Your Deodorant is Causing Air Pollution

When you think of air pollution, you might think of smog or automobile emissions, but think again. Scientists at the Cooperative Institute for Research in Environmental Science at the University of Colorado, Boulder and NOAA have recently published in Science in February 2018 detailing their findings that petroleum-based chemicals used in items like perfumes, soaps, deodorants, and paints emit as much volatile organic compounds (VOC) as motor vehicles. VOCs interact with particles in the air that then develop into smog primarily in the form of ozone, which can trigger asthma as well as scar lung tissue. They can also develop into a type of pollution called PM2.5 that has been linked to heart attacks, strokes, and lung cancer.

Visible Air Pollution in New Delhi, India. Source: Flickr

After regulations were developed in the 1970s to limit VOC emissions from automobiles, commodities like pesticides and personal care products became increasing cause of air pollution. The stricter regulations on car emissions made it more obvious than ever to scientists that household and personal products were a bigger threat to air quality. The study was influenced from past measurements collected of VOCs in California, which had shown higher concentrations of petroleum-based compounds at higher levels than initially predicted from fossil fuel sources alone.

Researchers realized that even though drivers use far more fuel (by weight) than they do personal or household products, gasoline is “stored in an airtight tank, it’s burned for energy, and converted mostly to carbon dioxide,” said Jessica B. Gilman, who was involved in the study. Since carbon dioxide emissions are not smog-forming VOCs, it does not contribute to air pollution as much as a spray or squirt of a petroleum-based product, most of which ends up in the atmosphere.

For their calculations, the authors of the study created a computer model that simulated air quality in Los Angeles by using data from the chemical composition of tailpipe emissions consumer goods. Based off these calculations, they found that roughly half of the VOCs in the air could be attributed to consumer products.

These findings have huge implications for human health, especially because most consumer products are used indoors. The traditional approaches to mitigate air pollution are not enough because they commonly focus on transportation or industrial sources. The regulations need to be extended to consumer products as well to mitigate their effects on environmental and human health. If you want to do more to decrease your impact on air pollution, “natural” products aren’t necessarily the answer, as many chemicals used in these products are incredibly reactive and well still form VOCs. The best option is to use as little household product as you can when you need to.

McDonald, B. b., de Gouw, J. A., Gilman, J. B., Jathar, S. H., Akherati, A., Cappa, C. D., & … Trainer, M. (2018). Volatile chemical products emerging as largest petrochemical source of urban organic emissions. Science359(6377), 760-764.



Restoration of the Gulf Takes More Than Money

Sediment-laden water pours into the northern Gulf of Mexico from the Atchafalaya River in an image taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on April 7, 2009.
Source: Nasa

Researchers at University of Waterloo published a study in Science in late March of 2018 giving new insight into the fact that restoring the water quality in the Gulf of Mexico is harder than originally thought. The Gulf of Mexico contains a hypoxic or dead zone, an area found in bodies of water that have extremely low levels of oxygen due to excessive nutrient pollution from human activities. Recently, attempts have been made to reduce the size of the Gulf’s dead zone, but despite these investments of large amounts of money, researchers have concluded that the legacy of nitrogen is so intense that these goals are unrealistic.

This dead zone is due to large quantities of nitrogen being carried through rivers and streams across the North American corn belt to the Gulf. Massive algal blooms sparked by the concentration of nitrogen leads to oxygen depletion, making it more difficult for marine life to survive. Due to its continual expansion, this area is approximately the size of New Jersey, and will continue to grow unless drastic measures are taken. Major changes in agricultural and river management practices must be made in order to see any type of improvement of water quality.

Researchers compiled and analyzed more than two centuries of agricultural data, showing that nitrogen has been accumulating in soil and groundwater due to intensive agricultural production. The water quality of the Gulf of Mexico has been declining since the 1950’s. It’s hypoxic zone is mainly caused by use of fertilizer and intensive livestock production. Manure and fertilizer are both rich in nitrogen, and can easily enter watersheds through runoff.

