Posts filed under Environment (53)

January 18, 2016

Meet Statistics summer scholar Oliver Stevenson

Oliver StevensonEvery summer, the Department of Statistics offers scholarships to a number of students so they can work with staff on real-world projects. Oliver, right, is working on visualising conservation data with Associate Professor Rachel Fewster. Oliver explains:

“This summer project is called Maps, graphs, and data analysis for community conservation projects, and builds on my Honours project from the past year. It involves developing interactive applications that automate the display of catch data from various conservation projects around New Zealand.

“The aim of this project is to allow volunteers to engage with their data in more depth than ever before. After a day in the field, a conservation volunteer is able to go online and use these applications to produce maps or graphics to view their day’s work. The graphics illustrate exactly how a volunteer’s work is impacting their local environment and will ideally keep them motivated to continue with what they are doing.

“I graduated from the University of Otago in 2014 with a Bachelor of Science majoring in Statistics and minoring in Psychology, before completing an Honours degree in Statistics at the University of Auckland in 2015. In 2016, I plan on pursuing a Master of Science in statistics, completing this degree as a research masters.

“I enjoy statistics due to its numerous applications. Nowadays, data exists in almost every facet of life, and wherever there is data, we can use statistics to try and gain a deeper understanding of what is really going on around us.

“In my spare time this summer, I will, hopefully, be able to watch the Black Caps as they continue with their summer of cricket.”

 

 

January 15, 2016

Meet Statistics summer scholar Hubert Liang

Every summer, the Department of Statistics offers scholarships to a number of students so they can work with staff on real-world projects. Hubert, right, is working on ways to graphically represent community conservation effHubert Liangorts with Associate Professor Rachel Fewster. Hubert explains:

“Conservation efforts are needed to protect the natural flora and fauna of our beautiful country. This exciting project involves preparing and analysing data collected from volunteers involved in conservation efforts against pests such as rats.

“The data is analysed and uploaded to a website called CatchIT, which is an interactive website that allows the bait and trap information to be presented in graphic form to volunteers, which provides feedback on their pest-control efforts. The data comes to life on the screen, and this engages current and future volunteers in tracking the success of their pest-control projects.

“I am in the final year of my Bachelor of Science majoring in Statistics and Biological Science, having previously finished a Bachelor of Pharmacy (Hons). Statistics has a wide applicability to a wide range of disciplines, and appeals to me because I am passionate about the simple process of getting the most from raw data. It is a very rewarding process knowing that you can make the data more appealing and important to the end user.

“This summer, besides doing this studentship, I’ll be enjoying the sunshine, and relaxing on the beach with family and friends.”

 

December 25, 2015

Temperature anomalies

The northern hemisphere is warmer than usual this Christmas, as you may have heard. To be precise, it’s about 1 Fahrenheit degree above the 1979-2000 average after seasonal adjustment. (via)

Parts of the northern hemisphere are a lot warmer than that, including many parts that have a concentration of news media with a seasonal shortage of stuff to report. It’s hot in the eastern US, and this quite reasonably gets more reporting that it being cold in Siberia.

GFS-025deg_WORLD-CED_T2_anom

When the US northeast has unusually cold or snowy periods in winter, you see lots of people carefully explaining how this is weather or short-term variation and doesn’t tell you much about long-term climate patterns.

I’m one of those people, so this year I’m making the same point about warm weather.  The northern hemisphere as a whole is warm by about what the well-known trend suggests. The strong El Niño causing weird local weather in the eastern US could definitely be due in part to the global trend, but conclusions about regional variation are much less reliable than conclusions about this CO2 stuff being a bit of a worry.

Like the snow last year, the hot Christmas this year is consistent with climate change predictions but doesn’t add importantly to the evidence. It’s dramatic that Baltimore is as warm as Auckland this Christmas, but compared to the mass of accumulated evidence on the subject, a few days freak weather in a small part of the world just doesn’t mean much.

May 31, 2015

Of droughts and flooding rains

Australia’s climate is weird, even in the relatively habitable bits such as Melbourne, so it makes for interesting graphs. This is going to be another post about aspect ratios and alignment in graphs and how to use them for things other than lying with statistics. (more…)

April 7, 2015

Evils of Axis

First, from Mother Jones magazine, via Twitter

oz-carbon-emissions4

The impact of the carbon tax looks impressive, but this is a bar chart — it starts at zero and they’ve only shown the top fifth of it.

They do link to the data, the quarterly Greenhouse Gas Inventory update.  In that report, Figure 8 is

ozcarbon-line

The dotted line is the same data as the bar chart, except that the dotted line has data for every quarter and the bar chart has data only for the July-September quarter each year. And  the line chart has a wider range on the vertical axis — it doesn’t go down to zero, but it isn’t a bar chart, so it doesn’t have to. The other point about the line chart is that there’s a solid line there as well. The solid line is adjusted for seasonal variation and weather. If you wanted to know about real changes in how Australians are using energy, that’s the line you’d use.

