Category Archives: Peer Reviewed Article Review

a new dust bowl

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Sure, the U.S. has problems, and we are not doing a great job solving or even acknowledging all of them. Still, soil conservation is something we have had figured out since the 1920s, right? Not so fast, my friends. As we keep pushing for increased production, the amount of dust in the air (this is something we measure) keeps increasing. Warming and drying trends are not going to help.

This is Geophysical Research Letters.

Climate change and land use are altering the landscape of the U.S. Great Plains, producing increases in windblown dust. These increases are investigated by combining coarse mode aerosol observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor in addition to the Aerosol Robotic Network (AERONET) and Interagency Monitoring of Protected Visual Environments (IMPROVE) aerosol monitoring networks. Increasing trends of up to 5%/year in MODIS aerosol optical depth for dust observations are observed throughout the Great Plains (2000–2018). Cropland coverage has increased 5–10% over the majority of the Great Plains (2008–2018), and positive monthly trends in IMPROVE (1988–2018) and AERONET (1995–2018) coarse mode 90th percentile observations coincide with planting and harvesting seasons of predominant crops. Presently, results suggest increased dust due to agricultural expansion is negatively influencing human health and visibility in the Great Plains. Furthermore, results foreshadow a future where desertification becomes an increasing risk in the Great Plains.

ice loss following worst case predictions

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Treehugger, summarizing an article in Nature Climate Change (which you can’t read without belonging to a university library or paying a lot of money) says loss of ice in Greenland, Antarctica, and around the world is tracking the most pessimistic model results included in the most recent IPCC report.

Up until this point, global sea levels have increased mostly due to thermal expansion, which means the volume of seawater expands as it gets warmer. However in the last five years, water from melting ice sheets and mountain glaciers has become the primary cause of rising sea levels, the researchers point out.

It’s not only Antarctica and Greenland causing sea level rise. The researchers say that thousands of smaller glaciers are melting or disappearing completely.

Treehugger

I think it may be time to get away from coastlines, hot places, and dry places. But not so far north I have to deal with thawing permafrost. And I don’t want to deal with earthquakes or volcanoes. This would seem to leave limited choices.

humidity helps reduce coronavirus transmission

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Humidify those schools!

The relationship between climatic factors and COVID‐19 cases in New South Wales, Australia was investigated during both the exponential and declining phases of the epidemic in 2020, and in different regions. Increased relative humidity was associated with decreased cases in both epidemic phases, and a consistent negative relationship was found between relative humidity and cases. Overall, a decrease in relative humidity of 1% was associated with an increase in cases of 7–8%. Overall, we found no relationship with between [sic] cases and temperature, rainfall or wind speed.

Transboundary and Emerging Diseases

Not being a scientist or doctor, I have always assumed that mucous membranes inside your nose help block germs, and that a dried out nose in the winter time is one reasons colds, coughs, and flu spread through schools and offices every winter. It seems like a relatively simple measure to take that would have a clear positive effect. Now, to sit back and wait for my children’s schools and my office building manager to explain why it can’t be done.

“jaw dropping” reduction in global fertility rate

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A study in Lancet says the data are starting to show large reductions in global fertility rates, which are likely to lead to declining population growth and then a declining population as the century wears on.

The global TFR in the reference scenario was forecasted to be 1·66 (95% UI 1·33–2·08) in 2100. In the reference scenario, the global population was projected to peak in 2064 at 9·73 billion (8·84–10·9) people and decline to 8·79 billion (6·83–11·8) in 2100. The reference projections for the five largest countries in 2100 were India (1·09 billion [0·72–1·71], Nigeria (791 million [594–1056]), China (732 million [456–1499]), the USA (336 million [248–456]), and Pakistan (248 million [151–427]). Findings also suggest a shifting age structure in many parts of the world, with 2·37 billion (1·91–2·87) individuals older than 65 years and 1·70 billion (1·11–2·81) individuals younger than 20 years, forecasted globally in 2100. By 2050, 151 countries were forecasted to have a TFR lower than the replacement level (TFR <2·1), and 183 were forecasted to have a TFR lower than replacement by 2100. 23 countries in the reference scenario, including Japan, Thailand, and Spain, were forecasted to have population declines greater than 50% from 2017 to 2100; China’s population was forecasted to decline by 48·0% (−6·1 to 68·4). China was forecasted to become the largest economy by 2035 but in the reference scenario, the USA was forecasted to once again become the largest economy in 2098.

