New studies deepen concerns about a climate-change ‘wild card’

A recently published Washington Post article entitled “New studies deepen concerns about a climate-change ‘wild card’” references two published studies. In the Washington Post article the author reports that future climate change will lead to disruptions in global ocean currents. Specifically, the weakening of the Atlantic Meridional Overturning Circulation (AMOC) system is discussed. This circulation system is responsible for transporting warm water northward, and cold, dense saltwater down into the deep ocean. The water circulation pathway helps to keep temperatures moderate in Europe.

One of the referenced studies, entitled “Response of Atlantic overturning to future warming in a coupled atmosphere-ocean-ice sheet model”, uses computer modeling to study the effects of rapid thawing of Greenland’s ice sheets. The study is published in Geophysical Research Letters and explores the AMOC’s sensitivity to changes in ocean temperature and freshwater perturbations. Previous studies have been conducted to explore Greenland ice sheet (GIS) melting, however, this study incorporates a new modeling technique that more accurately predicts the effects of freshwater incorporation into the AMOC system. The new modeling technique predicts more dramatic changes than previously expected from previous modeling techniques. The dynamic ice sheet model predicts weakening of the AMOC, and describes the intensification of the high-latitude halocline as a result of the freshwater discharge into the North Atlantic by GIS melting. Furthermore, the salinity decrease of the upper layer water inhibits North Atlantic Deep Water (NADW) due to the fact that freshwater is less dense than fresh water.

Figure 2 shows changes in salinity in the North Atlantic as a result of the GIS melting modeling. The dynamic modeling predicts a decrease in practical salinity by 2 units, while previous modeling systems predicts a decrease in practical salinity by 1 unit. This figure highlights what previous modeling systems failed to take into account.

   

The other referenced study, entitled “gradual onset and recovery of the Younger Dryas abrupt climate event in the tropics”, discusses the Younger Dryas (YD), a rapid climate change event that occurred 12.5 thousand years ago, also known as the Big Freeze. In this study published in Nature Communications, they use modeling to study this major past geological event to make predictions on future climate events. The current hypothesis for the cause of the YD is that a rapid freshwater influx into the North Atlantic weakened the AMOC and induced the abrupt climate change. In the paper, modeling using new hydroclimate records from the tropics is combined with previous established hydroclimate data to make future climate event predictions. Overall, much of the data reported in this study is analysis of the past. I think this paper was referenced to show an extreme example of global climate change (the YD), and the potential extreme implications of a weakening AMOC.

In short, both studies use modeling to predict weakening of the AMOC as a result of global climate change, which leads to predictions for future weather patterns and climate. They both use newer modeling systems to add to previously established research. I think overall the popular media article overhyped the reported research by using phrases such as “dramatic implications” and making references to movies such as “Day After Tomorrow”. Furthermore, I think when they claim that “possible effects [range] from plunging temperatures in the northern latitudes to centuries-long droughts in Southeast Asia” is a severe over-exaggeration of the reported research. The article also claims that global climate change may lead to the “shut down” of the AMOC, while the scientific articles report a weakening of the AMOC. However, when the scientific papers are described in the Washington Post article, I think the research was well summarized (though very briefly) and it is clearly mentioned that computer modeling was involved. Quotes from the authors of the peer-reviewed papers were included in the Washington Post article, which allowed for a more dramatic spin on the reported research. 

Popular media article:

http://www.washingtonpost.com/news/energy-environment/wp/2015/09/07/new-studies-deepen-concerns-about-a-climate-change-wild-card/

Peer-Reviewed articles:

http://onlinelibrary.wiley.com/doi/10.1002/2015GL065276/full

http://www.nature.com/ncomms/2015/150902/ncomms9061/full/ncomms9061.html

Study Predicts Antartica Ice Melt if All Fossil Fuels Are Burned

Despite the debate surrounding the existence of climate change, it is most definitely happening. One of the most pronounced effects of climate change has been sea level rise due to the melting of masses of ice around the world. The Antarctic Ice Sheet stores enough water to rise the global sea level by 58 meters and some scientists, as in the study that this news article is based on, believe that by burning the remainder of the Earth’s fossil fuels, the ice sheet will be eliminated and the sea level will make this 58 meter rise. 

