Over watering lawns lost Los Angeles 70 billion gallons of water

The over watering of trees and lawns caused Los Angeles to lose 100 gallons of water per person per day to the atmosphere through evaporation in the summer of 2010, a new study found. Moreover, over-irrigation resulted in the loss of 70 billion gallons of water per year.

Lawns accounted for 70 percent of the water loss, while trees accounted for 30 percent, according to the study funded by the National Science Foundation and published in the journal Water Resources Research.

The study, based on measurements before Los Angeles mandated watering restrictions in 2014, show a “pattern of systemic overwatering of the city’s lawns, and a surprising water efficiency of its tree cover.” The researchers found a correlation between water loss and household income.

“California’s recent drought highlights the need for urban water conservation,” says Tom Torgersen, program director in the Division of Earth Sciences in NSF’s Geosciences Directorate.

Researchers measured evapotranspiration (ET), the evaporation of water from the soil and the transpiration, or release of water vapor, from plants

In Los Angeles, the greatest ET was due to turf grass and seed-producing trees.

“Both provide an alleviation of the urban heat island effect and reduce the need for air conditioning,” Torgersen says. “However, the benefit is not evenly shared. The higher the median income, the greater the local ET, with cooler temperatures in wealthier areas and higher temperatures in poorer sections of the city.”

ET rates in the wealthiest neighborhoods, they found, were roughly twice those of poorer neighborhoods.

Trees use far less water than grassy lawns, the study said. Under dry conditions, trees will rein in transpiration so they can retain water.

“It’s surprising that we can maintain the tree canopy of L.A. with relatively little water,” said Diane Pataki of the University of Utah, one of the researchers in the study. “There’s this assumption that we need abundant irrigation to support trees. But we can drastically reduce water use and still have trees.”

Los Angeles’ watering restrictions were lifted this spring after a very wet winter. At present, it’s too early to tell whether Los Angeles residents’ watering patterns and landscaping choices will return to pre-drought excesses, Pataki said.

“Whether the drought changed people’s landscape preferences in a lasting way, that’s something we still need to find out,” she said.

By: David Beasley, Earth.com Staff Writer

Source: National Science Foundation

Why climate change will make sleep more difficult

Warmer nights as a result of climate change will cause millions of people to lose sleep, with the poor and elderly most affected, according to a new study.

If climate change is not addressed, temperatures in 2050 could cost people in the United States millions of additional nights of insufficient sleep per year, the University of California San Diego study said. By 2099, the figure could rise by several hundred million more nights of lost sleep annually.

“Sleep has been well-established by other researchers as a critical component of human health,” said Nick Obradovich, who conducted much of the research as a doctoral student in political science at the University of California San Diego. “Too little sleep can make a person more susceptible to disease and chronic illness, and it can harm psychological well-being and cognitive functioning.”

The study analyzed federal health survey data from 765,000 U.S. residents between 2002 and 2011. It then linked data on self-reported nights of insufficient sleep to daily temperature data from the National Centers for Environmental Information.

The analysis showed that increases in nighttime temperature by 1 degree Celsius translate to three nights of insufficient sleep per 100 individuals per month.

Those earning below $50,000 a year and those over the age of 65 are most severely affected, the study found.

The study also paints a bleak picture for the future based on climate projections for 2050 and 2099 by NASA Earth Exchange.

Warmer temperatures could cause six additional nights of insufficient sleep per 100 individuals by 2050, and approximately 14 extra nights per 100 by 2099.

“The U.S. is relatively temperate and, in global terms, quite prosperous,” Obradovich said. “We don’t have sleep data from around the world, but assuming the pattern is similar, one can imagine that in places that are warmer or poorer or both, what we’d find could be even worse.”

The study, published by Science Advances, is the largest real-world study to date to find a relationship between reports of insufficient sleep and unusually warm nighttime temperatures. It is also the first to apply the discovered relationship to projected climate change.

By: David Beasley, Earth.com Staff Writer

Source: University of California San Diego

Global risk of natural disasters has doubled since 1975

Millions of people are impacted by natural disasters every year. These events often have the power to devastate entire regions, and can be very difficult to predict. A new study reveals that human exposure to natural disasters has doubled over the last 40 years, due mainly to population growth and urban development.

The team behind the study set out to get a better look at how much of the global population resides in regions that are susceptible to extreme weather events.

The researchers analyzed satellite observation data from the last 40 years, focusing their assessment on earthquakes, volcanoes, tsunamis, floods, and tropical cyclones. The evaluation revealed that an alarming number of people are vulnerable to natural disasters.

The team determined that earthquakes are the biggest threat to the largest amount of people. Between 1975 and 2015, the amount of people living in areas prone to seismic activity nearly doubled. This number grew from 1.4 billion to 2.7 billion, which is the equivalent of one out of every three people.

Flooding is the most frequent of the weather events examined for this study. In 2015, 1 billion people in 155 countries were found to be exposed to flood risk. The team established that 76.9 percent of those at risk are located in Asia. 8 million occupants of Germany are also more likely to experience flooding, along with 5.7 million residents of France.

Although regions of Asia are the most vulnerable to tsunami events, Japan has the most populated areas that are exposed to the likelihood of tsunamis. China and the United States also have heavily populated regions that are at high risk of tsunami activity.

Volcanic activity threatens around 400 people globally. The researchers noted that these people live in close proximity to the most dangerous volcanoes in the world.