After this analysis, researchers modeled the results and concluded that even under best-case scenarios where effective conservation measures are implemented instantly, it would take over 30 years to restore the Gulf of Mexico through depletion of excess nitrogen. They continue their analysis to phosphorus, which is a major instigator of algal blooms in inland waters

The need for intensive agricultural production is only increasing, nitrogen quantities will continue to rise do to this, creating a massive problem for marine life around the globe. Effective policy must be implemented to curb the growth of this massive dead zone in the Gulf of Mexico, which imposes a great risk on marine ecosystems all over the region.

K. J. Van Meter, P. Van Cappellen, N. B. Basu. Legacy nitrogen may prevent achievement of water quality goals in the Gulf of MexicoScience, 2018; eaar4462 DOI: 10.1126/science.aar4462

Winter is Coming and Staying

Snowfall in Boston
Snowfall in the Greater Boston area has been so severe this year that some public schools have extended classes until July. Source: Flickr

Extreme winters have become the new norm in northeastern states of the United States, and researchers have recently found the reason why. In March of 2018, scientists at Rutgers University published a study in Nature Communications on their findings that there is a correlation between the frequency of extreme winter weather in the North-Eastern region of the United States to changes in Arctic temperatures.

Recently warm temperatures in the Arctic cause the jet stream – a band of strong westerly air currents that encircle the globe several miles above the earth’s surface – to occasionally move farther south, causing cold air to reach all the way down to the eastern United States. The timing of this research is somewhat convenient, as it follows increasingly extreme winters, as well as record warm Arctic temperatures and low sea ice, record-breaking disruptions in the polar vortex (a large area of low pressure and cold air surrounding both of the Earth’s poles), and record-breaking disruptive snowfall in the United States and Europe.

Researchers found that severe winter weather is two to four times more likely to occur in eastern United States when the Arctic is abnormally warm than when it is colder than normal. The study also showed that colder winters in the northern latitudes of Europe and Asia are significantly related to the warming of Arctic. On the other hand, the study also showed a correlation between the likelihood of severe winter weather in the western United States when the Arctic is colder than normal.

Researchers found that when warming of the Arctic occurs on the Earth’s surface, there is only a weak connection to severe winter weather in the northeastern region of the United States. However, when warming is extended to the stratosphere, it disrupts the polar vortex and severe weather is more likely.

To make these conclusions, researchers used three metrics of Arctic variability to diagnose the relationship between severe winter weather in the Northeast and Arctic temperatures. These measurements are called the polar cap geopotential height anomaly index (PCH), polar cap air temperature anomaly index (PCT), and the Accumulated Winter Season Severity Index (AWSSI).

The PCT and PCH indices measure geopotential height (the vertical coordinate system referenced to Earth’s mean sea level) and temperature anomalies that occur between the 65th parallel north (a circle of latitude that is 65 degrees north of the Earth’s equator) and the north pole. The AWSSI identifies severe weather owning to snowfall and temperatures at individual locations across the United States. Researchers analyzed changes in AWSSI in relation to changes in PCT and PCH to explore the relationship between Arctic variability and severe winter weather.  They found that an increase in abnormalities occurring in polar cap temperatures and geopotential height are correlated with higher values of the AWSSI, meaning an increase in cold spells and heavy snowfalls.

Inevitably, there will be an increase in certain types of weather extremes due to the effects of anthropogenic global warming. Researchers at Rutgers University have presented a quantitative analysis of the link between Arctic variability and severe winter weather, suggesting that the pattern of colder and harsher winters in the Northeast are attributed to Arctic warming is no coincidence.

Judah Cohen, Karl Pfeiffer, Jennifer A. Francis. Warm Arctic episodes linked with increased frequency of extreme winter weather in the United StatesNature Communications, 2018; 9 (1) DOI: 10.1038/s41467-018-02992-9

Soil Cannot Mitigate Climate Change

Crop Field: Using crops to transfer carbon dioxide into the soil has been found to be an unrealistic option.

It was once a groundbreaking idea that that climate change mitigation was plausible by burying carbon in the ground. However, in late February of 2018 scientists at Rothamsted Research published their findings in the journal Global Change Biology that soil data stretching back to the mid 19th century demonstrates that carbon emissions cannot be stored in the ground. The researchers concluded this by analyzing of the rate of change in carbon levels in soil.