 

Second, a beautiful map of CO2 emissions from fossil fuel combustion, from the Washington Post via Flowing Data

co2map

The ‘vertical’ scale here is a colour scale; what’s misleading is that it’s a logarithmic scale. The map makes it look as if a large fraction of CO2 emission comes from transporting stuff through empty areas, but the pale beige indicates emissions thousands of times lower than in the urban/suburban areas. Red ink isn’t anywhere close to being proportional to CO2.

March 19, 2015

Model organisms

The flame retardant chemicals in your phone made zebra fish “chubby”, says the caption on this photo at news.com.au. Zebra fish, as it explains, are a common model organism for medical research, so this could be relevant to people

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On the other hand, as @LewSOS points out on Twitter, it doesn’t seem to be having the same effect on the model organisms in the photo.

What’s notable about the story is how much better it is than the press release, which starts out

Could your electronics be making you fat? According to University of Houston researchers, a common flame retardant used to keep electronics from overheating may be to blame.

The news.com.au story carefully avoids repeating this unsupported claim.  Also, the press release doesn’t link to the research paper, or even say where it was published (or even that it was published). That’s irritating in the media but unforgivable in a university press release.   When you read the paper it turns out the main research finding was that looking at fat accumulation in embryonic zebrafish (which is easy because they are transparent, one of their other advantages over mice) was a good indication of weight gain later in life, and might be a useful first step in deciding which chemicals were worth testing in mice.

So, given all that, does your phone or computer actually expose you to any meaningful amount of this stuff?

The compounds in question, Tetrabromobisphoneol A (TBBPA) and tetrachlorobisphenol A (TCBPA) can leach out of the devices and often end up settling on dust particles in the air we breathe, the study found.

That’s one of the few mistakes in the story: this isn’t what the study found, it’s part of the background information. In any case, the question is how much leaches out. Is it enough to matter?

The European Union doesn’t think so

The highest inhalation exposures to TBBP-A were found in the production (loading and mixing) of plastics, with 8-hour time-weighted-averages (TWAs) up to 12,216 μg/m3 . At the other end of the range, offices containing computers showed TBBP-A air concentrations of less than 0.001 μg/m3 . TBBP-A exposures at sites where computers were shredded, or where laminates were manufactured ranged from 0.1 to 75 μg/m3 .

You might worry about the exposures from plastics production, and about long-term environmental accumulations, but it looks like TBBP-A from being around a phone isn’t going to be a big contributor to obesity. That’s also what the international comparisons would suggest — South Korea and Singapore have quite a lot more smartphone ownership than Australia, and Norway and Sweden are comparable, all with much less obesity.

February 3, 2015

Meet Statistics summer scholar Daniel van Vorsselen

Every year, the Department of Statistics offers summer scholarships to a number of students so they can work with staff on real-world projects. Daniel, right, is working on a project called Working with data from conservation monitoring schemes with Associate Professor Rachel Fewster. Daniel explains:

Daniel Profile Picture“The university is involved in a project called CatchIT, an online system that aims to help community conservation schemes by proving users with a place where they can input and store their data for reference. The project also produces maps and graphics so that users can assess the effectiveness of their conservation schemes and identify areas where changes can be made.

“My role in the project is to help analyse the data that users put into the project. This involves correctly formatting and cleaning the data so that it is usable. I assist users in the technical aspects relating to their data and help them communicate their data in a meaningful way.

“It’s important to maintain and preserve the wildlife and plant species we have in New Zealand so that future generations have the opportunity to experience them as we have. Our environments are a defining factor of our culture and lifestyles as New Zealanders and we have a large amount of native species in New Zealand. It would be a shame to see them eradicated.

“I am currently studying a BCom/BA conjoint, majoring in Statistics, Economics and Finance. I’m hoping to do Honours in statistics and I am looking at a career in banking.

“Over summer, I hope to enjoy the nice weather, whether out on the boat fishing, at the beach or going for a run.”

 

 

 

 

January 8, 2015

Climate trends

From an interview with Robert Simmons, a data visualisation designer specialising in environmental data, this graph was created by Chloe Whiteaker (at Bloomberg) working with NASA’s Gavin Schmidt. It shows a thirty-year global temperature trend centered around each year.

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If you just plotted the central point of each line segment you’d have a ‘local linear smoother’, one of the standard ways of drawing a smooth curve through a set of data. Plotting the whole line segment makes it clearer how the curve is computed.

(via Alberto Cairo)

 

August 22, 2014

California drought visualisation

 

From XKCD. Both the data and the display technique are worth looking at

california

 

Presumably you could do something similar with New Zealand, which is roughly the same shape.

May 21, 2014

Sea rise visualisation

A new map to let you see the impact of rises in sea levels on your area: this is Auckland with 13m sea rise

flood

 

This doesn’t show the impact of storm surges, which are the big problem for a lot of eastern coastal Auckland (though not so much for Manukau Harbour).

(via everyone on twitter)