Anthropogenic biomes

A post by Anne JeffersonChris is not the only one who comes across fascinating things via Twitter. Just yesterday I was introduced to the concept of anthropogenic biomes. In physical geography, biogeography, and ecology classes we learn and teach about biomes – major global ecological communities, classified according to the dominant natural vegetation. But more than 3/4 of the world’s ice-free land shows the evidence of human activity – and the remaining 1/4 of the planet supports just 11% of the Earth’s terrestrial net primary production. Recognizing these things, Erle C Ellis and Navin Ramankutty of University of Maryland-Baltimore County and McGill University, respectively, have recently advanced the idea of anthropogenic biomes that characterize the human-altered landscape. Their new view of the world is shown below:
anthrome_map_v1.jpg

Click on the image for a much larger, readable version.

Ellis and Ramankutty argue that “anthropogenic biomes are in many ways a more accurate description of broad ecological patterns within the current terrestrial biosphere than are conventional biome systems that describe vegetation patterns based on variations in climate and geology” because such natural patterns are rarely found in large areas outside of the wildland anthropogenic biomes. A few highlights from this view of looking at the world:

  • 40% of humans live in dense settlements biomes, 40% live in village biomes (38% urban), 15% live in cropland biomes, 5% live in rangeland biomes, and 0.6% live in forested biomes
  • dense settlements and villages cover 7% of the Earth’s ice-free terrestial area
  • village biomes (dense agricultural populations) cover 1/4 of the Asian continent
  • “anthropogenic biomes are best characterized as heterogeneous landscape mosaics, combining a variety of different land uses and land covers”
  • wildland biomes are found in the least productive areas on Earth

You can read more about this concept in their 2008 Frontiers in Ecology paper (pdf here) and on their website. You can even print a wall map, or play with the data in Google Earth or ArcGIS. I think anthropogenic biomes are a pretty neat concept and next time I teach my introductory earth science course, I’m going to use them to better tie the required chapter on biomes together with the big themes of the class. What do you think? Is this a useful concept? Or at least a pretty map to look at?

Categories: environment

Book Review: Field Notes from a Catastrophe

Elizabeth Kolbert’s “Field Notes from a Catastrophe: Man, Nature, and Climate Change” was published in 2006, and it’s been on my to-read list since Bootstrap Analysis reviewed it in April of that year. Last winter at AGU, I finally procured my own copy, and I’d read and thoroughly enjoyed the book by the time my plane touched down. Now I finally have an excuse to add my own review to the chorus of praises for the book.
Though the scientific story of anthropogenic global warming is familiar to many of us, Kolbert’s book is still an excellent read. And for those unfamiliar with the causes and consequences of on-going climate change, Kolbert’s book is an essential read. I dare you to read this beautifully written book and not find yourself wandering around the house, book in hand, unplugging electronics and turning off lights.
In the first part of the book, the book focuses on the on-going and projected impacts of climate warming on natural systems – glaciers, permafrost, butterflies, and toads. The author provides just enough clearly-explained scientific details to make sure that all of her readers can appreciate the profound consequences of global warming. In the second part of the book, Kolbert focuses on the consequences of climate change for our species. One of the most memorable chapters of the book chronicles the Dutch attempts to deal with rising sea levels in their low-lying country by reclaiming farmlands for floodplains and even building floating houses.
One of the things I like most about this book, other than the beautiful writing, is that Kolbert spends a signficant amount of space taking her readers through the options we have for mitigating climate change – everything from the Dutch floating houses, to giant solar panels in space, and the idea of stabilization wedges. She doesn’t pretend it will be easy to avoid the on-coming catastrophe, but she doesn’t adopt a fatalistic attitude either. Kolbert takes us to Burlington, Vermont, where voluntary local actions, spearheaded by an energetic mayor, have succeeded in reducing the city’s energy usage by 1% over a 16 year period, while the rest of the state’s usage has increased 15%. But a few pages later, Kolbert reminds us of that China plants to build 150 new 1000 megawatt coal-fired power plants by 2010. Clearly, changing the global emissions trajectory cannot just be the responsibility of individual actions in liberal, well-off communities.
My only gripe with the book is a minor one. The chapter called “The Day after Kyoto” already feels a bit dated and clearly a product of its time – contemporaneously with Gore’s An Inconvenient Truth and the aftermath of Hurricane Katrina. This chapter details the Bush administration’s and others’ efforts to to sabotage international attempts to reduce greenhouse gas emissions and to create doubts in the public mind as to the scientific consensus around human-influence climate change. While such chronicling of political misdeeds is certainly important, I felt like this chapter could turn off the very audience this book should be trying to reach – those who haven’t quite made up their mind as to whether climate change is serious and whether we have anything to do with it. Elsewhere I’ve read that such people make up about 1/3 of the US adult population.
Overall though, Elizabeth Kolbert’s “Field Notes from a Catastrophe” is a compelling and evocative reminder of the impacts of anthropogenic global warming on nature and humans. Next on my list to read is Dianne Dumanoski’s “The End of the Long Summer: Why We Must Remake Our Civilization to Survive on a Volatile Earth.” That seems like an appropriate title to begin on this Labor Day back-to-school holiday, but Dumanoski has a tall order to stack up against the joy to read of Field Notes from a Catastrophe.

