Environmental and Political Factors Combine to Exacerbate Syrian Drought that Underpins Unrest

by Caroline Hays

Major climate events have social and political ramifications beyond their environmental impacts. In a recent study, Kelley et al. (2015) examine the extent of the drought in Syria that began in the winter of 2006/2007 and consider how it impacted the country socially and politically. The authors find that, although Syria has experienced several multiyear (three or more) droughts in the last 80 years, the most recent drought is the most extreme on record. Additionally, the authors note that three of the four most severe droughts recorded in Syria have taken place in the last 25 years. They connect the dots between anthropogenic climate effects, drought, agricultural collapse, and mass human migration, presenting a more comprehensive picture of a major climate event than is often shown. Continue reading

Combination of Heatwaves and Drought May Convert Carbon Sinks into Carbon Sources

by Caroline Hays

Droughts and heatwaves are becoming more common place and more severe. They impact the carbon and water cycles in terrestrial ecosystems, which affect the carbon sequestration capability of terrestrial ecosystems. As these extreme climate events become more common, their effects, both separately and together, on the atmospheric carbon balance will be important for accurately projecting global warming’s progression. Yuan et al. (2016) examined the effects of a heatwave and drought in Southern China in the summer of 2013. They found that this drought and heatwave were the most severe experienced in the last 113 years. These events significantly altered the carbon cycle in the region, decreasing carbon uptake enough to convert the region from its historical role as a carbon sink to a carbon source of nearly the same size during July and August of 2013. Continue reading

How Agricultural Intensification can Contribute to a more Favorable Agricultural Climate

by Caroline Hays

Food security is an ever growing concern in a world with an expanding population, an expanding demand for land-intensive meat production, and a finite amount of cropland. Crop productivity is a primary concern for food security and is largely affected by precipitation and temperature. Extreme temperatures caused by global warming and the subsequent climate change are a particular concern for crop productivity. In addition to global effects, local climate patterns are important for crop productivity. As it turns out, climate’s effects on crops are not a one way street: agricultural practices also exert their own influences on rainfall and temperature. Mueller et al. (2015) looked at this feedback loop in the US Midwest and found that cropland intensification has contributed to more desirable conditions for crops, leading to higher precipitation rates and more moderate extreme high temperatures. Continue reading

Influence of Extreme Weather Disasters on Global Cereal Production

by Coco Coyle

Increases in numbers and intensity of extreme weather disasters are linked to climate change and rising global temperatures. Agriculture is both a cause and a victim of climate change, and is susceptible to natural disasters and extreme weather disasters (EWDs). Lesk et al (2015) estimate global cereal production losses resulting from four major types of EWDs—extreme heat, droughts, extreme cold, and floods—in the period 1964–2007, analyze the underlying processes resulting in those losses, and identify several areas with potential for further study. They found that extreme heat disasters and droughts on average reduced national cereal production by 9–10%, while there was no significant drop in production from extreme cold and floods. Continue reading

The Beans that Will Survive Climate Change

by Abby Schantz 

Concerns about climate change are high on peoples’ minds around the globe, but not many consider the changes it is already beginning to cause in food production. Dan Charles of NPR discusses bean production in his article, “Meet the Cool Beans Designed To Beat Climate Change.” It is estimated that approximately 400 million people globally rely on beans for nourishment. This is problematic because most beans, including the common ones–pinto, black and kidney–cannot survive in temperatures that remain above 66 degrees throughout the night. A Colombian scientist, Alvaro Mejia-Jimenez was intrigued by a bean indigenous to communities in the American Southwest, the tepary bean. Continue reading

Global Warming May be Fatal to Forests

by Chloe Rodman

Jeff Tietz (2015) reports for Rolling Stone magazine on the work postdoctoral student Park Williams has been conducting in the past decade. After surveying thousands of trees, Williams created the forest-drought stress index, which determined that, due to climate change, the average forest stress caused by drought will, by 2050, surpass what it has been in the past 1000 years. Conifer forests in the Southwest United States will die, along with many other species across the globe. Continue reading

