Climate change will cause more extreme wet and dry seasons, researchers find

July 13, 2020

The world can expect more rainfall as the climate changes, but it can also expect more water to evaporate, complicating efforts to manage reservoirs and irrigate crops in a growing world, according to a Clemson University researcher whose latest work has been published in the journal Nature Communications.

Ashok Mishra, who is the corresponding author on the new article, said that previous studies have focused mostly on how climate change will affect precipitation. But the key contribution of the new study is that it also examined the magnitude and variability of precipitation and evaporation and how much water will be available during the wettest and driest months of the year.

Researchers found that dry seasons will become drier, and wet seasons will become wetter, said Mishra, who is the Dean's Associate Professor in the Glenn Department of Civil Engineering.

Most of the Eastern United States, including all of South Carolina, has high precipitation that it is well distributed throughout the year, researchers found. The region and others like it can expect greater precipitation and evaporation in both wet and dry seasons, according to the study. The amount of water available will vary more widely than it does now, researchers found.

The greatest concern for such regions will be more flooding, Mishra said in an interview.

The regions that will be hardest hit by climate change are the ones that already get slammed with rain during wet seasons and struggle with drought during dry seasons, researchers found. They include much of India and its neighbors to the east, including Bangladesh and Myanmar, along with an inland swath of Brazil, two sections running east-west across Africa, and northern Australia, according to the study.

"The regions which already have more drought and flooding relative to other regions will further see an increase in these events," Mishra said.

As part of the study, researchers divided the world into nine land regions, or regimes. They looked at annual precipitation and how it fluctuates through the seasons for each region from 1971-2000.

Researchers then used that data to predict future water availability during each region's three wettest months and three driest months. They evaluated three scenarios based on multiple global climate models.

The best case scenario for relatively stable water availability during wet and dry seasons is that the global temperature will stabilize at 2 degrees Celsius over pre-industrial levels, according to the study.

But researchers also looked at what would happen if the temperature were to rise to 3.5 degrees Celsius or 5 degrees Celsius over pre-industrial levels by the end of the century.

The higher the temperature, the more variation in water availability, researchers found.

Mishra said that his message to the world is that water is a very important resource.

"The availability of this resource is an issue everybody is facing," he said. "We need to take precautions to optimally use how much water we have. As the climate changes and population increases, we should be preparing for the future by improving the technology to efficiently use water for crops."

Jesus M. de la Garza, chair of the Glenn Department of Civil Engineering, congratulated Mishra on publication of the research.

"Dr. Mishra and his team have taken a novel approach to examining climate change," de la Garza said. "Their work is a step toward developing sustainable solutions ensuring the world has an adequate water supply. With this new article, Dr. Mishra is helping raise Clemson University's global reputation for high-quality research."
-end-
The title of the article is, "Climate change will affect global water availability through compounding changes in seasonal precipitation and evaporation." You can read the full article it here.

Authors are Mishra; Goutam Konapala, who received a Ph.D. while studying under Mishra and was a postdoctoral researcher at Oak Ridge National Laboratory during the study; Yoshihide Wada of the International Institute for Applied Systems Analysis in Austria; and Michael E. Mann of Pennsylvania State University.

Clemson University

Related Climate Change Articles from Brightsurf:

Are climate scientists being too cautious when linking extreme weather to climate change?
Climate science has focused on avoiding false alarms when linking extreme events to climate change.

Mysterious climate change
New research findings underline the crucial role that sea ice throughout the Southern Ocean played for atmospheric CO2 in times of rapid climate change in the past.

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.

Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.

Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.

Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.

Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.

Read More: Climate Change News and Climate Change Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.