HEAT.gov — National Integrated Heat Health Information System

Heat related illnesses and death are largely preventable with proper planning, education, and action. Heat.gov serves as the premier source of heat and health information for the nation to reduce the health, economic, and infrastructural impacts of extreme heat.

Webinar: Implementing Renewable Energy in Industrial Facilities

Aug 2, 2022, 10am CDT
Register here.

From solar to wind and geothermal to hydro, the world of renewable energy options can be hard to navigate. Through Better Plants, DOE has developed a guidance document on renewable energy for industry. Learn the basics of different renewable technologies, find out how you can obtain renewable power for your organization, and discover tools and resources that can help you evaluate renewable energy systems.

Midwest forests lost 8,000 years of stored carbon in just 150 years – new animated maps track the changes, revealing lessons for climate projects today

Living trees, like these near Traverse City, Michigan, remove carbon dioxide from the air and lock it away. Owen Weber/www.owenweberlive.com via Getty Images

by Jason McLachlan, University of Notre Dame

“Plant a tree” seems to be the go-to answer to climate change concerns these days. Booking a rental car online recently, I was asked to check a box to plant a tree to offset my car’s anticipated carbon dioxide emissions. In 2020, the governor of my state, Indiana, launched an initiative to plant a million of them within five years, and the state is a quarter of the way there.

The primary reason for this arboreal zeal is to capitalize on the power of trees to remove excess carbon dioxide from the atmosphere and turn it into wood, safely locking carbon away for decades to centuries.

That’s the theory, anyway.

The problem is that the fate of carbon stored in trees faces many challenges. Heat waves, logging, pests and wildfires can all destroy trees and release that carbon again. And most measurements of the carbon stored in forests’ woody biomass only extend back a few decades.

I lead the PalEON project, an initiative funded by the National Science Foundation that is working to reconstruct how the amount of carbon stored in U.S. trees ebbed and flowed over the past 10,000 years.

Loggers in 1900 cut down trees in what is now Michigan’s Huron-Manistee National Forests. Forest Service

Our new reconstruction reveals in detail how forests in the upper Midwest gained almost a billion tons of carbon over the last 8,000 years, doubling their carbon storage. And then, in the span of just 150 years, almost all of that gain disappeared into the atmosphere.

The results offer lessons for today, particularly about the outsized role that a few tree species, human behavior and a changing climate can play.

How forests gained, then lost, a billion tons of carbon

Our forest story starts 10,000 years ago, after the massive Laurentide ice sheet that once covered a large portion of North America retreated from the upper Midwest – what is now Michigan, Wisconsin, Minnesota and the northern edges of Illinois and Indiana. In this early period of natural warming, ice-age forests of needle-leaved trees shrank and were replaced by new tree species slowly spreading northward from southern refuges.

Forest growth rose and fell over the thousands of years that followed as the climate went through warm and cool periods, the frequency and intensity of wildfires changed, and Native American land management strategies shifted.

Carbon storage changes over time: through 1850, in megagrams, or metric tons, per hectare. PalEON Project

Previous studies assumed that the amount of woody biomass – the carbon stored in trees – had been relatively stable over millennia before the industrial era. Instead, we were surprised to find that the Upper Midwest forests had steadily gained carbon for 8,000 years before Euro-American settlers began clearing large swaths of forest.

In much of the region, forests had become dominated by long-lived species that could store a lot of carbon as biomass. Two of those species stand out: American beech and eastern hemlock.

History in a grain of pollen

We know a lot of this thanks to tiny grains of ancient pollen and the Public Land Survey, a collection of highly detailed forest surveys conducted by government contractors in the mid-1800s, shortly before forest clearing took off.

Each year, trees release pollen, and some of that pollen falls into lakes, where it sinks into the mud and fossilizes. Scientists can study fossilized pollen in cross sections of lake bottom sediment to determine how old it is and the types of trees that were growing at the time. If a major fire came through, abrupt changes in the types of pollen in the sediment would give it away.

Maps show hemlock and beech spreading northward and the western transition zone between forest and grasslands shifting over time.
How two tree species that sequester a lot of carbon migrated in the Upper Midwest, and the changing line between forests and grasslands in the western part of the region. PalEON Project, CC BY-ND

In a study recently published in the journal Science, Ann Raiho and other PalEON members mapped biomass changes in the Upper Midwest using a sophisticated statistical model based on the fossil pollen found in the sediment from a network of lakes. The Public Land Survey served as a sort of Rosetta Stone. The survey linked vegetation in the 1800s to the fossil pollen samples, allowing us to calibrate pollen levels with the amount of wood biomass.

