“Frost-free” days increase, so does allergy season


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Climate Central’s graph illustrates how the number of frost-free days in Des Moines has increased over time. (Climate Central)
Jenna Ladd | April 11, 2018

Given that spring snow fell across Iowa this weekend, it may be hard to believe that the frost-free season across the U.S. is actually getting longer.

A recent report found that, on average, the last spring freeze is occurring earlier while the first fall freeze is happening later. Researchers define the frost-free season as the total number of days between the last day of 32 degree Fahrenheit or lower weather in the spring and the first day of 32 degree Fahrenheit weather in the fall.

The lengthening of this season means that pollen-producing plants have a longer growing period. One study in particular found that the growing season for ragweed, a common allergen in the U.S., lengthened by two to four weeks between 1995 and 2009. This data was collected from ten sites from the southern U.S. through Canada. Iowa has added nine days to the average length of its frost-free season from 1986-2015 when compared with the average from 1901-1960.

Not only are allergy-causing plants benefiting from longer growing seasons, but an uptick in atmospheric carbon dioxide also increases pollen counts. Last year was the worst allergy season in recent record and experts expect this year to be similar.

Dr. Joseph Shapiro, an allergist and immunologist from California told CBS news, “A recent study showed that pollen counts are likely to double by the year 2040, so in a little more than 20 years we’re going to see a significant increase [in seasonal allergies].”

Climate Central’s recent report provides an interactive graph that allows users to select a U.S. city and see how the frost-free season’s length there may have changed since 1970.

German court gives cities authority to ban diesel vehicles


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Munich is one of the German cities that routinely exceeds European Union NOx emission limits. (Vladimer Shioshvili/flickr)
Jenna Ladd | March 1, 2017

Germany’s federal court ruled on Tuesday that cities can ban diesel vehicles in order to lower air pollution.

Environmental Action Germany has been filing lawsuits against cities for years to encourage municipalities to implement policies that curb air pollution. German government statistics reveal that some 6,000 people die each year from nitrogen oxide pollution, 60 percent of which comes from vehicles on the road. Diesel engines in particular spew more NOx than gasoline engines and are more popular in Europe.

The ruling does not require communities to ban diesel driving, rather it grants them the legal authority to do so if air pollution in their city remains above the European Union limit for NOx in the air. Seventy German cities surpassed that threshold at least once last year.

Banning diesel vehicles would have negative implications for the country’s automotive industry. Since the ruling, the German government has proposed some measures to decrease pollution and avoid the ban, which include providing free public transportation and refitting existing diesel vehicles to meet clean air standards. However, it is unclear how the government would pay for such measures.

Germany is merely the latest country making a move away from diesel engines. Paris, Madrid, Mexico City and Athens have policies in place to ban diesel vehicles from city centers before 2025.

Climate change alters forest composition


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Sugar maples are seeing population decreases across the U.S. due to climate change, making fiery autumn leaves harder to find. (Mark K./flickr)
Jenna Ladd | February 28, 2017

Beech trees are crowding out other important tree species in northeastern United States woodlands because of climate change, according to a recent study.

Researchers from the University of Maine tracked beech, sugar and red maple tree data in the northeastern U.S. from 1983 to 2014. The U.S. Forest Service data showed that beech tree populations have increased significantly over the thirty years while the other tree species decreased. The study found that hotter temperatures and increased precipitation, both caused my climate change, allowed for beech trees’ population boom.

Beech trees have important advantages over the species that used to dominate the area. First, they often shade out other species competing for sunlight. Second, the local deer prefer the taste of sugar and red maple saplings to beech ones. The changing climate is changing the composition of forests and managers will have to adapt, researchers say.

Dr. Aaron Weiskittel is a forest biometrics and modeling professor at University of Maine and one of the study’s authors. “There’s no easy answer to this one,” he said to the Associated Press, “It has a lot of people scratching their heads. Future conditions seem to be favoring the beech, and managers are going to have to find a good solution to fix it.”

Sugar maples, one of the important species declining in the northeastern U.S., are also expected to decline in numbers in the northern Midwest due to climate change. A twenty-year study published in January found that as global temperatures continue to rise, sugar maple growth in the northern Midwest will be stunted and the species population will decrease.

Researchers point out that forests soak up 25 percent of the greenhouse gases that are emitted each year, so continuing to learn about how forests will respond to the changing climate should be prioritized.

Extreme weather events more likely even if climate change is curtailed


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Parched soil in Illinois during the 2012 drought. (Thought Quotient/flickr)
Jenna Ladd | February 22, 2017

A study recently published in the journal Science Advances found that even if global climate change mitigation goals are met, extreme weather events will still occur more frequently in the future.

The United Nations Paris Climate Accord aims to keep global temperatures from increasing more than two degrees Celsius above pre-industrial levels. Even if the global community succeeds, human-induced climate change has already made extreme heatwaves, floods and droughts significantly more common.

Unfortunately, scientists say that the existing emission-reduction pledges by the world’s nations are not enough to keep temperatures from rising above 2 degrees Celsius. The study finds that if temperatures were to rise to 3 degrees hotter than preindustrial levels, North America would see at least a 300 percent increase in extreme weather events, for example.

Dr. Noah Diffenbaugh is a climate scientist at Stanford University and the study’s lead author. He said to the Scientific American, “In addition to not meeting the global temperature target, those commitments also imply substantial increase in the probability of record-setting events. Not only hot events but wet events, and also in other regions of the world, dry events as well.”

