Drowning of Coastal Marshland in Louisiana is Likely Inevitable


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Thomas Robinson | May 25th, 2020

Coastal marshes in the Gulf of Mexico have been shown to have tipping points in a new study.  Tipping points, are when coastal marshes are unable to keep up with the rate of sea-level rise and become submerged over time destroying the marsh ecosystem.

Sediment cores were used from the Mississippi Delta to investigate how coastal marshes reacted to changes in their environment over the past 8,500 years.  Researchers found that even a small increase in the rate of sea level rise would result in large areas of coastal marshland becoming submerged.  Researchers found that rates above 3 millimeters per year is the likely threshold for coastal marshes to survive.  Unfortunately, current rates of sea-level rise are beyond that threshold suggesting that the remaining marshes in the Delta will likely drown within the century.

Coastal wetlands, such as marshes, are one of the most valuable ecosystems in the world.  They are extremely productive regions that have significant environmental and economic benefits.  They provide homes for diverse ecosystems that can benefit species diversity which results in robust fisheries.  Coastal wetlands also provide flood protection and erosion control for coastal areas which help to reduce the effect storms have on the coastline.

As coastal wetlands in the Mississippi River Basin are stressed from sea-level rise, they are also inundated with sediment and nutrients flowing from upstream.  Iowa is a major contributor to this issue and even though efforts are underway to alleviate the stress, coastal wetlands will be negatively affected by the state’s agriculture for years to come.

Dangerous Heat Events Are Becoming More Common


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Thomas Robinson | May 19th, 2020

Extreme heat events that threaten human safety are already occurring contrary to current climate projections, says a recent study

Researchers found that high heat events where the temperature and humidity exceed safe conditions have occurred twice as often since 1979.  These dangerous heat events occur in coastal regions like the Gulf of Mexico and southeastern California but can also occur in areas with heavy irrigation and agriculture.  The most extreme heat events were both localized and short (1-2 hours) but all signs suggest that they will only become more frequent as climate change worsens. 

The key measure in the study was the “wet-bulb temperature”, which describes what the temperature feels like if a person is actively sweating.  A sustained wet-bulb temperature of 95˚F (or a heat index of 160˚F) is the point where the sustained heat becomes deadly, but even temperatures slightly below pose dangers to the elderly or those with complications. 

Iowa is heat prone itself as our state can be extremely humid even before the addition of corn.  The 2019 Iowa Climate Statement emphasized the likelihood of more frequent, and severe heat events for Iowa, and that those events will pose a threat to workers and the elderly.  As the likelihood of dangerous heat events increases, so too does the likelihood that heat becomes a frequent concern for those in Iowa and around the world.

Climate Change Could Improve Hydropower Generation


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Thomas Robinson | May 12, 2020

Researchers suggest that climate change will result in a larger benefit to hydropower generation if the 1.5˚C Paris climate goal is met, than if it is exceeded.

The researchers modelled how climate change would influence hydropower production for the tropical island of Sumatra and found a 40% increase in the ratio of hydropower production to demand at the 1.5˚C mark compared to 2.0˚C.  The model used by the researchers included both climate, and economic factors which were used to explore how increased temperatures would influence hydropower potential.  The study emphasized the importance of finding optimal locations for new hydropower plants considering the reality of a changing climate. 

Hydropower is an essential resource for the world’s carbon free energy supply and is expected to be an important component for improving energy systems around the world. In Iowa, wind and solar energy make up a larger fraction of Iowa’s renewable energy than hydropower.  In 2018, only 1.5% of Iowa’s electricity was generated from hydroelectric sources but it is thought that approximately 5% of the state’s electricity usage could come from hydropower if changes were made. 

Scientists Discover a New Method to Make Wheat More Climate Resilient


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Thomas Robinson | May 5th, 2020

Researchers have recently been able to develop a more heat resistant bread wheat through amino acid substitution. 

In a recent study, a single amino acid associated with Rubisco, an essential plant enzyme involved in photosynthesis, was substituted and was able to extend the temperature optimum for wheat by 5˚C.  The researchers suggest that their technique could be used to adapt crops to improve their resilience in a changing climate.