The New York Times published a news article based on a paper published in Science Advances by scientists from Germany, the UK and California. The Times article summarizes the key points from the research article in that is goes into detail about how the sea level rise would occur and what areas would be greatly affected. The author of the Times article even goes as far as collecting statements from some of the researcher on the paper and including the personal quotes in the article. The article then takes a political detour, discussing the lack of effective political action taken in the past 30 years and the possible actions of President Obama and his opposition within the Republican Party. The article does mention that this study was based on a model but does not go into enough detail about the study’s actual methods to point out that this is only calculated data. The article ends with some text on the history of seal level rise awareness and the great negative impacts we make by burning fossil fuels leading to, ultimately, the end of the world as we know it. It is interesting that the author closes the article with a statement from a researcher not involved in the study that brings up the ethics of ignoring a problem that will not affect us in our lifetimes. “What right do we have to do things that, even if they don’t affect us, are going to be someone else’s problem a thousand years from now?”

The research article in Science Advances outlines the models and simulations that were performed to determine the rise of global sea level as the ice sheets, specifically the Antarctic Ice Sheet, as more fossil fuels are burned raising oceanic and/or global temperatures. The article states that ice loss is driven by two self-reinforcing types of feedback: the marine ice-sheet instability, which occurs when ocean warming leads to subsequent sub-shelf melting, and the surface elevation feedback, which occurs when a critical temperature is reached, the lower elevation of the ice and increases surface mass loss. The simulations seem to be centered on the levels of CO₂ emitted and correlate this to the melting. There is little to no discussion on the actual chemical reactions that must take place to cause an increase in temperature and also no mention of the ozone hole which would also be a key factor to this loss of ice. The research article makes no mention of further work or investigation and there no mention of any possible solutions to the impending sea level rise.

The Times article seems to utilize the research article as more of an example and spends more time on sensationalizing the topic and including causal remarks from the researchers about their surprise at the results of the simulation. The Science Advances article includes only a reference as to how they determined the total amount of fossil fuels left to burn and does not state that they take into account any information regarding the actual amounts remaining in mining areas or possible storages yet untapped. The comments included from the researchers are of little scientific merit and only impress the point that the researchers were surprised and in disbelief as to how serious the situation is. The lack of explanation or discussion of the reliability of the simulation models is also of concern and leaves room for error or misinterpretation. 

Overall, the Times article brings an important topic to the attention of the public with evidence from a scientific research article which is a positive result. However, the article ignores most of the specific data presented in the paper and instead brings in the political opinions of the author, drastic comments about the future of human existence and unreferenced statements about ice loss and sea level rise.

New York Times Article

http://www.nytimes.com/2015/09/12/science/climate-study-predicts-huge-sea-level-rise-if-all-fossil-fuels-are-burned.html?_r=0

Science Advances 11 Sep 2015:
Vol. 1, no. 8, e1500589
DOI: 10.1126/sciadv.1500589

http://advances.sciencemag.org/content/1/8/e1500589.figures-only

Why Restoring Nature Could Be The Key To Fighting Climate Change

Climate change is a hotly debated topic within the common public but is highly accepted within the scientific communities. The changing climate is causing many regions to warm and also some regions of the world to cool. As a result of this changing climate, there are many impacts to human populations and also to ecosystems. At this point, there are many studies being conducted to predict the future effects of climate change and how best to mitigate the negative effects.

In an article by TIME, author Justin Worland writes about a recent study published in Nature about minimizing negative effects on ecosystems through biodiversity. Justin makes a very intelligent comment that more action is needed in response to climate change than creating regulations that will not have a significant impact until years down the road. Rather than just changing human behavior, he argues, there needs to be movements to resist climate change in the present.

Justin makes an educated summary of the Nature publication giving a brief synopsis of the study and a factual conclusion. In summary, 46 experiments across the northern hemisphere that manipulated grassland plant diversity were measured for productivity after quantified "climate extremes." The study found that productivity from communities with little diversity changed 50% from climate extremes and high diversity communities changed roughly 25% from climate extremes. Justin also stayed true to the original publication and admitted that biodiversity only affected the resistance to climate events and not the overall resilience of the community to recover after the event.