The study found that extreme heat records are the most likely to be affected by unabated climate change. Scientists focused primarily on North America, Western Europe and East Asia. They found that hotter-than-ever night time temperatures have been occurring much more frequently in recent years. If the climate warms to the 3 degree threshold, extreme heat events are expected to happen five times more frequently in half of Europe and at least three times more frequently in parts of Eastern Asia.

The study reads, “However, even if cumulative emissions are sufficiently constrained to ensure that global warming is held to 1° to 2°C, many areas are still likely to experience substantial increases in the probability of unprecedented [extreme weather] events.”

An interactive map created by researchers at Carbon Brief allows user to see which past extreme weather events can were cause by anthropogenic climate change and which were not.

Plea for Iowa to join U.S. Climate Alliance


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An Iowa wind farm extends as far as the eye can see. (News/flickr)

Jenna Ladd | February 16, 2018

President Trump decided to remove the United States from the Paris Climate Accord in September, and since then numerous U.S. governors have expressed their desire to stay in the treaty through the U.S. Climate Alliance.

The bi-partisan Climate Alliance is “committed to reducing greenhouse gas emissions consistent with the goals of the Paris Climate Agreement.” Its members represent 40 percent of the total U.S. population and at least $7.4 trillion dollars in U.S. gross domestic product. Sixteen governors are members of the alliance currently, and a democrat in the Iowa House of Representatives is hoping to add Governor Reynolds to that list. Representative Charles Isenhart of Dubuque presented a letter to the Iowa Energy Center on Monday, asking that Iowa join the alliance. Isenhart also proposed a bill in the House of Representatives that would require Iowa’s membership in the U.S. Climate Alliance.

Isenhart said to The Register,“We’ve already done a lot and are doing a lot and have some of the mechanisms in place to do more. We should be joining if for no other reason than to take credit for what we’ve already done.” The state of Iowa leads the nation in wind energy production, and is expected to generate more than forty percent of its energy from the wind by 2020.

Julie Cerqueira is executive director of the U.S. Climate Alliance. She said in a letter,

“As I read the Iowa Energy Plan, it is clear that many of the state’s energy priorities align with the priorities of the Alliance — a focus on innovation, workforce development, modernizing our electrical grids and promoting the expansion of electric vehicles. Furthermore, Iowa’s long history of leadership in clean energy, in particular the successful deployment of wind power at scale, makes its membership in the U.S. Climate Alliance both logical and valuable.”

A spokesperson for Governor Reynolds says that the governor has not yet considered joining the U.S. Climate Alliance.

 

 

Simple way to recycle methane discovered


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Methane flaring from a hydraulic fracking well in Pennsylvania. (WCN/flickr)

Jenna Ladd | February 9, 2018

Scientists have recently discovered a way to simply convert excess methane into the building blocks for plastics, agrochemicals and pharmaceuticals.

A study funded by the Department of Energy by researchers at the University of Southern California has identified a one-step chemical process to change methane into basic chemicals ethylene and propylene. Methane is known to be 86 times more potent than carbon dioxide, especially in terms of short-term greenhouse gas effects. The gas’ sources include hydraulic fracking wells, organic matter breaking down in landfills or large livestock operations.

The U.S. produces more methane than almost any other country, but the new research presents an opportunity to trap and use the gas. Currently, methane must be shipped via large pipelines from release points to processing areas in order to be converted into anything useful. The study’s authors point out that this practice is cost-prohibitive for many producers, but their research offers a solution. The one-step process means that methane can be captured on-site and transformed into ethylene and propylene without costly transportation.

U.S. Environmental Protection Agency Administrator Scott Pruitt, who sued the agency several times before becoming its leader, has spoken about the potency of methane as a greenhouse gas in recent public addresses. He claims the agency will work to address the issue, but government spending plans say otherwise. A 2019 federal budget plan proposes a 72 percent funding cut for the Department of Energy renewable energy and energy efficiency program, the very same program that funded this study.

Coal plants closing at unprecedented rate


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A coal plant spews pollutants on the Navajo reservation near Page, Arizona. (Photo Kent/flickr)

Jenna Ladd | February 2, 2018

Coal’s role in the U.S. energy picture is rapidly shrinking according to a report from the independent, non-profit Union of Concerned Scientists.

From 2008 to 2016, the portion of the U.S.’s energy derived from coal decreased from 51 percent to 31 percent. Of those coal units that are still up and running, about 25 percent of them plan to retire or switch to another energy source soon. While some coal units are retiring completely, many of them are switching to natural gas. Either way, the report found that the decreased coal production has provided the following environmental health benefits:

  • 80 percent less sulfur dioxide, a source of acid rain
  • 64 percent less nitrogen oxide, a key component in smog
  • 34 percent less carbon dioxide, a heat-trapping gas

Scientists estimate these changes have saved residents about $250 billion in public health costs related to breathing polluted air from 2008 to 2016.

The driving force behind coal’s decline is primarily economic. Natural gas is cheaper than the dirty fuel, and new research found that newly constructed wind and solar plants are more cost effective than new coal plants.

The researchers also looked at the challenges faced by economies in former coal-mining areas to learn more about how residents cope with closing plants. The results were decidedly mixed. For example, after one especially dirty plant in Chicago closed down following years of activism, area residents found that the city planned to redevelop the building into a transportation center–posing additional air quality risks. In contrast, an organization in West Virginia is working to train laid off coal-workers in construction, agriculture and solar energy jobs. As the shift to cleaner energy sources continues, the Union of Concerned Scientists call on lawmakers. They write,

“As more coal plants close, the importance of investing in these and other impacted communities will only grow. Policy makers should prioritize economic development and job transition assistance, alongside other investments in renewable energy and energy efficiency.”