Lancet

In my time living, working and traveling in Southeast Asia, I saw firsthand that at least some highly educated women are choosing to prioritize career over marriage and children. That pattern may be taking hold on a larger scale as larger countries move from middle income to higher income. Opportunities and choices for women are a good thing, of course, but there are some concerns about who will do the work and pay the taxes in such a world. We’re fretting about the effects of automation on employment, but if the work force is going to shrink anyway, and the jobs that do remain are going to require more education and skills, it seems like there is an opportunity to try to pair the pace of automation to the pace of natural work force reduction. The solutions are nothing new – we need to invest in childcare, education, training, research and development, unemployment insurance, and strong pension systems. We may need stronger measures to share the wealth, like a universal endowment at birth or a universal basic income.

Then there’s environmental impact. Malthus aside, without policy changes the effects of a population that is becoming more affluent and consuming more will probably outweigh the effects of a shrinking human population. We can’t just keep paving the world, pumping the groundwater, massively altering the oceans and atmosphere, driving more and eating more meat forever and expect it not to catch up to us.

teeth: miracle or weakness of evolution?

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I’ve always thought that teeth might be the weakest point of the human body. Why did our teeth evolve to be made of calcium, which dissolves in acid, when pretty much all our food is acidic? Why do we have to strap metal torture devices to children’s teeth for years just for them to be reasonably straight? Why don’t animals seem to have these problems?

This article in Scientific American sings the praises of teeth. It argues that, like many of our other organs and systems, our modern lives just aren’t what they evolved to deal with. It basically comes down to the idea that our food is too sweet and too soft.

The evolutionary history of our teeth explains not only why they are so strong but also why they fall short today. The basic idea is that structures evolve to operate within a specific range of environmental conditions, which in the case of our teeth include the chemicals and bacteria in the mouth, as well as strain and abrasion. It follows that changes to the oral environment can catch our teeth off guard. Such is the case with our modern diets, which are unlike any in the history of life on our planet. The resulting mismatch between our biology and our behavior explains the dental caries (cavities), impacted wisdom teeth and other orthodontic problems that afflict us.

Scientific American

I admit, I don’t like working for my food – I like boneless, seedless, shell-less everything. My teeth may have paid the price.

integrating movement ecology and biodiversity research

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This article talks about two sub-disciplines of ecology that have developed independently and would benefit from more integration. One is about the movement of individual animals, whether natural or fragmented/impacted by humans. The other is about the variety of organisms and how they interact with each other in habitats.

Editorial: thematic series “Integrating movement ecology with biodiversity research”

Bridging the gap between biodiversity research and movement ecology is possible. First integrations demonstrated that individual movement capacities and strategies are critical in determining the persistence of species and communities in fragmented landscapes, with changing climatic conditions, or in the presence of invasive species. At the same time, the ever-increasing human impact on nature puts long-established movement patterns in jeopardy, and organismal movement is changing perceivably across scales. Yet, a full-fledged integration of movement ecology and biodiversity research is still in its infancy. Empirically, we need more studies that not only focus on the movement of individuals, but also how they interact, while moving, with their environment and with other individuals, including their own and other species. From a theoretical viewpoint, there is a lack of modelling approaches that integrate individual movement and its consequences with population and community dynamics.

Movement Ecology

This could potentially be helpful at a time when remaining natural habitats are becoming increasingly fragmented, and are interspersed with agricultural, urban and suburban environments. All this could be optimized, given the right theory. Professional and political understanding and willingness to act would have to follow, of course, but doing the science would be a necessary first step.

Technosols

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A technosol is an artificially created planting/structural medium from manmade materials, such as construction debris and compost. This article from Ecological Engineering journal says a mix of 20% “excavated deep horizons” (in layman’s terms, I think this is just dirt from construction sites), 70% crushed concrete, and 10% compost might work. If we truly want green cities, and we don’t want to reduce natural habitats to wastelands by harvesting materials from them to green our cities, this could be a good approach.

CDC in the ICU?

