Allergy Season

Climate Change & Allergies


William Anderegg

With spring around the corner, here's some bad news for allergy sufferers: Human-caused climate change has both worsened and lengthened pollen seasons across the U.S. and Canada, a study Monday reports.

The new research shows that pollen seasons start 20 days earlier, are 10 days longer and feature 21% more pollen than they did in 1990.

“The strong link between warmer weather and pollen seasons provides a crystal-clear example of how climate change is already affecting people's health across the U.S.,” said study lead author William Anderegg, a biologist at the University of Utah.

"Climate change is making pollen seasons worse across the U.S., and that has major implications for asthma, allergies and other respiratory health problems," he told USA TODAY.

Climate change, aka global warming, is caused by the burning of fossil fuels such as oil, gas and coal, which release greenhouse gases such as carbon dioxide and methane into the atmosphere.

Allergies to airborne pollen can be more than just a seasonal nuisance to many. Allergies are tied to respiratory health and have implications for viral infections, emergency room visits and even children’s school performance, according to a statement from the University of Utah. More pollen, hanging around for a longer season, makes those impacts worse.

Climate change has two broad effects, according to the study. First, it shifts pollen seasons earlier and lengthens their duration. Second, it increases the pollen concentrations in the air so pollen seasons are, on average, worse.

Anderegg's research team looked at measurements from 1990 to 2018 from 60 pollen count stations across the U.S. and Canada, maintained by the National Allergy Bureau.

Although nationwide pollen amounts increased by around 21% over the study period, the greatest increases were recorded in Texas and the Midwest, and more among tree pollen than among other plants.

"Our findings are consistent with a broad body of research on pollen seasons, respiratory health and climate change," Anderegg said. "Other studies have also found increasing pollen loads in many regions and, in controlled greenhouse settings, that warmer temperatures and higher carbon-dioxide concentrations increase plant pollen production."

The researchers also found that the contribution of climate change to increasing pollen amounts is accelerating.

“Climate change isn’t something far away and in the future," Anderegg concluded. "It’s already here in every spring breath we take and increasing human misery. The biggest question is – are we up to the challenge of tackling it?”

The study was published in the Proceedings of the National Academy of Sciences, a peer-reviewed journal.

 

First published @ usatoday

Forest Futures

Forest Futures


Know the risks of investing in forests.

Given the tremendous ability of forests to absorb carbon dioxide from the atmosphere, some governments are counting on planted forests as offsets for greenhouse gas emissions—a sort of climate investment. But as with any investment, it’s important to understand the risks. If a forest goes bust, researchers say, much of that stored carbon could go up in smoke.

In a paper published in Science, University of Utah biologist William Anderegg and his colleagues say that forests can be best deployed in the fight against climate change with a proper understanding of the risks to that forest that climate change itself imposes. “As long as this is done wisely and based on the best available science, that’s fantastic,” Anderegg says. “But there hasn’t been adequate attention to the risks of climate change to forests right now.”

Meeting of Minds

William Anderegg

In 2019, Anderegg, a recipient of the Packard Fellowship for Science and Engineering from the David and Lucile Packard Foundation, convened a workshop in Salt Lake City to gather some of the foremost experts on climate change risks to forests. The diverse group represented various disciplines: law, economics, science and public policy, among others. “This was designed to bring some of the people who had thought about this the most together and to start talking and come up with a roadmap,” Anderegg says.

This paper, part of that roadmap, calls attention to the risks forests face from myriad consequences of rising global temperatures, including fire, drought, insect damage and human disturbance—a call to action, Anderegg says, to bridge the divide between the data and models produced by scientists and the actions taken by policymakers.

Accumulating Risk

Forests absorb a significant amount of the carbon dioxide that’s emitted into the atmosphere—just under a third, Anderegg says. “And this sponge for CO2 is incredibly valuable to us.”

Because of this, governments in many countries are looking to “forest-based natural climate solutions” that include preventing deforestation, managing natural forests and reforesting. Forests could be some of the more cost-effective climate mitigation strategies, with co-benefits for biodiversity, conservation and local communities.

But built into this strategy is the idea that forests are able to store carbon relatively “permanently”, or on the time scales of 50 to 100 years—or longer. Such permanence is not always a given. “There’s a very real chance that many of those forest projects could go up in flames or to bugs or drought stress or hurricanes in the coming decades,” Anderegg says.

Forests have long been vulnerable to all of those factors, and have been able to recover from them when they are episodic or come one at a time. But the risks connected with climate change, including drought and fire, increase over time. Multiple threats at once, or insufficient time for forests to recover from those threats, can kill the trees, release the carbon, and undermine the entire premise of forest-based natural climate solutions.

“Without good science to tell us what those risks are,” Anderegg says, “we’re flying blind and not making the best policy decisions.”

Mitigating Risk

In the paper, Anderegg and his colleagues encourage scientists to focus increased attention on assessing forest climate risks and share the best of their data and predictive models with policymakers so that climate strategies including forests can have the best long-term impact. For example, he says, the climate risk computer models scientists use are detailed and cutting-edge, but aren’t widely used outside the scientific community. So, policy decisions can rely on science that may be decades old.

“There are at least two key things you can do with this information,” Anderegg says. The first is to optimize investment in forests and minimize risks. “Science can guide and inform where we ought to be investing to achieve different climate aims and avoid risks.”

The second, he says, is to mitigate risks through forest management. “If we’re worried about fire as a major risk in a certain area, we can start to think about what are the management tools that make a forest more resilient to that disturbance.” More research, he says, is needed in this field, and he and his colleagues plan to work toward answering those questions.

“We view this paper as an urgent call to both policymakers and the scientific community,” Anderegg says, “to study this more, and improve in sharing tools and information across different groups.” Read the full paper @ sciencemag.org

 

 

by Paul Gabrielsen first published in @theU