Drought Impacts on Children’s Respiratory Health in the Brazilian Amazon

by Allison Hu

Drought conditions in Amazonia are associated with increased fire incidence, enhancing aerosol emissions with degradation in air quality. On average, the Brazilian Amazon experiences extreme flood or drought once every ten years (Smith et al. 2014). However, in 2005 and 2010, only a five-year period, two mega droughts have occurred in the Amazon. Although the 2005 drought was the first in 100 years, the second drought occurred only five years later in 2010. Environmental impacts of drought include tree mortality from water deficits and social impacts include lack of food, lack of medical supplies, isolation of communities, and even health problems. Health issues arise because during droughts, wind erosion in deforested areas causes soil particles and microbes to be blow into the air, creating and exacerbating respiratory problems and triggering allergies. Furthermore, droughts have a positive correlation with fire incidences – in Amazonia, droughts can lead to over 30% increase in fire occurrence. This too leads to more hazardous health issues as smoke from fires tends to carry fine Particulate Matter particles (PM2.5), that when inhaled, may reach deep into the lungs, causing irritation of the throat, lungs, and eyes. The primary location for fires within the Amazon is centered around the southern and eastern periphery where 85% of fires occur, emitting as much as 300-600 mg/m3 of PM10 per 24 hours and up to 400 mg/ m3 of PM2.5 per 24 hours during the dry season (Smith et al.). Measurements carried out in southern Amazonia demonstrated that exposure to PM2.5 have positive associations with children’s respiratory health. This increase of 10 mg/m3 PM2.5 has shown simultaneous correlation with a 5.6% and 2.9% increase in outpatients in Rio Branco, Acre State, and Alta Floresta, Mato Grosso State, respectively. Continue reading

Heat Stress and Low Humidity with Climate Change will be Hard on Midwestern Corn Crops


by Christina Whalen and Emil Morhardt

Maize (corn) production continues to be a very important source of food, feed, and fuel all around the world, but climate change has raised the concern about being able to maintain the yield rates. A negative relationship between extremely high temperatures (above 30˚C) and yield has already been observed in various regions. Previous studies have not been able to demonstrate which mechanism causes the correlation between extreme temperatures and yield, thus it is possible that the relationship reflects the influence of another variable, such as precipitation rates. There are other possible explanations for the observed relationships. This study explores the mechanisms used in other studies that document the importance of extreme heat on rainfed maize using the process-based Agricultural Production Systems Simulator (APSIM). The study asks three main questions: can APSIM reproduce the empirical relationships—what farmers are seeing on the ground?; if so, what does APSIM imply are the key processes that give rise to these relationships?; how much are these relationships affected by changes in atmospheric CO2? Continue reading

Effect of Climate Change on Australian and Global Food Production

by Shelby Long

Recent droughts associated with climate change have had immense negative effects on food production in Australia. Australia is an important producer and exporter of livestock, dairy, and wheat. Much of the wheat produced is exported to Indonesia, Japan, South Korea, Yemen, Vietnam, and China. The Murray-Darling Basin is one of the main agricultural areas in the country, contributing 40% of Australia’s gross value of agricultural production. Water scarcity is accompanied by a high demand for water for both agricultural irrigation and non-agricultural uses (Quiggin and Chambers 2004). Therefore, it is necessary for crop producers to adopt new strategies to mitigate the impacts of drought. Some of these strategies include land use changes and introducing drought tolerant crop varieties. Qureshi et al. (2013) aim to use the Australian Bureau of Statistics (ABS) data and modeling to explore the possible future effects of Australian water Continue reading

Climate Change Increasing Water Scarcity

by Shelby  Long

The production of food and economic prosperity are highly dependent on a sufficient water supply. Both the demand and supply for water are affected by climate change-induced adjustments of precipitation patterns, temperature, other climate variables, and shifts in population. Much uncertainty remains among climate change models regarding how precipitation levels and patterns, as well as temperature, will change (Meehl et al. 2007). Also, precipitation changes affect other hydrological variables, such as surface or subsurface runoff and river discharge, and, therefore, effective hydrological and climate change modeling takes these variables into account. Schewe et al. (2013) use multiple global hydrological models (GHMs) and greenhouse-gas concentration scenarios to examine how climate change impacts global water resources. They determined that climate change is likely to intensify regional and global water scarcity. They project that a 2°C increase in global temperature will result in approximately 15% more of the global population experiencing a severe decrease in water resources. They also project this 2°C rise in temperature to increase the number of people living under absolute water scarcity by at least 40%, while some models predict a 100% increase. Along with climate change, they expect future population growth to Continue reading