Rising sea levels are increasingly being attributed to land, rather than ice melt.
In a groundbreaking study published in Science Advances, researchers have highlighted the alarming expansion of dry regions worldwide, a trend primarily driven by climate change and human activities.
The study reveals that Earth's land is currently contributing more to rising sea levels than melting glaciers, as the expansion of dry regions reduces total water storage and freshwater availability. This, in turn, impairs water supply for ecosystems and human use, a concerning development for the 75% of the world's population (nearly six billion people) that could face water shortages as a result.
The continued overuse of groundwater, particularly in regions like California, is undermining regional and global water and food security. The study emphasizes the need for key decisions, both at national and international levels, to help preserve groundwater resources for future generations.
Climate change-induced rising temperatures and increased severity and frequency of droughts are key factors causing the expansion of dry regions. These factors, combined with human pressures such as overgrazing, mining, and land use changes, create a feedback loop where vegetation loss leads to soil degradation and further desert expansion.
According to the study, climate change drives about 80-90% of drought intensification by increasing evaporative demand due to higher temperatures, causing water to evaporate faster and soils to dry out more severely. Vegetation loss reduces soil stability, allowing wind and sand to degrade remaining plants and spread desert conditions further into previously less arid areas.
Melting glaciers and ice caps also contribute indirectly by altering freshwater availability, affecting regional water cycles and contributing to overall drying trends.
The study tracks water storage across Earth's land surface, including in groundwater aquifers. Using satellite observations taken between 2002 and 2024, researchers found that water lost from soil, lakes, and underground aquifers is accelerating sea level rise.
One such 'mega-dry' zone stretches from the southwest coast of the US down into Mexico, and one example of this is the merging of dry areas in these regions with those in Central America to form a giant dry region.
The overuse of groundwater is a pressing issue that requires urgent action to help preserve this precious resource for future generations. The study underscores the importance of protecting the world's groundwater supply in a warming world and on continents that are drying.
The expansion of dry regions harms food security, leads to ecosystem collapse, and increases economic and energy insecurity due to water shortages, indicating broad global impacts on human and ecological systems. Climate change is driving changes in water storage patterns, and in many places where groundwater is being depleted, it will not be replenished on human timescales.
In summary, rising temperatures from climate change combined with human land-use pressures cause dry region expansion. This worsens drought, shrinks freshwater supplies worldwide, and indirectly contributes to sea level rise by reducing terrestrial water storage. The consequences include ecosystem degradation, biodiversity loss, increased food insecurity, and heightened vulnerability of water resources globally.
Earth's research into climate change has revealed that rising temperatures and increased droughts, primarily driven by climate change and human activities, are causing the expansion of dry regions across the globe. This expansion has significant implications, as it contributes more to rising sea levels than melting glaciers due to reduced total water storage and freshwater availability. The study also emphasizes the need for science and environmental-science-based decisions to preserve groundwater resources, crucial for health-and-wellness and sustaining 75% of the world's population. The consequences of dry region expansion include harm to food security, ecosystem collapse, and increased economic and energy insecurity due to water shortages. Scientists tracking water storage patterns have found that the overuse of groundwater, a pressing issue, will not be replenished on human timescales in many places, making it vital to take urgent action to protect this precious resource for future generations.
