Interactive tool to predict future days above 100 degrees


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With a new web-based platform, users can see hot day projections for many U.S. cities and towns. (Climate Central)
Jenna Ladd| August 18, 2017

By now it’s common knowledge that as greenhouse gases continue to accumulate in our atmosphere, intensely high temperatures are likely to occur more frequently.

But Climate Central, a climate research and news organization, has developed a way for residents of the continental U.S. to see exactly how much their communities will be affected. The interactive tool allows users to type in the name of their city or town and view the average number of days that will exceed specific temperature thresholds in 2050, 2075 and 2100.

The analysis includes data for nearly 30,000 cities and towns of various sizes from across the continental U.S. Each graph provides two possible outcomes: one in which greenhouse gas emissions continue as usual and one in which they are moderately curtailed.

Researchers based their projections on aggregated data from 21 global climate models.

At present, Des Moines experiences an average of zero days per year when the actual temperature is above 100 degrees Fahrenheit. According to this study, the city will likely see 15 days annually that exceed the temperature threshold in 2050 and up to 30 per year in 2100.

This year is on track to be the hottest year ever, followed by 2016, 2015, and 2014, respectively.

Lyme disease more common due to climate change


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Deer ticks thrive in hot and humid forested areas. (flickr/Joslyn Gallant)
Jenna Ladd| August 17, 2017

As temperatures and humidity rise in the United States, conditions are becoming more favorable for disease-carrying deer ticks.

The U.S. Environmental Protection Agency (EPA) reports that climate change has expanded the geographical range of ticks. Deer ticks specifically are most active when temperatures are above 45 degrees Fahrenheit and humidity is at least 85 percent. As temperatures and humidity rise in many parts of North America, so too are tick populations. The EPA reports that the incidence of Lyme disease in the U.S. has doubled since 1991.

The Northeastern U.S. has experienced the sharpest increase Lyme disease transmission. This part of the country is becoming more humid, making conditions better for ticks to emerge from the ground and latch onto hosts. New Hampshire, Maine, and Vermont have seen the largest spike in Lyme disease incidence since 1991, followed closely by Delaware and Massachusetts. On average, the EPA reports, these states now see 50 to 100 more cases per 100,000 people than they did in 1991.

In the future, deer tick populations are expected to double in the U.S. and become up to five times more numerous in Canada.

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Incidence of Lyme disease per 100,000 people. (EPA)

New study assesses flood risks for schools nationwide


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The impact of flooding on schools is often compounded by aging infrastructure, according to a recent study. (FEMA)
Jenna Ladd| August 8, 2017

A recent study by the Pew Charitable Trusts generated flood risk scores for 84,123 primary and secondary schools nationwide.

The report’s authors pointed out that flooding is the most costly and common natural disaster, affecting every region of the U.S. Many times, severe floods badly damage schools, causing them to close. For example, the study points out, floods in West Virginia in June 2016 cost $130 million in damage to regional schools.

Researchers used three metrics to generate county-wide composite flood risk vulnerability scores for schools in all fifty states including: a school’s location within a designated flood zone, the percentage of a school’s neighborhood (as represented by ZIP code) located within a flood zone, and the number of historical flood-related federal disaster declarations in that county.

Among the study’s major findings are that flood risk is distributed across diverse regions of the country. Schools with the highest flood risk scores were located in the Atlantic Coast, Gulf Coast, Mississippi River corridor, and southwestern Arizona. Similarly, those schools with the highest composite flood risk scores were located in both coastal and inland regions. Those 100 counties with the highest composite flood risk scores include 6,444 schools that serve almost 4 million students.

The study made some recommendations for steps policymakers can take to increase flood resiliency for schools. They included generating up-to-date local flood maps, developing pre-disaster flood plans for schools, working to leverage federal assistance, and relocating schools out of floodplains if possible.

The Pew Charitable Trusts full analysis can be found here.

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The highest flood risk areas are scattered across many regions of the country. (Pew Charitable Trusts)

Climate change likely to cause surge in nutrient runoff


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A small portion of a hypoxic dead zone in the Chesapeake Bay. (Chesapeake Bay Program)
Jenna Ladd| August 4, 2017

A recent study found that increased precipitation due to climate change will lead to markedly increased nutrient runoff.

Nitrogen rich fertilizers are widely used by U.S. farmers. Many times, more fertilizer than crops can use are applied to the land and the excess runs off into local waterways, eventually draining into the ocean. Excessive nutrient enrichment, also known as eutrophication, decreases available oxygen in the water and kills off aquatic species, resulting in “dead zones.”

Warmer temperatures associated with climate change are expected to continue producing heavier rainfall, thereby increasing nutrient runoff by up to twenty percent by 2100. Anna Michalak, a professor of global ecology at the Carnegie Institution for Science at Stanford and one of the authors of the study, told the New York Times, “When we think about climate change, we are used to thinking about water quantity — drought, flooding, extreme rainfall and things along those lines. Climate change is just as tightly linked to issues related to water quality, and it’s not enough for the water to just be there, it has to be sustainable.”

Researchers concluded that the Upper Mississippi Atchafalaya River Basin, the Northeast and the Great Lakes basin are likely to see the largest increases in nutrient runoff because these areas of the country are already creating hypoxic dead zones. Climate change will likely compound these effects.

