Category: agriculture

Eastern U.S. most vulnerable to future harmful algal blooms

New modeling shows where global warming will increase cyanobacteria

Blue-green algae that sometimes produce toxins thrive as global warming heats up lakes, ponds and reservoirs. @bberwyn photo.

Staff Report

Scientists say it’s all but certain that global warming will increase potentially threatening outbreaks of freshwater algae that can produce toxins dangerous to people and animals.

A team lead by Tufts University researcher Steven C. Chapra has developed a modeling framework showing harmful algal blooms will increase the most in the northeastern region of the U.S. but that the biggest economic impact will be felt in the Southeast, where waters important for recreation will probably take a big hit.

The research, published in the journal Environmental Science & Technology, is part of larger, ongoing efforts among scientists to quantify and monetize the degree to which climate change will impact and damage various U.S. sectors. Continue reading “Eastern U.S. most vulnerable to future harmful algal blooms”

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Neonicotinoid pesticide stifles bumblebee egg-laying

Pollinators in peril

Can bumblebees survive the onslaught of pesticides? @bberwyn photo.

Staff Report

Exposure to systemic neonicotinoid pesticides causes queen bumblebees to lay 26 percent fewer eggs. That rate of decline could result in the extinction of some wild bumblebee populations, according to researchers at the University of Guelph.

Specifically, researcher Nigel Raine studied the impact of thiamoxin, one of the commonly used neonicotinoids, finding that exposure reduces the chances of a bumblebee queen starting a new colony by more than a quarter. Continue reading “Neonicotinoid pesticide stifles bumblebee egg-laying”

Sunday set: Bugs on blooms

In the woods …

It’s mid-summer, so all the bugs and plant are engaged in their eternal dance of life, with flowers blooming and pollinators doing their thing, all setting the stage for the next act of the play. But as you may or may not know, global warming has thrown many of these cycles out synch. Some of the best long-term research on this topic comes from the Rocky Mountain Biological Laboratory in Crested Butte, where scientists have shown how the shifting seasons are affecting butterflies and hummingbirds.

And when it comes to climate change, nature is kind of the opposite of Las Vegas. What happens there doesn’t stay there. All of nature is interconnected, so you can be sure that impacts to one part of the ecosystem will ripple through all the other parts eventually. The cycle of blooming plants and pollinating insects is so critical that there is actually a potential threat to food systems for humans. That doesn’t mean that we might not be able to address some of those challenges with technology or other innovations, but that’s bound to be expensive. It’s probably best to try and maintain natural ecosystem functions as best as we can by limiting global warming. And even if we do that right away, we’re still going to see some long-term impacts based on the warming that’s already locked into the climate system.

Global warming will devastate marginal farming areas

Southwest will be hit especially hard

Climate scientists have a pretty good understanding of how global warming will affect agriculture in different parts of the world. Is anybody listening? @bberwyn photo.

Staff Report

Most agriculture in the southwestern U.S. is already marginal, possible only because U.S. taxpayers support cheap water for questionable crops. And because of global warming, the outlook is grim as the region continues to warm and dry.

By 2050, Arizona cotton production will drop to less than 10 percent of the crop yield under optimal irrigation conditions, a new MIT study projects. Similarly, maize grown in Utah, now only yielding 40 percent of the optimal expected yield, will decrease to 10 percent with further climate-driven water deficits. Continue reading “Global warming will devastate marginal farming areas”

Climate extremes have big effect on wheat yields

New index helps project changes

Grain crops are very vulnerable to climate change impacts. @bberwyn photo.

Staff Report

Farmers have known it for generations that heatwaves, drought and extreme rain are a bad recipe for growing wheat, and now scientists have quantified those impacts. Heat stress, combined with drought or excessive rain is responsible for about 40 percent of the changes in wheat yields from one year to another.

That’s bad news in a world that’s expecting extreme weather to intensify in the coming decades, but at least the stress index developed scientists with the European Joint Research Centre will help communities plan ahead and ameliorate at least some climate change impacts. Continue reading “Climate extremes have big effect on wheat yields”

Is global warming killing bees?

Study finds 15 common bee species suffer as temps rise

A common bumblebee visits a garden in Vienna, Austria. @bberwyn photo.

Staff Report

The urban heat island effect isn’t just bad for people — it’s also harming bees, according to a new study from North Carolina State University.

“We looked at 15 of the most common bee species in southeastern cities and – through fieldwork and labwork – found that increasing temperatures in urban heat islands will have a negative effect on almost all of them,” said associate entomology professor Steve Frank. Continue reading “Is global warming killing bees?”

To save monarchs, plant milkweed — lots of it!

New USGS study quantifies conservation needs

A monarch butterfly in Florida. @bberwyn photo.
A group of monarch butterflies covers an oyamel fir tree at an overwintering site in the Piedra Herrada Monarch Butterfly Sanctuary in Mexico. (Steve Hilburger, USGS)

Staff Report

Saving monarch butterflies means planting a lot of their favorite food, say U.S. Geological Survey scientists, who outlined conservation measures in a new study.

After over-wintering in Mexico, monarchs rely on milkweed plants for food and breeding habitat. But milkweed has been wiped out across millions of acres. The new study measures the need in terms of stems of milkweed.

In the northern U.S. at least 860 million stems were lost during the last decade. After studying the density of Eastern migratory monarch butterflies overwintering in Mexico from 1979-2002 and the amount of milkweed plants available to them in North America. The study found that 3.62 billion milkweed stems are needed to reestablish this monarch population, but only 1.34 billion stems remain in the U.S.

“Monarchs in eastern North America are a beloved insect, but they’re in jeopardy, partly due to the loss of milkweeds in cropland,” said Wayne Thogmartin, a USGS scientist and the lead author of the report. “Our study is important because it helps specify the conservation needs of this charismatic species.” Continue reading “To save monarchs, plant milkweed — lots of it!”