The original idea of using crops to collect carbon from the atmosphere and burying it in the soil was proposed in 2015 at an international conference. The aim of this proposal was to increase carbon sequestration (the removal of carbon dioxide from the atmosphere and holding it solid or liquid form) by “4 parts per 1000.” The researchers at Rothamsted insisted that this rate was unrealistic for such large areas all over the planet, stating that levels of soil carbon are not unrestricted; as the levels increase, they move towards equilibrium and eventually stop growing.

Data from 16 experiments on three different soil types were examined, giving 110 treatment comparisons. The researchers observed the “4 per 1000” rate of growth in soil carbon levels in some cases, but only when such extreme measures were taken that they would be impractical in a real-life setting.

Not only did these experiments prove the impracticality of the “4 per 1000” initiative, but also displayed that high rates of soil carbon increase can be achieved by removing land from agriculture. However, this extreme decrease in agriculture over vast expanses of land would be incredibly damaging to global food security. To mitigate this problem, researchers have suggested returning residue from crops to soil as an effective solution to increase carbon soil sequestration; this has been observed as an practical method used by some countries in smallholder agriculture settings.

The researchers also suggested that long-term crop rotation with occasional introduction of pasture could lead to significant soil carbon increases. While the environmental benefits are clear, this method is economically impractical for most farmers. In order for an effective change in agricultural methods to be plausible, there would have to be implementation of new policy or guidelines.

Overall, the “4 per 1000” initiative is unrealistic as a major contribution to climate change mitigation. The scientists at Rothamsted Research suggest that there has to be more logical reasoning for promoting practices that increase soil carbon levels is more important to ensure sustainable food security and wider ecosystem services.

Paul Poulton, Johnny Johnston, Andy Macdonald, Rodger White, David Powlson. Major limitations to achieving “4 per 1000” increases in soil organic carbon stock in temperate regions: Evidence from long-term experiments at Rothamsted Research, United KingdomGlobal Change Biology, 2018; DOI: 10.1111/gcb.14066

How Drastic Deforestation Is Causing the Earth’s Surface to Heat up

Source: Flickr

Forest ecosystems are a large carbon sink because of their ability to absorb carbon dioxide from the atmosphere. They play a huge role in the mitigation of climate change, but the impacts of deforestation has cause the Earth’s surface to heat up. Researchers at the European Commission Joint Research Centre published an article in February of 2018 in the journal Nature Connections detailing how recent changes to the vegetation that covers the earth is causing it to heat up. They examined the effects of cutting down vast expanses of evergreen forests for agricultural expansion on energy imbalances that contribute to the rise in local surface temperatures and global warming overall. These actions have alter radiative and non-radiative properties of the surface.

Using satellite data, the researchers analyzed changes in vegetation cover from 2000 to 2015 all over the world and linked them to changes in the surface energy balance. The statistical relationship between maps of vegetation cover and variables detailing surface properties acquired by satellite imaging was then analyzed.

The researchers also examined changes between different types of vegetation, including evergreen broadleaf forests, deciduous broadleaf forest, evergreen needle leaf forests, savannas, shrublands, grasslands, croplands, and wetlands. While deforestation results in overall higher levels of radiation leaving Earth’s surface, the balance between the shortwave light the sun emits and the longwave energy the reflects changes depending on forest type. From their observations, researchers concluded that removing tropical evergreen forest for agricultural expansion is the most responsible for an increase in surface temperature locally.

Altering the vegetation cover changes its surface properties drastically, affecting an increase in the level of heat dissipated by water evaporation and the levels of radiation reflected back into space. Overall, the researchers determined that land use change has made the planet warmer. Clearly, these forest ecosystems play an important role in combating the effects of air pollution, soil erosion, and overall climate change.

Gregory Duveiller, Josh Hooker, Alessandro Cescatti. The mark of vegetation change on Earth’s surface energy balanceNature Communications, 2018; 9 (1) DOI: 10.1038/s41467-017-02810-8

Climate Change Increases Vulnerability for Millions who Rely on Grazing Lands

Livestock Grazing on Public Land
Credit: flickr

In February 2018, researchers at the University of Minnesota published a study in Nature Climate Change showing how precipitation variability has increased significantly on 49% of the world’s grazing lands. This variation in precipitation can have detrimental effects not only on the environment as a whole but also on the livelihoods of those who rely on livestock that graze on natural vegetation for food security.

