on climate change is that once CO2 is released into the atmosphere it will cause continued warming for decades. So, the argument goes, even if we stopped all release of greenhouse gases today, full net-zero, the climate would continue to warm for many decades, perhaps a century or longer. That was the scientific consensus, although it was never a very firm one, just the best estimate based on existing evidence. That conclusion, however, started to crack as early as 2008, and by 2020 was updated with new and better science. This is a rare instance of good climate news. In an interview, climate scientist Michael Mann said:

“This really is true,” he said. “It’s a dramatic change in the paradigm that has been lost on many who cover this issue, perhaps because it hasn’t been well explained by the scientific community. It’s an important development that is still under appreciated. It’s definitely the scientific consensus now that warming stabilizes quickly, within 10 years, of emissions going to zero.”

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Feb 01 2022

DNA Microfossils and the Woolly Mammoth

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About 12 thousand years ago the late Pleistocene was transitioning to the current Holocene. This transition was marked by the end of the last glacial period, and turnover of entire ecosystems to a new homeostasis. Specifically in the Arctic North America, the mammoth-steppe biome was transitioning to the boreal forest we know today. As the name suggests, the most famous of the megafauna of the late Pleistocene was the woolly mammoth, and a lot of research has focused on nailing down the exact date when the woolly mammoth went extinct.

Dating the lifespan of a species is always a matter of finding the earliest and latest evidence for its existence. Such date ranges are always an underestimation, because it’s unlikely that we have discovered the very first or very last specimen, so it is very common for new fossil discoveries to expand the known date range. This is why headlines such as, “Woolly Mammoths Survived Longer than Previously Thought” are extremely common. Of course they did – most extinct species survived longer than we currently think.

However, it is not common that scientists hit upon an entirely new method for exploring the past and dating species, but that is what is happening now. Researchers from the McMaster Ancient DNA Centre are pioneering a technique to explore ancient environmental DNA. This is made possible by the extreme advances in genetics technology over the last few decades. Already environmental DNA is giving us a new powerful tool to explore ecosystems. We no longer have to track and tag representatives of all the species in an environment to get a sense of what plants and animals live there. We can just take a few scoops of soil and water and sequence the environmental DNA that we find. Every living things sheds DNA into the environment, and as their remains decay into the soil and water it spills their DNA for scientists to find later. My favorite application of environmental DNA technology is a survey of Loch Ness showing the complete absence of DNA from a plesiosaur or any similar creature.

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