Lessons from 10,000 years of forest growth and decline

Our maps of past biomass accumulation provide reason for optimism about the capacity of forests to sustainably store carbon for long periods, but also two warnings.

The optimistic take is that when forests dominated by old-growth species like American beech and eastern hemlock expanded, the forests stored large amounts of carbon in woody biomass for millennia. These two species contributed substantial carbon storage, particularly in the moister central and eastern parts of the region.

American beech trees in a forest. Nicholas T/flickr, CC BY

The first warning is that forests in the drier western part of our study area shrank when the climate became warmer and drier.

The second warning is that progress can quickly slip away. Although the Upper Midwest forests stored almost a billion tons more carbon than they lost over the last 8,000 years, that accumulation went back into the atmosphere over a short period of time as a result of logging and farming. We found the rate of woody biomass decline over the last 150 years was 10 times greater than in any other century in 10,000 years.

Looking ahead

So, what does this mean for tree planting efforts today?

If my rental car tree happened to be an American beech, and if it were allowed to mature and propagate an old-growth forest in the Upper Midwest, then future forests could replicate the processes that stored carbon for thousands of years.

But that future presumes that drought, pests and wildfires associated with a rapidly warming climate don’t undo those efforts. A recent study suggested that forests around the world may be losing resilience to climate warming.

The capacity of old-growth trees to store carbon can also be undone by other threats that can be exacerbated by the changing climate. For example, beech bark disease weakens trees, allowing fungus to kill them – and it’s now threatening the Upper Midwest’s beech populations.

Map shows where the US has tree cover today, largely in the East and mountains.
U.S. forest cover today. Trees were larger and forests more extensive thousands of years ago. Robert Simmon/NASA Earth Observatory

Finally, communities will have to balance the value of carbon sequestered in old forests with other priorities.

From a conservation perspective, both the high-biomass, old-growth beech and hemlock forests and the lower-biomass oak savannas were important components of Midwestern vegetation over the last 10,000 years. However, open oak forests are now endangered, and the practices needed for their recovery, like controlled burns, are designed to keep competing species at bay – including American beech.

The past offers guidance for managing forest change in the future, but not easy answers.

Jason McLachlan, Associate Professor of Paleoecology, University of Notre Dame

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Webinar: EPA PFAS Strategic Roadmap: Research Tools and Resources

Aug 17, 2022, 2 pm CDT
Register here.

This webinar will provide a brief overview of EPA’s PFAS Strategic Roadmap and ongoing efforts by EPA’s Office of Research and Development (ORD) to address key PFAS research needs for environmental decision-making. ORD scientists will highlight two recently released data sources: EPA’s PFAS Thermal Treatment Database, which contains information on the treatability of PFAS via various thermal processes, and Systematic Evidence Maps for PFAS, which summarize available toxicity evidence for approximately 150 different PFAS. Recent updates to other PFAS resources will also be shared.   

Justice Dept. will investigate environmental racism in Houston

Read the full story in the New York Times.

The inquiry, part of an administration-wide racial justice initiative, came amid claims that the city has ignored illegal dumping in Black and Latino areas.

Extreme heat is here. Here’s how we create a heat-resilient nation.

Read the full story at Smart Cities Dive.

In the face of worsening climate change, helping communities manage heat effects will require cooperation among local, state and federal governments, one researcher writes.

Can supply chain and procurement professionals spearhead sustainability in the manufacturing sector?

Read the full story at The Manufacturer.

Across the world, manufacturers of everything, from cupboards to computers, have been grappling with monumental supply chain challenges, stemming from geopolitical instability, the COVID-19 pandemic and related goods shortages. And yet, there is a bigger problem that manufacturers are simultaneously facing: sustainability.

PFAS are toxic and they’re everywhere. Here’s how to stay away from them.

Read the full story in Popular Science.

It might be impossible to eliminate them completely, but you can certainly reduce your exposure.

Western solar boom threatens wildlife’s home on the range

Read the full story at E&E News.

It was not long after Wyoming’s first large-scale solar project came online in 2019 that the antelopes made themselves known.

More than 1,000 pronghorns — the “American antelope” — galloped onto Wyoming’s Highway 372 that winter, terrifying drivers and biologists alike. The animals would typically migrate over public land, but with the 700-acre Sweetwater Solar farm blocking their way, they took the highway.

State officials are working now to make sure that doesn’t happen again as energy developers eye wide-open swaths of land for utility-scale solar projects. Angi Bruce, deputy director of the Wyoming Game and Fish Department, said that while the state fosters energy development, it also prioritizes “making sure our wildlife thrives because we value it so highly here.”