Using climate data from 1901 to 2014, the researchers studied precipitation variability trends and concluded that grazing lands experienced an overall increase in fluctuation, both within and between the years. They also related global satellite measures of vegetation greenness to climate factors to reveal that variation in precipitation is a significant controlling factor of global vegetation productivity. Not only this but in their observations, researchers found that areas with high variation of precipitation support lower livestock densities than less-variable regions.

Map of changes in between-year precipitation variability
This map shows the changes in between-year variability. Of the total land area considered pasture in this analysis, 20% did not experience significant changes (in gray), while 31% experienced significant decreases, and 49% experienced significant increases in precipitation variability.
Credit: Nature Climate Change

With this information researchers were able to assess the risks to places where livestock grazing is important to local food security by using global data sets for percent pasture area and market influence to “define areas in which livestock grazing may play a more or less important role in local food availability or the economy.” These findings exhibit how grazing is extremely vulnerable to the potential effects of climate change, which may put the millions of people dependent on livestock for food security at risk.

The researchers concluded that changes in precipitation variability may cause a change in the composition of certain ecosystems and may also threaten the maintenance or expansion of livestock production. However, the impacts of climate change on livestock grazing will not only depend on precipitation variation but also on region, long-term precipitation trends, changes in the timing of snowmelt, the magnitude of precipitation events, and the changes in seasons. With global grazing lands experiencing 25% more year-to-year variability in precipitation than the average global surface land area, the impacts of climate change on these regions could be detrimental to both the livelihoods of humans and the environment overall.

Lindsey L. Sloat, James S. Gerber, Leah H. Samberg, William K. Smith, Mario Herrero, Laerte G. Ferreira, Cécile M. Godde, Paul C. West. Increasing importance of precipitation variability on global livestock grazing landsNature Climate Change, 2018; DOI: 10.1038/s41558-018-0081-5

Reading Bones: How Ocean Acidification Affects Coral Reef Health

coral reef
Credit: flickr

Climate change impacts everything around us, from weather to the land, air, and water itself. Due to the rise of carbon dioxide in the atmosphere, ocean acidification levels are rising, which in turn threatens the health and wellbeing of coral reef ecosystems. A study was recently published on how ocean acidification directly affects the health of coral reefs, which are essential for protecting coastlines, providing a habitat for aquatic life, and assisting in the chemical conversions of carbon and nitrogen fixing that are essential for life on earth.

A research team at Woods Hole Oceanographic Institute in Massachusetts published a study on January 28, 2018 that identifies the specific way various coral species is affected by ocean acidification and display the effects of future environment conditions on reefs.  They determined that ocean acidification hinders growth of coral skeleton in the thickening process, which in turn reduces the skeleton’s density and leaves it more vulnerable to breakage.

While it had been theorized that coral calcification rates decline as ocean acidification increases, these predictions hadn’t been consistent in a laboratory setting or when studying corals inhabiting reefs with low pH levels. The WHOI was able to study coral skeletons and determine how pH levels and carbonate ion concentrations effect coral reefs and create a mathematical model that predicts how skeletal density will be effected by climate change and ocean acidification in the 21st century. This research plays an important role in examining the impact we have on the world around us and how human actions will effect ecosystem’s future health.

The team took core skeletal samples of Porites, a common coral, from four locations all over the world where sea water conditions vary in pH level and carbonate ion concentrations. Using a 3-D computerized tomography scanner to image the cores, the researchers found annual growth bands on the skeletons (similar to the growth rings of trees) that imply the skeletons of coral in more acidic environments were significantly thinner.

After developing a numerical model that modeled the growth mechanism of coral skeletons and comparing it to projected changes in ocean acidity caused by climate change, the researchers concluded that declines in coral skeletal density will occur in coral reefs all over the world. The Indo-Pacific region in particular will be greatly impacted; it has been predicted that there will be up to 20% in reductions in skeletal density by 2100. This in turn will affect the overall health of coral and the ecosystems coral provides for a vast array of marine life.

Ocean acidification does not happen in isolation and other environmental effects caused by climate change will inevitably also affect the health of these important ecosystems.


Mollica, N.R., Guo, W., Cohen, A.L., Huang, K.F., Foster, G.L., Donald, H.K., and Solow, A.R. 2018. Ocean acidification affects coral growth by reducing skeletal density. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas. 1712806115