Scientists have mapped the distribution of Earth’s wind-blown sand dunes at a global scale, providing a new way to study how sediment, wind and climate shape some of the planet’s driest landscapes. A sand dune is a hill or ridge of loose sand that has been formed and shaped by the wind. Dunes are commonly found in deserts and along beaches, wherever there is plenty of loose sand and enough wind to move it. Sand dunes are mainly classified into barchan (crescent-shaped), linear, star, parabolic, and transverse dunes, based on their shape and wind patterns.

The study, published in Nature Communications, finds that dune formation cannot be explained by aridity or wind speed alone. In dry regions, dunes are strongly associated with the movement of sediment towards areas where it accumulates. In wetter regions, stronger winds are needed to move enough sand to overcome the effects of vegetation and other surface conditions.

Andrew Gunn, a researcher at Monash University’s School of Earth, Atmosphere and Environment, built the map using globally available satellite imagery and topographic data. The resulting dataset identifies dunes across Earth’s continents and distinguishes their different forms.

The map covers dunes detected across about 7.8% of Earth’s surface. Their distribution is concentrated largely in the lower mid-latitudes, although the study found that the presence of dunes depends on a combination of sediment supply and the way wind transports that material.

Wind is Only Part of the Story

A desert may have strong winds and still lack dunes.

That is because wind needs loose sediment to move. The study found that in arid landscapes, the location of a dune field is closely tied to the availability and movement of sediment. Where material is supplied from several directions and transported towards the same area, sand can accumulate and produce dunes.

The picture changes in places with more rainfall. Vegetation and surface moisture can hold sediment in place, meaning winds need to be stronger before enough sand starts moving to build dunes.

The distinction matters when scientists use dunes as evidence of past environments. A dune’s shape and orientation can preserve information about the winds that formed it, but those features can also reflect the source and movement of the sand itself.

The researchers demonstrated this using barchan dunes, the crescent-shaped formations commonly found in areas where winds blow predominantly in one direction. Their orientation can provide information about wind direction, while their arrangement can also reveal something about sediment transport.

A Reference Point for Past Climates

Dunes can outlast the conditions that created them. Their position and form can therefore provide clues about earlier wind regimes, sediment movement and climate, particularly in places where direct observations do not exist. The new dataset gives researchers a consistent global reference rather than requiring them to compare separate regional maps made using different methods. That could be useful for studies of how dry landscapes have changed over time and how wind-driven erosion may respond to shifts in climate.

The map also has a planetary application. Mars has extensive dune fields, but scientists cannot measure its surface winds with anything close to the coverage available on Earth. Dune forms are therefore among the clues used to reconstruct Martian surface conditions.

The Earth dataset does not provide a direct translation from one planet to the other. Instead, it gives researchers a better understanding of how particular dune shapes relate to wind and sediment on Earth, which can inform interpretations of similar landforms on Mars.

The study’s value gives scientists a common dataset for asking why dunes occur where they do — and what their patterns can tell us about the landscapes that produced them.

A prolonged European drought combined with extreme heat is pushing major rivers to record lows, disrupting shipping and energy production while worsening crop losses and wildfire risks. As dry conditions spread north, Europe’s water, agriculture, ecosystems and public health systems are coming under increasing pressure.

A long period of low rainfall combined with extreme heatwaves has placed half of the European Union and the United Kingdom under drought conditions. A report published on August 12 by the European Commission Joint Research Centre and the European Drought Observatory reveals that nine percent of the region reached a critical alert level by late July.

Satellite data from Copernicus, the Earth monitoring program of the European Union, shows that severely dry soil is now damaging crops and plants across the continent. In its latest assessment, the observatory warned that “the drought has built up since early spring due to lower rainfall and higher than average temperatures, turning into fuel for devastating wildfires.”

European Drought Reaches Across the Continent

The lack of rain has driven four of Europe’s largest rivers—the Rhine, Danube, Loire, and Po—to dangerously low levels. Near Cologne, Germany, the Rhine fell to a fresh record low of 49 centimetres by mid-August, according to the Rhine Waterways and Shipping Authority — nearly 20 centimetres below the previous record of 68 centimetres set earlier in the summer, which had itself broken the prior all-time low recorded in 2018. Because large cargo boats need deeper water to float safely, operators have been forced to carry much lighter loads to avoid getting stuck on the riverbed, and in places river traffic has largely halted. Carrying smaller loads requires more trips, creating major shipping delays for important industrial materials across central Europe.

At the same time, low water levels and rising temperatures are creating a serious energy crisis across the continent. In France, power companies had to cut back nuclear energy production because river water became too warm to safely cool reactors without harming aquatic life. Hydroelectric power generation has also plunged across the Alps, northern Italy, and central-eastern Europe. Copernicus analysts noted that low river flows on the Danube are creating “serious operational challenges” for power plant cooling. In Italy’s Po Valley, the dried-out river basin has triggered a separate disaster: saltwater from the Adriatic Sea has flowed inland into depleted channels, ruining farmland soil and cutting off freshwater supplies for local crops.

Wildfires Burn Over 550,000 Hectares Across Europe

Dry plants and extreme heat have triggered widespread wildfires across the continent. According to August 11 data from the European Forest Fire Information System, 552,437 hectares of land have burned within the European Union since the start of the year, spread across 1,614 individual fires of 30 hectares or larger. Although this total remains below the 667,342 hectares burned by the same date in 2025 — a season that went on to become the worst on record for EU wildfires, with 1,034,552 hectares burned in total — it is significantly higher than the 20-year historical average.