While the study focused on the continental U.S., the researchers did apply their model to parts of the world most similar to it. They found that large areas of East, South and Southeast Asia will likely see nutrient runoff surges similar to those in the U.S. Given that some people in these regions depend on surface water to survive, the impacts of nutrient pollution there may be especially lethal.

On The Radio – PCB sources located in schools


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Researchers found concentrations of PCBs to be higher indoors regardless of the school’s location. (Gordon Lew/flickr)
Jenna Ladd| July 31, 2017

This week’s On The Radio segment discusses a recent University of Iowa study which revealed that dated building materials in schools release PCBs into the air.

Transcript: In the largest study of its kind, UI Researchers recently made important discoveries related to the presence of polychlorinated biphenyls, or PCBs, in schools.

This is the Iowa Environmental Focus.

Led by the Iowa Superfund Research Program, the study tested indoor and outdoor air samples from six schools for PCBs. PCBs are a class of manmade organic chemicals known to cause cancer as well as immune, endocrine and reproductive system problems in humans.

The study found that regardless of the school’s location, from Columbus Junction in rural Iowa to heavy industrial areas of East Chicago, concentrations of PCBs were higher indoors. PCBs were commonly used in construction and manufacturing through 1979. The research article, published in the journal Environmental Science & Technology, points to old window caulking and light ballasts as likely sources of PCBs in schools.

Research has shown that exposure to PCBs during childhood can cause significant neurological deficits, visual impairment and learning difficulties. Schools in the U.S. are not currently required to measure PCB concentrations.

For more information or to read the full study, visit iowa-environmental-focus-dot-org.

From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.

Researchers use climate data to predict Zika outbreaks


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The Aedes aegypti mosquito transmits many diseases including Zika. (Sanofi Pasteur/flickr)
Jenna Ladd| July 25, 2017

Zika virus spread rampantly throughout the Americas in 2014 and 2015. While the infection itself presents with few noticeable symptoms, it has been linked to an increased number of babies born with microcephaly and Guillain-Barré syndrome, which can result in paralysis.

So far, there have been 5,932 cases of the virus reported in the U.S. and nearly 40,000 in U.S. territories such as Puerto Rico. Zika is transmitted by the Aedes mosquito and human sexual contact.

In a study published recently in the journal Frontiers in Microbiology, researchers developed a way to predict Zika outbreaks before they happen. The scientists used climate data from Zika-prone areas to build computer models for Aedes mosquito populations.

One of the study’s authors, Dr. Ángel Muñoz of Princeton University, said, “Both the mosquitos that transmit Zika and the virus itself are climate-sensitive.” He continued in an interview with E & E news, “High temperatures, like the ones observed during the record-breaking years 2015 and 2016, generally increase the virus replication rates and also the speed of mosquito reproduction. The overall effect of high temperatures is an increase in the potential risk of transmission.”

The researchers used their computer model to test how well their projections of the virus spreading matched with what actually occurred in 2014 and 2015. They found that their model could consistently predict a Zika outbreak one month before it occurred. In some areas, the model predicted an epidemic three months in advance.

Their computer model is not without its limitations. First, the study notes that scientists can only confidently make predictions for entire countries and regions, not cities or towns. Second, Aedes mosquitos also carry dengue and chikungunya, so the model does not distinguish whether the mosquitos are carrying Zika or another vector-borne disease. It simply indicates when conditions for disease transmission are highly suitable.

Dr. Benjamin Beard is deputy director of the Centers for Disease Control and Prevention’s Division of Vector-Borne Diseases. Referring to the changing climate and increased international travel, he said in an email, “We are seeing an accelerated threat from mosquito-borne diseases overall. Over the past few decades, we have seen a resurgence of dengue and the introduction of West Nile, chikungunya, and now Zika virus into the Western Hemisphere.”

On The Radio – Urban areas to suffer economic costs of climate change


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According to a recent study, the world’s larger cities, such as New York City, will be hit hardest by global warming. (Chris Goldberg/flickr)
Jenna Ladd| July 24, 2017

This week’s On The Radio segment describes how climate change will have a disproportionate economic impact on urban areas.

Transcript: A recent study by an international group of economists found that climate change will likely cost cities twice as much as rural areas.

This is the Iowa Environmental Focus.

The study, published in the journal Nature Climate Change, found that the largest quarter of the world’s cities could see more intense temperature spikes by 2050 due to the combined effect of global warming and urban heat island effects. Urban heat islands are formed when naturally cooling surfaces like vegetation and bodies of water are replaced by surfaces that trap heat like concrete and asphalt.

Higher temperatures in cities have negative economic impacts including less productive workers, higher cooling costs for buildings and poorer water and air quality. On average, the global gross domestic product (GDP) is expected to drop by 5.6 percent by 2100 due to climate change. The combined climate change and heat island effect means that the most-impacted cities are expected to lose about 11 percent of their GDP in the same period.

The economists noted that some actions can be taken to mitigate these effects including installing cooling pavements and green roofs and reintroducing vegetation in urban areas.

To read the full story and for more information, visit iowa-environmental-focus-dot-org.

From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.