Assessing Climate Change Below the Surface

groundwater recharge

Sure, we've heard of the effects of global warming on the oceans, atmosphere and the planet's surface but what about on soil and groundwater systems? While we may still be a ways from understanding just what the ramifications of intensified climate change will be on Earth's vast sub-surface, a team of scientists from the USDA and Australia's CSIRO have come up with an effective method to make projections about the impacts on groundwater — simulating interactions between soils and plants.

Using daily weather pattern data and predicted climate data — taking into account a doubling of current carbon dioxide levels — they created a soil-water-vegetation model that represented a number of variables, including soil absorbed water, water flow and deep drainage below the roots of plants that becomes groundwater recharge. Their results indicated that changes in global average temperatures and rainfall would affect the growth rates and leaf size of plants, with likely effects on groundwater recharge.

The study's authors conclude that in a world with double the current levels of carbon dioxide (a likely outcome, they claim), groundwater recharge will rise dramatically in some areas and decrease in others — a direct result of soil-water-plant systems, which control it, amplifying the effects of rainfall variations. Because many countries have groundwater reservoirs that constitute a significant portion of their total water supply, the authors continue, it is vital that policymakers and scientists gain a better understanding of the complex interactions between the climate, soil and groundwater. Doing so will allow us to predict future changes in the soil-water-plant systems more accurately and will also enable us to institute better water management practices when the time comes.

More importantly, they urge researchers not to forget that, with climate change — as with most matters in science and life — there are always two sides (or surfaces, in this case) to the equation.

Via ::EurekAlert: Climate change goes underground (press release)

Image courtesy of Timothy Green