Why Aardvarks Have Started Eating During the Day

New data sheds light on megadrought risk in Texas and extreme weather in South America, and some good news on wildfire smoke in this week's climate briefs

Ruth Schuster
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An aardvark in the Kalahari Desert, South Africa.
An aardvark in the Kalahari Desert, South Africa. Credit: Wits University
Ruth Schuster

Aardvarks eating in day as drought worsens

The aardvark of southern Africa is a shy beast that forages for ants and termites at night. So why are the nocturnal “ant bears” of Tswalu, a reserve by the Kalahari Desert, appearing in the daytime? Based on correlating satellite images of vegetation with observational data on aardvark excursions, it’s correlated with drought, reports a South African team in Frontiers in Physiology.  The vegetation dies and that in turn reduces ant and termite populations, so the hungry aardvarks forage by day too. “Aardvarks have coped with the Kalahari’s harsh environment in the past, but it is getting hotter and drier, and the current and future changes to our climate might be too much for the aardvarks to bear,” said Nora Weyer of the University of the Witwatersrand, Johannesburg.

An aardvark in the Kalahari Desert, South Africa.
An aardvark in the Kalahari Desert, South Africa. Credit: Wits University

Forecast: Texas to face driest conditions in last 1,000 years

Texas was quite wet when the last Ice Age ended but has since been much as it is now, marked by some wetter periods and some of megadrought lasting years to decades. Now, research based on the latest climate models indicates that in this century, the state will experience “drier conditions during the latter half of the 21st century than even the most arid centuries of the last 1,000 years that included megadroughts,” according to a report in the journal Earth’s Future. “Our study shows that the drier conditions expected in the latter half of the 21st century could be drier than any of those megadroughts, depending on how you measure dryness,” said Prof. John Nielsen-Gammon, director of the Texas Center for Climate Studies and the Texas state climatologist. The time to act, says the team, is now.

Study shows rising rate of South American extreme weather

Extreme weather has become more frequent in South America too in recent decades, according to a South American Drought Atlas published in PNAS going back 600 years. Scientists reconstructed 600 years of soil-moisture swings across southern and central South America based on tree ring analysis, and found that widespread, intense droughts and unusually wet periods have been on the rise since 1930, potentially endangering food security.

Co-author Edward Cook, head of the Tree Ring Lab at Columbia University’s Lamont-Doherty Earth Observatory, qualified: “We don’t want to jump off the cliff and say this is all climate change”: some could be due to natural variability that may mimic human-induced climate change. However, in North America, analysis indicates that warming is driving what may be the worst-ever known drought in the American West (see Texas above). Jason Smerdon of Lamont-Doherty added that “everything is consistent with the idea that you’ll be intensifying both wet and dry events with global warming.”

Warming may cause extreme waves in Arctic

The heights of “extreme waves” in the Arctic waters could double or even triple, warns a study in the Journal of Geophysical Research: Oceans, published by the American Geophysical Union. The waves could become some 2 meters (6 feet, 7 inches) higher than their present heights, posing danger to coastal communities, the scientists project. Higher waves could accelerate Arctic ice breakup, too. And, like storms, they’re predicted to become more frequent. Extreme wave events that had been clocked every 20 years on average might happen every two to five years on average, the collaborators project. 

Wildfire smoke may boost warming less than thought

In what counts as good news these days, new research indicates that wildfire smoke particles may have less impact on climate than was widely hypothesized. A study led by the Los Alamos National Laboratory on the properties of smoke from Arizona’s month-long Woodbury Fire in mid-2019, measured over hundreds of kilometers, showed that chemical reactions between the dark particles and atmosphere (clean air) reduced the plume’s heat-absorbing power and hence its climate-warming effect. At the fire’s core, the smoke did absorb light at a potency that validated previous observations, but as the smoke dissipated, the particles at its edges were not only fewer but had oxidized and absorbed less light, the researchers explained in the journal JGR Atmospheres.

The Nelson Fire burns near Oroville, California, June 17, 2020. Wildfire smoke particles may have less impact on climate than was widely believed.
The Nelson Fire burns near Oroville, California, June 17, 2020. Wildfire smoke particles may have less impact on climate than was widely believed.Credit: /AP

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