Improving science literacy means changing science education

Introductory science classes typically require students to memorize facts, rather than teaching them the basis of scientific thinking. Maskot via Getty Images

by Zahilyn D. Roche Allred, Florida International University

To graduate with a science major, college students must complete between 40 and 60 credit hours of science coursework. That means spending around 2,500 hours in the classroom throughout their undergraduate career.

However, research has shown that despite all that effort, most college science courses give students only a fragmented understanding of fundamental scientific concepts. The teaching method reinforces memorization of isolated facts, proceeding from one textbook chapter to the next without necessarily making connections between them, instead of learning how to use the information and connect those facts meaningfully.

The ability to make these connections is important beyond the classroom as well, because it’s the basis of science literacy: the ability to use scientific knowledge to accurately evaluate information and make decisions based on evidence.

As a chemistry education researcher, I have been working since 2019 with my colleague Sonia Underwood to learn more about how chemistry students integrate and apply their knowledge to other scientific disciplines.

In our most recent study, we investigated how well college students could use their chemistry knowledge to explain real-world biological phenomena. We did this by having them do activities designed to make those cross-disciplinary connections.

We found that even though most of the students had not been given similar opportunities that would prepare them to make those links, activities like these can help – if they are made part of the curriculum.

Three-dimensional learning

A large body of research shows that traditional science education, for both science majors and non-majors, doesn’t do a good job of teaching science students how to apply their scientific knowledge and explain things that they may not have learned about directly.

With that in mind, we developed a series of cross-disciplinary activities guided by a framework called “three-dimensional learning.”

In short, three-dimensional learning, known as 3DL, emphasizes that the teaching, learning and assessing of college students should involve the use of fundamental ideas within a discipline. It should also involve tools and rules that support students in making connections within and between disciplines. Finally, it should engage students in the use of their knowledge. The framework was developed on the basis of how people learn as a way to help all students gain a deep understanding of science.

We did this in collaboration with Rebecca L. Matz, an expert in science, technology, engineering and math education. Then we took these activities to the classroom.

Making scientific connections

To begin, we interviewed 28 first-year college students majoring in the sciences or engineering. All were enrolled in both introductory chemistry and biology courses. We asked them to identify connections between the content of these courses and what they believed to be the take-home messages from each course.

The students responded with extensive lists of topics, concepts and skills that they’d learned in class. Some, but not all, correctly identified the core ideas of each science. They understood that their chemistry knowledge was essential to their understanding of biology, but not that the reverse might be true as well.

For example, students talked about how their knowledge gained in their chemistry course regarding interactions – that is, attractive and repulsive forces – was important to understand how and why the chemical species that make up DNA come together.

For their biology course, on the other hand, the core idea that the students spoke of most was the structure-function relationship – how the shape of the chemical and biological species determine their job.

Next, a set of cross-disciplinary activities were designed to guide students in the use of chemistry core ideas and knowledge to help explain real-world biological phenomena.

The students reviewed a core chemistry idea and used that knowledge to explain a familiar chemistry scenario. Next, they applied it to explaining a biological scenario.

One activity explored the the impacts of ocean acidification on sea shells. Here, the students were asked to use basic chemistry ideas to explain how increasing levels of carbon dioxide in seawater are affecting shell-building marine animals such as corals, clams and oysters.

Other activities asked the students to apply chemistry knowledge to explaining osmosis – how water transfers in and out of cells in the human body – or how temperature can alter the stability of human DNA.

Overall, the students felt confident in their chemistry knowledge and could easily explain the chemistry scenarios. They had a harder time applying the same chemistry knowledge to explaining the biological scenarios.

In the ocean acidification activity, the majority of the students were able to accurately predict how an increase in carbon dioxide affects the acidic levels of the ocean. However, they weren’t always able to explain how these changes affect marine life by hampering the formation of shells.

These findings highlight that a big gap remains between what students learn in their science courses and how well prepared they are to apply that information. This problem remains despite the fact that in 2012, the National Science Foundation put out a set of three-dimensional learning guidelines to help educators make science education more effective.

However, the students in our study also reported that these activities helped them see links between the two disciplines that they wouldn’t have perceived otherwise.

So we also came away with evidence that our chemistry students, at least, would like to have the ability to gain a deeper understanding of science, and how to apply it.

Zahilyn D. Roche Allred, Postdoctoral Scholar, Department of Chemistry and Biochemistry, Florida International University

This article is republished from The Conversation under a Creative Commons license. Read the original article.