Justin Worland then went on to write about forests absorbing carbon emissions and how adding biodiversity to forests in addition to reversing deforestation trends might allow for absorbing more global carbon emissions. While this conclusion wasn't mentioned in the original Nature publication, the author, Justin, did cite two other studies to verify his own conclusion. Overall, his conclusion seemed based in logic and was not over the top.

Overall, the Time article was very factually accurate and was not oversold. It did a good job connecting multiple studies as well. The peer-reviewed article lived up to the reputation of Nature and was excellent in all aspects. I think this was an interesting concept to consider in regards to climate change. It was also interesting that biodiversity helped ecosystems resist climate change but had no effect on the ability of the ecosystem to rebound after. Both high diversity and low diversity ecosystems were able to make full recoveries after large climate events; perhaps an argument that the Earth is capable of healing itself with time.

Links:
http://time.com/4070683/nature-climate-change/
http://www.nature.com/nature/journal/vaop/ncurrent/pdf/nature15374.pdf

Geomagnetic field can really change climate?

Global warming can impact our agriculture, ecosystems as well as human health. These impacts may lead to significant costs to human beings. In order to avoid potential consequences, many scientists and institutions have been trying to find reasons for global warming. Most climate scientists agree that the main cause of the current global warming is the “greenhouse effect”, i.e. the atmosphere traps heat radiation from the Earth toward space. In addition, there are still some other theories trying to explain global warming. Two Canadian scientists, David Vares and Michael Persinger, published a paper in which they concluded that the global warming and the rise in CO₂ resulted from decreases in the strength of the Earth’s magnetic field instead of CO₂ emissions from burning fossil fuels. Recently a blog article reviewed this paper.

The main point of Vares and Persinger’s paper is that the decrease of Earth’s magnetic field strength can affects the solubility of CO₂ in water. In addition, Vares and Persinger also said that the increasing CO₂ concentration in the atmosphere did not directly result in the global warming. Instead, the energy change associated with the Earth’s changing magnetic filed can cause an equivalent temperature which may be responsible for global warming. The blog author gave some comments on Vares and Persinger’s paper. First the blog article pointed out that the relation between the strength of the Earth’s magnetic field strength and concentration of CO₂ in the atmosphere was just correlation rather than causation. Then the blog author found one 2008 paper which was cited by Vares and Persinger’s paper and used to prove the causal link in their paper actually refuted their own idea that geomagnetism can explain global warming. Finally, the blog also found a significant calculation error in Vares and Persinger’s paper. This means the conclusion made in their paper was completely wrong! Overall, the blog author was very disappointed with Vares and Persinger’s paper.

Actually, two Canadian scientists’ paper was not strong enough to prove their ideas. I think we must be more cautious as scientists or experts in some fields when we write papers or other publications. Even though we should be bold to imagine or make assumptions, we still need to be responsible for what we write to the public.

Link to the blog article

Link to Vares and Persinger’s paper

India Air Pollution Cutting 660 Million Lives Short by 3 Years

An article posted in the Huffington Post comments on the dangerous air pollution in India and the effect this has on life expectancy. They refer to a study published in Economic & Political Weekly that discusses the ambient particulate matter (PM) air pollution in India and how this reduces life expectancy. The Huffington post article talks about PM2.5, which are fine particulate matter pollution with a diameter of less than 2.5 micrometers, small enough to seriously damage the lungs, and that for every 100 micrograms of PM2.5 life expectancy drops by 3 years. The article also discussed the unsafe levels of pollution present in India stating “estimates that 99.5% of India’s 1.2 billion people are breathing in pollution levels above what the WHO deems as safe.”

This is in keeping with the study led by Prof. Greenstone, which discusses in detail how they examined the fine particulate air pollution data set and how they estimated the effects of this pollution on long-term mortality. The study goes into more detail on the air quality standards of India compared to the stricter World Health Organization standards of air quality.

The study also mentions “660 million people (54.5% of the population) live in regions that do not meet the 40 microgram per cubic meter standards and that 21.7% of the population live in regions with air pollution levels at more than twice this standard."