Previous research that was conducted to determine the number of people impacted by natural disasters focused primarily on climate change. The authors of this study took a new approach by examining the connection between population growth, urban development, and extreme weather exposure.

As the world’s population and metropolitan areas continue to grow, the impact of natural disasters will continue to grow as well. The findings of this study are published in the Atlas of the Human Planet 2017.

By Chrissy Sexton, Earth.com Staff Writer

Source: Atlas of the Human Planet 2017

Scientists discover new tectonic plates in Earth’s mantle

A newly discovered layer of tectonic plates within the Earth’s mantle could explain a mysterious series of earthquakes in the Pacific, the Guardian reported.

On Tuesday, Jonny Wu of the University of Houston presented preliminary evidence of possible tectonics plate within the mantle to a joint conference of the Japan Geoscience Union and the American Geophysical Union in Tokyo.

The plate movements may explain a mysterious series of very deep, large earthquakes known as the Vityaz earthquakes, which originated in the mantle between Fiji and Australia. Just as in conventional tectonic plates at Earth’s surface, the bends and breaks in these subducted plates can generate earthquakes.

“Basically, 90% of Earth’s deep seismicity occurs at the Tonga area where we’ve found our long, flat slab,”  Wu told the Guardian.

The discovery has been made possible by recent advances in seismology allowing scientists to generate pictures of Earth’s interior using vibrations from natural earthquakes.

Wu compares the new pictures to images from the Hubble space telescope.

“Think of Hubble. We look out, and the further we look out the more things we discover, not just about the universe – we’re actually looking back in time,” he told the newspaper. “And this new seismology is like turning the Hubble to look into the Earth, because as we look deeper and get clearer images, we can see what the Earth might have looked like further and further back in time.”

The seismological pictures can be used to locate tectonic plates lurking within the mantle and then reconstruct the configuration on Earth’s surface millions of years ago.

“We’re discovering lost oceans that we didn’t even know existed,” said Wu, who with colleagues recently discovered an 8,000 km wide East Asian Sea which existed between the Pacific and Indian oceans 52 million years ago, and is now buried 500-1000 km deep in the mantle under east Asia.

By: David Beasley, Earth.com Staff Writer

Source: Guardian

Study: Diesel fuel pollution linked to heart damage

Diesel pollution can cause heart damage, according to a new study.

“There is strong evidence that particulate matter emitted mainly from diesel road vehicles is associated with increased risk of heart attack, heart failure, and death,” said lead author Nay Aung, a cardiologist and research fellow at Queen Mary University of London.

Heart damage is driven by an inflammatory response from inhaling particulate matter, Aung said. It starts with a localized inflammation of the lungs “followed by a more systemic inflammation affecting the whole body.”

The new study conducted cardiac magnetic resonance imaging on 255 participants to measure their heart‘s left ventricular volume and left ventricular ejection fraction. The particulate exposure was calculated based on the participant’s home address.

“We found that as [particulate] exposure rises, the larger the heart gets and the worse it performs,” Aung said. “Both of these measures are associated with increased morbidity and mortality from heart disease.”

More educated participants were less likely to have heart damage, the study found.

“This could be due to a number of factors including better housing and workplace conditions, which reduce pollution exposure,” Aung said. It could also be because people with more education have healthier lifestyles, and better access to healthcare, he added.

Aung advised people to avoid places with heavy traffic.

“If you want to cycle into work and there is heavy traffic around that time then try to find a quieter route,” Aung said. “Walk on the part of the pavement furthest from cars to reduce the amount of pollution you breathe in.”

By: David Beasley, Earth.com Staff Writer

Source: European Society of Cardiology

How increases in tree leaf abundance are affecting climate change

When we think of trees, we tend to mainly think about the benefits they provide to our existence on earth. They take in carbon dioxide and release oxygen, provide habitats for wildlife, and aren’t too hard on the eyes either. But new research shows that recent increases in tree leaf abundance may be having adverse effects on local climates.

A significant amount of our planet is greening in response to increasing carbon dioxide in the atmosphere – as well as nitrogen deposition, global warming, and changes in land use. Furthermore, a recent global assessment found that changes in leaf abundance could be causing northern areas to warm and arid regions to cool. Scientists believe this is related to how global vegetation has impacted local climates.

The increase in leaf coverage – which scientists call leaf area index (LAI) – may have major implications for climate change feedback loops. However, many researchers have had a hard time quantifying what these implications may be on a global scale.

In a new study, Giovanni Forzieri and colleagues used satellite data of global LAI coverage from the last three decades to analyze leaf coverage. They found that increased LAI in northern temperate zones where coniferous trees dominate resulted in a reduction in the reflection of sunlight from the ground. This is believed to have caused a warming effect. On the other hand, increased LAI in arid regions was related to more plants and trees absorbing water (known as transpiration), and thus caused a cooling effect.

The researchers also found that the relationship between LAI and surface biophysics are amplified up to five times during extreme warm-dry and cold-wet years.

Ultimately, the research team estimates that increased greening has actually buffered warming by about 14% across roughly 60% of the global vegetated area. However, in the remaining 40% – most of which are northern temperate regions – LAI increases have increased air temperatures, resulting in an additional warming of about 10%.

With global warming being such a significant topic these days – with potentially catastrophic consequences – it’s important that research such as this continues so that scientists may have a better understanding of how to curtail its effects.

By Connor Ertz, Earth.com Staff Writer

Source: American Association for the Advancement of Science