Recent satellite data shows a clear shift: large wildfires are no longer staying just in southern hotspots like Spain and Greece. As dry weather pushes northward, fire risks are expanding into cooler regions, including northwestern France, southern Great Britain, the Alps, and the Balkans. Experts at the Joint Research Centre emphasized that “wildfire risk is no longer confined to southern Europe but is increasingly affecting wider parts of the continent under prolonged hot and dry conditions.”

Declining Harvests and Rising Health Risks

Continued heat and dry soil are dealing a heavy blow to European farmers. According to assessments by the European Joint Research Centre, crop yields across central and eastern Europe have dropped significantly. Production estimates for key spring and summer crops, such as grain maize and sunflowers, have fallen by six to seven percent. Winter crops have also suffered, with yield forecasts declining between one and four percent compared to earlier projections.

High temperatures are having a severe impact on human health as well. Monitoring data from public health agencies and the World Health Organization reveals a sharp surge in heat-related emergency admissions and deaths during extreme temperature episodes. Data compiled from national health agencies — including Germany’s Robert Koch Institute, which alone recorded an estimated 11,900 heat-linked deaths — put the region’s heat-related death toll above 25,000 as of early August, highlighting the severe human cost of this summer’s weather.

Seasonal Outlook and Emergency Response

Weather predictions indicate that dry conditions will continue through early autumn. According to the Copernicus Climate Change Service, drier and warmer weather is expected to persist across central-western Europe and southern Scandinavia through September. Climate experts also warn that a developing El Nino pattern could keep global temperatures higher than normal well into spring 2027. “Water resources, crops, energy systems, river transport, and ecosystems are all under growing pressure,” the report warned, with heatwave risks remaining high through August.

To coordinate emergency aid, the European Union activated its Civil Protection Mechanism. A dedicated fleet of 22 firefighting aircraft, 5 helicopters, and ground teams have been placed on standby across 12 countries. Meanwhile, the Copernicus satellite service has responded to more than 30 emergency requests since June, providing real-time mapping data to help local authorities track active fires and assess land damage on the ground.

India’s Asiatic lion population has increased from 523 in 2015 to 891 in 2025, a 70.4% rise over a decade. Union Environment Minister Bhupender Yadav highlighted the increase on World Lion Day, August 10, crediting forest officials, conservationists and local communities for the recovery. The increase is an important conservation milestone. But for a species whose wild population remains concentrated in a relatively small geographical range, rising numbers are only part of the story.

The Asiatic lion (Panthera leo persica) is one of India’s most significant wildlife conservation successes. Once found across parts of Asia, the subspecies was driven to near extinction by hunting and habitat loss. Its remaining wild population is now concentrated primarily in Gujarat’s Gir landscape and surrounding areas.

A Decade of Population Growth

India’s lion population increased from 523 in 2015 to 674 in 2020 and reached 891 in 2025. The latest increase represents a 70.4% growth over ten years.

The recovery reflects the impact of long-term protection, habitat management, prey availability, scientific monitoring and the involvement of communities living around lion habitats. But population size alone does not establish whether a species is fully secure.

For the Asiatic lion, where the animals live is almost as important as how many there are.

The Risk of a Concentrated Population

Unlike many large carnivore populations distributed across multiple countries and ecosystems, India’s Asiatic lions remain concentrated largely in Gujarat.

This creates a potential vulnerability. A major disease outbreak, extreme weather event, environmental contamination or other ecological disturbance affecting the Gir landscape could threaten a significant proportion of the population.

The risk became particularly evident during the 2018 canine distemper virus outbreak, when several Asiatic lions died. The episode demonstrated how infectious disease can become a serious conservation concern when a species is concentrated within a relatively limited landscape. Disease surveillance, veterinary care and monitoring have therefore become increasingly important alongside conventional habitat protection.

Why a Second Population Matters

The concentration of lions has also driven a long-running debate over establishing another free-ranging population. Kuno National Park in Madhya Pradesh has been proposed as a potential second home for Asiatic lions. The objective is not simply to increase the number of lions but to reduce the species’ dependence on a single geographical stronghold.

A geographically separate population could provide an additional safeguard if disease or another major disturbance affected the Gir landscape. However, the proposal has remained contentious, with questions around habitat suitability, prey availability, management and the transfer of lions from Gujarat. The debate reflects a wider conservation challenge: a species can have a growing population while remaining vulnerable because most of its individuals occupy the same landscape.

More Lions Also Mean a Greater Coexistence Challenge

Population recovery brings another issue into focus: human–wildlife coexistence. As lion numbers increase and animals disperse, they can move through agricultural and other human-dominated landscapes around the protected forests. This creates opportunities for wider habitat use but can also increase interactions with people and livestock.

For local communities, these encounters can mean livestock losses and safety concerns. Lions themselves face risks from roads, open wells, disease and other human-associated hazards.

This makes communities living around lion habitat an important part of the conservation equation. The long-term survival of the species will depend not only on protected forests but also on whether people and lions can continue to share the wider landscape.

For Sustainable Conservation

The increase from 523 lions in 2015 to 891 in 2025 shows that sustained conservation efforts can reverse a historic decline. But the next phase of conservation needs to ask more than whether the population is growing.

It must examine whether available habitat and prey can support further expansion, whether lions are becoming more geographically distributed, whether disease surveillance can detect outbreaks early and whether human–lion conflicts are increasing as the population grows.

The Asiatic lion’s recovery is therefore both an achievement and a reminder of the work ahead. For a species with a highly concentrated wild population, conservation success cannot be measured by numbers alone. Its real test will be whether the population becomes resilient enough to withstand disease, environmental change and the pressures of sharing its habitat with people.