The article also explains the dangerously high air pollution being due to the burning of fossil fuels to grow the economy and pull people up from poverty. India has pledged to boost its clean energy sector but has also increased its coal-fired electricity, which will has serious negative effects on the already polluted air. The news article doesn't include how the study goes on to talk about possible policy reforms that India should implement to improve the pollution and increase the life expectancy while having small costs to the economy.

I think the article did a great job summarizing the key facts of the study without overselling or misrepresenting the information. The fact that the article did not mention the directions for policy reforms that the study discussed did not hurt the article in any way but I thought they were interesting ideas to improve the air pollution of India.

Kids who Breathe More Pollution Have Lower Grades

A child plays near the Valero Oil Refinery in the Manchester
neighborhood of Houston, TX. (Source: Earthjustice)

The link between air pollution and increased respiratory disease in children has been well studied.  There are still questions, however, about how such pollution may impact a child's academic performance. While some studies have looked at the link between air pollution exposure and academic success, these studies have been limited by their resolution, primarily using school-level data which can miss the effects of individual factors, like socioeconomic status or parental education, on school performance.

A new study published in the journal Population Environment looks at this problem at the individual level, and demonstrates a link between exposure to air toxic pollution and a lowering of GPA when controlling for several factors also known to impact school performance.  The study used data from EPA’s National Air Toxics Assessment (NATA), an inventory which estimates concentration of air toxic pollutants, as well as household and school performance information gathered through mail surveys.  Even when controlling for a variety of factors (economic deprivation, mother’s education, age of mother at birth, race/ethnicity and mother’s English proficiency), seven of the eight NATA risk variables were significantly negatively correlated with a child’s GPA. In other words, all other things being equal, children exposed to higher doses of toxic air pollutants will have lower GPAs than their peers.  The online publication, Mother Jones, covered the study in its recent article “Kids Who Breathe More Pollution Have Lower Grades”

In general, the Mother Jones does a good job summarizing the main points of the study and conveying the conclusions of the research.  The final paragraph of the MJ article includes a quote from the study’s author, Sara Grineski: “The finding that there is a significant association between residential exposure to air toxins and GPA at the individual level is both novel and disturbing…these findings provide another piece of evidence that should inform advocacy for pollution reduction…”.  This really is the main point and conclusion of the journal article and MJ does a good job to leave the reader with that sentiment.

The MJ article, however, fails to discuss the limitations of the research. It is really difficult to estimate individual level exposure without direct monitoring and the study’s data sources leave a lot of room for error. The EPA’s assessment of air toxic concentration is based on calculation and modeling, meaning that it is likely a close, but not exact estimate of ambient air toxic concentration. Further, the study assumes that all children living within a census block experience the same exposure, which is also likely untrue.  Concentration at individual houses will be variable due to weather patterns, some children may spend less of their time at home, some may spend more of their time playing outside where they are exposed at higher rates, etc. While the study mentions these limitations, the Mother Jones article does not include information about the data used in the study. Without looking at the original article, the reader would likely assume that the data comes from direct pollution measurements and that exposure estimates for individual children are exact.

The article links to the MJ cover story about a growing body of research linking ultra-fine particle pollution to dementia and Alzheimer’s disease.  While this provides the reader more information about how pollution may impact student’s GPA, it also implies that the journal article demonstrates a clear link between air pollution and lowered neurological function. The journal article only shows that higher exposure is correlated to lower GPA. This could mean that breathing more pollution is directly worsening school performance by impacting cognitive function, but it also could mean that the children are missing more days of school due to other pollution-related illness. By framing this study in terms of the Alzheimer’s work, the MJ article draws a conclusion not demonstrated by the research.

While they don’t get all the nuance of the data, and perhaps go beyond what the study’s authors have proven, the MJ article does a good job presenting the information in an accessible and engaging way and highlights an important area of environmental justice research that ought to be better understood by the general public.

Journal Article: http://link.springer.com/article/10.1007%2Fs11111-015-0241-8

Mother Jones Article: http://www.motherjones.com/blue-marble/2015/08/pollution-lowers-gpa