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I’m not the only one disappointed in the CDC. The Lancet has a scathing editorial.

The US Centers for Disease Control and Prevention (CDC), the flagship agency for the nation’s public health, has seen its role minimised and become an ineffective and nominal adviser in the response to contain the spread of the virus. The strained relationship between the CDC and the federal government was further laid bare when, according to The Washington Post, Deborah Birx, the head of the US COVID-19 Task Force and a former director of the CDC’s Global HIV/AIDS Division, cast doubt on the CDC’s COVID-19 mortality and case data by reportedly saying: “There is nothing from the CDC that I can trust”. This is an unhelpful statement, but also a shocking indictment of an agency that was once regarded as the gold standard for global disease detection and control. How did an agency that was the first point of contact for many national health authorities facing a public health threat become so ill-prepared to protect the public’s health?

The Lancet

Well, you can read the rest for yourself, but the answer to the question is defunding and political interference.

“supporting” ecosystem services in cities

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This long article makes a distinction between services provided by natural and semi-natural areas in cities, and a concept of a city as a whole as an ecosystem that provides services. What it reminded me of, though, is the distinction between the UN’s definition of “regulating” ecosystem services and “supporting” ecosystem services.

• Regulating ecosystem services, such as control of stormwater discharge, mitigation of heat in urban areas, mitigation of noise, etc.

• Supporting ecosystem services, such as provision of habitats for urban biodiversity, provision of pollinators for urban farms, etc.

Journal of Landscape and Urban Planning

In the engineering world I inhabit, we have the regulating services reasonably well figured out. We don’t always do a great job of implementing and enforcing, and we exempt too many projects, but basically we have cost-effective standards and best practices for things like flood management and water pollution reduction.

The supporting ecosystem services are mostly not even on our radar. And that means that when we are designing for flood or water quality objectives, our designs are not as green as they might be if we took biodiversity and habitat into account. It might not even cost more to do that, but it would require a more expansive way of thinking. To do that, we would need to communicate effectively to the decision makers and then the rank and file just why they should care.

drought

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Alarm bells are beginning to sound on drought risk in western North America and around the world, including some important and populous food growing regions.

Here’s an article in Science talking about “an emerging North American megadrought”:

Severe and persistent 21st-century drought in southwestern North America (SWNA) motivates comparisons to medieval megadroughts and questions about the role of anthropogenic climate change. We use hydrological modeling and new 1200-year tree-ring reconstructions of summer soil moisture to demonstrate that the 2000–2018 SWNA drought was the second driest 19-year period since 800 CE, exceeded only by a late-1500s megadrought. The megadrought-like trajectory of 2000–2018 soil moisture was driven by natural variability superimposed on drying due to anthropogenic warming. Anthropogenic trends in temperature, relative humidity, and precipitation estimated from 31 climate models account for 47% (model interquartiles of 35 to 105%) of the 2000–2018 drought severity, pushing an otherwise moderate drought onto a trajectory comparable to the worst SWNA megadroughts since 800 CE.

Science

Here’s an article in Earth’s Future (from the American Geophysical Union, which I consider prestigious) talking about some other regions with high drought risk.

The multi‐model ensemble shows robust drying in the mean state across many regions and metrics by the end of the 21st century, even following the more aggressive mitigation pathways (SSP1‐2.6 and SSP2‐4.5). Regional hotspots with strong drying include western North America, Central America, Europe and the Mediterranean, the Amazon, southern Africa, China, Southeast Asia, and Australia. Compared to SSP3‐7.0 and SSP5‐8.5, however, the severity of drying in the lower warming scenarios is substantially reduced and further precipitation declines in many regions are avoided. Along with drying in the mean state, the risk of the historically most extreme drought events also increases with warming, by 200–300% in some regions.

AGU

So, our species has identified the problem and identified solutions, but is continuing to fail to actually do anything. This is a little like the coronavirus, where early action could have been cheap and effective compared to the drastic action required when the problem became really obvious to even the densest politicians. It’s unlike the coronavirus in that once the problem becomes obvious to even the densest politicians, there may be no effective measures that can be taken, even maximally disruptive ones.

The mention of the Amazon and Southeast Asia are particularly concerning to me. These are both important food growing regions and biodiversity hot spots.