Rubisco is an energy producing enzyme plants use to collect carbon from the atmosphere, which is then used to create organic sugars.  It is thought that Rubisco is the most abundant enzyme on earth as it is found in most plants that use photosynthesis.  Previous work has shown that these enzymes are susceptible to climate change and could be negatively influenced as temperatures increase. 

In Iowa, climate change is projected to increase high heat events which will increase heat stress on agricultural crops such as wheat. By exploring methods for reducing heat stress, researchers are able to provide novel solutions for mitigating the adverse effects climate change may have on agriculture.

Terrestrial Insect Populations Have Decreased Over The Past Couple of Decades


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Thomas Robinson | April 28th, 2020

Terrestrial insect populations are declining, according to a study released this month. 

Researchers analyzed over 150 insect surveys to clarify concerns about declining insect populations and found that terrestrial insect populations decreased by 9% per decade, while freshwater insect populations increased by 11% per decade.  The researchers placed emphasis on the fact that data were scarce from land areas with high urban and agricultural use, which suggests that the actual rate is higher than a 9% decline per decade.

Insect population decline has been the topic of recent research which warns of a catastrophic decrease in insect populations across the globe.  Since the 1970’s, it is estimated that the abundance of insects has declined by around 50%.  Insects are an essential component of our globe’s ecosystems and the decline in populations signals an unseen risk to the environment.

In Iowa, one trend that is likely to contribute to the decline in insect populations is the extensive use of pesticides such as neonicitinoids, which are a key suspect for the decline in many insect species such as bees.  Iowa has seen an increase in the amount of neonicitinoids applied since 2004 as they have been proven to be an effective insecticide if applied as a seed coating.  With the continuing trend of increased pesticide use in Iowa it is unlikely insect populations will halt their decrease in our state anytime soon.

Solar Jobs Census shows an Increase in American Solar Jobs for 2019


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Thomas Robinson | April 21, 2020

Almost 250,000 Americans worked in solar jobs as of 2019, a 2.3% increase since 2018 as reported in the 10th annual National Solar Jobs Census.  The solar industry is seeing an increase in employment after decreasing numbers the past two years.  The results of the census are summarized in an interactive website which provides data for each state down to the county scale.

Iowa employed over 800 people with solar jobs in 2019, ranking 39th in the country.  While not a leader in solar energy, Iowa is the state with the second highest wind energy capacity, with wind energy representing more than a third of the state’s electricity production as of 2016.  Renewable energy represents almost two-fifths of Iowa’s electricity generation, and the proportion is only expected to continue to increase.

Employment in solar nationally has increased by over 167% within the past decade alongside a 70% drop in cost within the same time frame.  To ensure the future of solar energy, an MIT study suggests that government policies are required to incentivize it’s use and to continue the growth caused by the continuing drop in prices.

COVID-19 Mortality Risk Increases with Increased Exposure to Poor Air Quality


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Thomas Robinson | April 14th, 2020

A recent Harvard study has presented a link between air pollution and a heightened mortality risk from COVID-19. Models developed by the researchers predict a 15% increase in COVID-19 death rates if the concentration of fine particulate matter increased by a small amount (1 microgram per meter cubed).

Particulate matter in the air comes from sources of dust or sooty emissions, such as agricultural fields or factories.  There are two common sizes of particle pollution, PM10 (large) and PM2.5 (fine), where the number indicates the average diameter of the particles in micrometers.  For reference, an average human hair is approximately 70 micrometers in diameter, meaning that a PM2.5 particle is about 30 times smaller than a human hair.

It is well known that air pollution has harmful effects on human health, and that air pollution measures such as the Clean Air Act have a positive influence on human health outcomes.  What is becoming more apparent as COVID-19 continues to affect the globe is that improvements in air quality can result in measurable improvements for human health moving forward.  For example, the study suggests that if the long-term average PM2.5 in Manhattan had been reduced by 1 µg/m3 there might have been 248 fewer deaths associated with COVID-19 as of April 4th in New York County.