We are changing our environment with steadily increasing carbon dioxide emissions, but we might be able to help. The authors here use a computer program called Community Climate System Model 4 to predict the effects of spraying small particles into the atmosphere to reflect away some of the sun's rays. The software predicts that this could reduce the amount of energy the Earth's atmosphere absorbs and may limit but will not completely counteract our carbon dioxide production.
Farmers will need to increase crop yields to feed the world's growing population efficiently. The authors here investigate the effects of growing corn in the presence or absence of ragweed, an invasive weed found in many fields and gardens. Surprisingly, the authors found that corn grown in the presence of weeds grew taller and were more productive than corn that had weeds removed. This may help gardeners rethink the necessity of weeding, and may point a way to improve farm yields in the future.
Climate change is one of the most controversial challenges humans face. Here the authors investigate the dual role of clouds - to reflect incoming light away from the Earth and to reflect heat energy back toward the Earth's surface. They find that the amount of incident light energy and surface temperature decreases as the sky becomes cloudier. These results will inform longer-term studies that may compare against the amount of energy clouds reflect back toward the Earth.
The water we use must be treated and cleaned before we release it back into the environment. Here, the authors investigate two new techniques for purifying dissolved impurities from waste water. Their findings may give rise to more cheaper and more efficient water treatment and help keep the planet greener.
Rising atmospheric carbon dioxide levels are projected to lead to a 0.3- 0.4 unit decrease in ocean surface pH levels over the next century. In this study, the authors investigate the effect of pH change on the mass of calcified exoskeletons of common aquatic organisms found in South Florida coastal waters.
Plants in the wild compete with each other for nutrients and sunlight. Kudzu is a weed that is thought to secrete compounds that inhibit the growth of other plants. Here the authors find that certain parts of kudzu plants can block the germination of clover and dandelion seeds. These experiments may lead to a weed killer that is safe and naturally derived.
Climate change is an important and contentious issue that has far-reaching implications for our future. The authors here compare primary temperature and precipitation data from almost 200 years ago against the present day. They find that the average annual temperature in Brooklyn, NY has risen significantly over this time, as has the frequency of precipitation, though not the amount of precipitation. These data stress the need for more ecologically-conscious choices in our daily lives.
Polylactic acid (PLA) is a bio-based, compostable plastic that is comparable in cost to petroleum-based plastics. This study aims to evaluate the effects of UV treatment and mechanical chopping on the degradation of PLA. Based on their findings, the authors propose an alternative PLA degradation process that may be more time and energy efficient than current processes.
Every year, around 40% of undergraduate students in the United States discontinue their studies, resulting in a loss of valuable education for students and a loss of money for colleges. Even so, colleges across the nation struggle to discover the underlying causes of these high dropout rates. In this paper, the authors discuss the use of machine learning to find correlations between the built environment factors and the retention rates of colleges. They hypothesized that one way for colleges to improve their retention rates could be to improve the physical characteristics of their campus to be more pleasing. The authors used image classification techniques to look at images of colleges and correlate certain features like colors, cars, and people to higher or lower retention rates. With three possible options of high, medium, and low retention rates, the probability that their models reached the right conclusion if they simply chose randomly was 33%. After finding that this 33%, or 0.33 mark, always fell outside of the 99% confidence intervals built around their models’ accuracies, the authors concluded that their machine learning techniques can be used to find correlations between certain environmental factors and retention rates.