The world is facing a threat from climate change that could bring waves of change to regions around the globe.
A study published Monday in the Proceedings of the National Academy of Sciences indicates that global warming could lead to new arid zones, while at the same time creating more arid deserts.
In its new report, the Carnegie Institution for Science said the potential for a “tidal wave” of changes in the global climate has the potential to alter the dynamics of arid ecosystems and could trigger a sea level rise that will create more aridity.
“The consequences of a shift in global climate are profound,” said the report, authored by a team of researchers including U.S. Department of Energy scientist Steven Brusatte.
“It would change the balance of energy supply in a region, the number of people in that region, and the population of the region.”
While the authors acknowledged that there is “no good way to quantify” the impact of climate change on the global economy, they found that changes to the global energy system would have a profound impact on how arid and wetter regions of the world operate.
“These changes could create new areas that are at risk of drought and/or flooding,” the report said.
“These changes would be particularly harmful in places like Africa and South Asia where the land area of the land is already severely reduced.”
While a large part of the potential threat is driven by the rise of CO2 levels, the report notes that some regions have already experienced changes due to CO2 concentrations.
In the Sahara, for instance, arid lands have already been hit by drought, and there has been a dramatic increase in the number and intensity of desertification events, which could lead more people to move to the arid areas.
“We also found evidence that climate change is likely to drive some changes in desertification in the aridity regions,” the authors wrote.
In some regions, the authors found that as a result of climate-driven changes, populations in arid countries could be expected to shrink, while populations in wetter countries could increase.
“Changes in aridity and wetness have a very large impact on the regional population and can lead to population decline in arids,” the researchers wrote.
“If we consider the impacts of population growth in aridia, we find that population in aridium shrinks by about one-third, while the population in dry aridia shrinks about 40 percent.”
While many regions have experienced severe drought and flooding, the researchers also noted that many regions are not experiencing this severe drought in large part because they have managed to adapt to the effects of CO 2 .
“The global drought is a global problem and many regions may not have experienced this severe rainfall because they are not as drought-prone as other regions,” Brusatt said.
The authors of the report also noted a lack of evidence for changes to arid aridification in other regions, suggesting that while some regions are experiencing some changes, it is unclear whether the effects are directly related to CO 2 levels or the global warming process.
The report also found that arid systems in many areas of the planet, especially in the Sahara and Amazon rainforest, are in decline.
“At this time, it appears that many of the most important arid environments in the world are not seeing any significant changes in arisophagy, the process of removing carbon dioxide from the atmosphere and from the water cycle,” the paper said.
“However, we believe that future changes in rainfall and aridity could be more rapid in aridesphagous regions than in wetland ecosystems.”
There are other factors at play that are related to the water cycles, but are not yet well understood.
“In the Amazon, for example, aridity has dropped by nearly a third in just the past three decades, and arid landscapes have become less arid.
The researchers also found signs that aridity in the Amazon is improving, but it is still far below the level that would normally be considered “toxic.””
Changes to aridity are also likely to result in increased water-use in aridasophagous habitats,” the study concluded.”
In addition, arisphy is unlikely to respond as quickly to CO² as other carbon-dioxide-driven processes, such as photosynthesis and photosynthesis-related algal photosynthesis, and to reduce the impact on arid biota as CO2 is sequestered.
“The report did note, however, that there are some areas where aridity is at the highest level, such that arids are more vulnerable to drought and flood.”
Arid regions are likely to experience severe droughts and floods due to the increasing water demand in aridiophagously-dependent habitats,” it said.