Though a border wall with Mexico is currently a matter of serious discussion in the United States, the aim of which is to prevent the physical movement of people (with few other apparent “benefits”), some walls can actually bring together and preserve communities, rather than divide them.

In only five years, the UN says, around 60 million Africans may be displaced as their land ceases to be arable, a potential humanitarian disaster the scale of which would be unprecedented. This would be devastating to a huge portion of the African continent not only ecologically and economically but socially as well.

That’s where Africa’s ingenious Great Green Wall comes in.

Experts at the United Nations say without action, desertification may claim two-thirds of Africa’s farmlands in under a decade. The Great Green Wall, however, was conceived as a wide-reaching strategy to halt Northern Africa’s rapidly advancing Sahara Desert.

The Great Green Wall, once complete, will stretch an incredible 4,400 miles from Senegal in West Africa to the East African nation of Djibouti. Instead of bricks and mortar, the wall will be made of trees and other vegetation, including plants that can be eaten or used to create medicine.

The idea that the young Earth had a thicker atmosphere turns out to be wrong. New research from the University of Washington uses bubbles trapped in 2.7 billion-year-old rocks to show that air at that time exerted at most half the pressure of today’s atmosphere.

 Air pollution legislation to control fossil fuel emissions and the associated acid rain has worked – perhaps leading to the need for sulfur fertilizers for crop production. A University of Illinois study drawing from over 20 years of data shows that sulfur levels in Midwest watersheds and rivers have steadily declined, so much so that farmers may need to consider applying sulfur in the not too distant future.

“We don’t think there are actual sulfur deficiencies yet, but clearly more sulfur is coming out of the soil and water than what is going in,” says U of I biogeochemist Mark David. “As the Clean Air Act and amendments have taken effect there has been a reduction in sulfur emissions from coal combustion, so that the amount of atmospheric sulfur deposited each year is only 25 percent of what it used to be. At some point, farmers are going to have to fertilize with sulfur.”

A recent study released by the National Aeronautics and Space Administration (NASA) concludes that the current drought that began in 1998 in the eastern Mediterranean Levant  – which includes Cyprus, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey – is the region’s worst dry spell since 1100 C.E.

NASA scientists reconstructed our regional drought history by studying records of tree rings, from dead and live specimens, across several Mediterranean countries to determine patterns of dry and wet years over a 900-year time span. Tree rings are good indicators of precipitation since dry years cause thin rings while thick rings show when water was plentiful. They concluded that the years between 1998 and 2012 were drier than any other period, and that the drought was likely caused by humans.

Ben Cook, lead author and climate scientist at NASA’s Goddard Institute for Space Studies and the Lamont Doherty Earth Observatory at Columbia University in New York City, said the range of regional weather events has varied widely over the last millennium, but the past twenty years stand out as extreme, falling outside the range of natural variability.

Canada is no stranger to wildfires, but this week’s ferocious blaze in Fort McMurray is extreme — even by Canadian standards. 80,000 people have fled from the heart of tar sands country in an unprecedented evacuation effort.

As people consign their homes and belongings to the flames and firefighters struggle to contain the blaze, there’s an inevitable question: Do we have climate change to thank for the intensity of this fire?

This issue is emerging all over the world as shifts in the climate drive environmental imbalances that promote the spread of fire. Droughts turn the landscape into tinder, and tree die-offs create ample fuel for fast-moving, incredibly hot fires that can whip through the landscape at terrifying speeds.

Coastal wading birds shape their lives around the tides, and new research in The Auk: Ornithological Advances shows that different species respond differently to shifting patterns of high and low water according to their size and daily schedules, even following prey cycles tied to the phases of the moon.

Many birds rely on the shallow water of the intertidal zone for foraging, but this habitat appears and disappears as the tide ebbs and flows, with patterns that go through monthly cycles of strong "spring" and weak "neap" tides. Leonardo Calle of Montana State University (formerly Florida Atlantic University) and his colleagues wanted to assess how wading birds respond to these changes, because different species face different constraints--longer-legged birds can forage in deeper water than those with shorter legs, and birds that are only active during the day have different needs than those that will forage day or night.

Most of us think of that sweet smell after a storm as the aftereffect of rain that has rinsed the air of pollutants and dust. But it turns out that rain also triggers the release of a mist of particles from wet soils into the air, a finding with consequences of its own for how scientists model our planet's climate and future.

The evidence comes in the form of tiny glassy spheres, less than one-hundredth the width of a human hair, discovered at the Great Plains of Oklahoma after a rainstorm and put under scrutiny by scientists at several U.S. Department of Energy facilities. The study appears May 2 in Nature Geoscience.

According to the authors, scientists have largely assumed that organic particles from the soil enter the air through erosion by wind or through agricultural work. The effects of rain splash haven't been part of the discussion.

But the team's field observations indicate that up to 60 percent of particles that are airborne after a rainstorm in certain areas, such as grasslands and tilled fields, come from the soil. These organic particles are carbon-based and come from decaying vegetation and organisms. The tiny bits of organic matter can hold tremendous sway over our climate, playing a role in the fate of sunlight as it hits Earth.

Authors of the study are from two DOE Office of Science user facilities — EMSL, the Environmental Molecular Sciences Laboratory at the Pacific Northwest National Laboratory, and the Advanced Light Source at Lawrence Berkeley National Laboratory — as well as the Berkeley Lab and the University of Massachusetts at Amherst.

Chemist Alexander Laskin led the team at PNNL and chemical scientist Mary Gilles led the group at the Berkeley Lab.

From a quarter to half of Earth’s vegetated lands has shown significant greening over the last 35 years largely due to rising levels of atmospheric carbon dioxide, according to a new study published in the journal Nature Climate Change on April 25.

While currently more than half of the world’s coral reefs are potentially threatened by humans, scientists just made an incredible discovery: a coral reef the size of Delaware flourishing near the mouth of the murky and Amazon River in Brazil.

Coral reefs don’t typically thrive in murky waters, which makes the discovery even more shocking.

Although northern long-eared bat populations have declined by 90 percent in their core range, the U.S. Fish and Wildlife Service today said it will not protect any of its critical habitat, saying it would not be “prudent” for the species. Under the Endangered Species Act, the government can opt not to designate critical habitat if there is factual evidence that a species would be placed at greater risk of extinction from poachers, collectors or vandals. But in the case of the northern long-eared bat, which is listed as “threatened” under the Endangered Species Act, there is almost no evidence that the species is at risk from these types of threats. Instead its dramatic decline has been driven mostly by disease and habitat loss.  

“This is a terrible turn of events for the northern long-eared bat,” said Tanya Sanerib, an attorney at the Center for Biological Diversity. “If you don’t protect the places endangered species live, it becomes that much harder to save them. This is yet another instance where the Fish and Wildlife Service has gone out of its way to appease special interests rather than protecting our most vulnerable animals.”