Categories: by Anne, climate science

Stuff I linked to on Twitter last week

One of the main things I do on Twitter is link-sharing: that is, note stories and web resources that I find interesting, but that I don’t have the time or inclination to blog about (my own idiosyncratic approach to blogging has always generally boiled down to, “some thought/input from Chris required”). It works well for me, but I know that not everyone who reads the blog is into Twitter; that, and the desire to keep a more permanent record of stuff I’ve encountered on the interwebs, has led me to wondering if it would be worth posting a weekly summary. Which is what you see below: all of my tweets last week where I linked to something I found interesting, shorn of all the @s and RTs.
Sediments can be as pretty as minerals sometimes: see Clastic Detritus’ Friday Field Foto from Tierra del Fuego http://bit.ly/g2hfa
Wonder what hoaxers thiink? Apollo 12 landing site (+ visible astronaut footprint tracks!) imaged by LRO: http://is.gd/2RiYv
WANT. Like beer? Like the Burgess Shale? Combine them! http://bit.ly/Mzzqg
Rock and Roll Building Will Survive Earthquakes http://bit.ly/n8WKL
Mentioning geoengineering could spur people to reduce their carbon footprint. http://bit.ly/yE8WE
A glass act: sculptures of deadly viruses http://bit.ly/drAsD
Did Life Arise 3.5 Billion Years Ago? http://tinyurl.com/kv9axl
24 hr global animation of scheduled flights. Fascinating! http://bit.ly/WBDY
How depressing. Exclusive: Chances of getting a (UK) research grant plummet to all-time low. http://bit.ly/1OSfQr
Oooh: anectodal report that Iphone can accurately measure diips and strikes http://bit.ly/10oiAr Structural mapping app, anyone?
A great discussion about different types of basin http://bit.ly/1aYces
Discussion on mainstreaming geo-terminology at All of My Faults are Sress Related gets ever better. Fave so far: Franciscan=disorganised. http://bit.ly/DbOFs
Geobloggers riffing off the LA fires: http://bit.ly/1Yzv1J and http://bit.ly/t8h3c
Completely addicted to StormPulse hurricane monitoring tool. Here’s Jimena: http://bit.ly/2JNlXu
What would you give to geologise on Mars? Should the first manned mission to Mars be a one-way trip? http://bit.ly/PuyQY
Royal Society weighs in on Geoengineering http://bit.ly/2KoDK Seem to think it may be a necessary semi-evil.
Dear science journalists, please stop saying “scientists believe…” http://bit.ly/JHg0k
PG&E wants to store wind, solar energy http://bit.ly/VUqDl As compressed air pumped into porous reservoir rock. Clever.
Let me know whether you think this is useful or interesting; if enough people like, I’ll make it a regular weekend thing. Please don’t be afraid to tell me you find it annoying; I’ll just keep a personal record and leave it at that.
While you’re possibly feeling opinionated, please also take a second to go and tell the Overlords what you’d like from their proposed user registration programme.

Categories: bloggery, links

Lots of oxygen on the Archean Earth?

ResearchBlogging.orgMost geological evidence indicates that significant amounts of oxygen only began to accumulate in the Earth’s atmosphere and oceans during a ‘Great Oxygenation Event’ at the beginning of the Proterozoic, between 2.3 and 2.4 billion years ago. However, distinctive organic biomarkers found in 2.7 billion year-old sediments in northwest Australia [1] indicate that the ultimate source of all that oxygen, photosynthetic cyanobacteria, first emerged at least 300 million years before the Great Oxygenation Event; and if oxygen producers apparently laid low for that long without apparently making much of a mark on the Earth’s atmosphere, it’s possible that they could have emerged even earlier in the history of our planet – which is exactly what evidence published a few months ago Nature Geoscience might suggest. The authors claim that minerals in Archean chemical sediments from the same part of northwest Australia precipitated from oxygenated seawater; if they’re right, this would potentially push the emergence of photosynthesis back another 700 million years, to almost 3.5 billion years ago.
Masamichi Hoashi and his colleagues have closely examined iron minerals in the Marble Bar Chert, from the Warrawoona Group of the Pilbara Craton. The stratigraphic column below (adapted from [2]) shows that this sequence has yielded a number of other controversial claims about early life, including the oldest known “stromatolites”, which may or may not have been inorganically precipitated (see [3] and subfigure b below), and, even more contentiously, putative bacterial microfossils (subfigure a – see [4] and [5] for pro- and anti-bacterial views, respectively).

Pilbarastrat.png
Warrawoona Group, Pilbara Craton, NW Australia

The silica that makes up the bulk of the Marble Bar Chert is peppered with iron minerals.

Marble Bar Chert in outcrop
The upper part of the Marble Bar Chert; the red stripes are rich in the iron oxide haematite

Continue reading

Categories: Archean, geochemistry, geology, paper reviews, past worlds, rocks & minerals

Last call for women geoscientists reading or writing blogs to take our Survey

The GSA meeting is ~6 weeks away – it must be time to start trying to make sense of the data, right? I’m helping Kim, Zuska, and Pat with a survey of women geoscientists and how they use blogs, and we need to finish collecting our data and start analyzing. We’ve gotten a great response so far, but if you haven’t taken our survey yet, here’s your last chance. We’ll close the survey on Monday, September 7th.

Over the past several years, the geoscience blogosphere has blossomed so much that this fall, the Geological Society of America (GSA) will be convening a Pardee Keynote Symposium called “Google Earth to Geoblogs: Digital Innovations in the Geosciences.” Kim Hannula started wondering how blogs serve women geoscientists. Kim recruited the rest of us and we decided to approach this problem as scientists – by collecting data and analyzing the results. Specifically, we’d like to know how blogs might help in the recruitment and retention of women and minorities. We plan to discuss our results at the GSA session on “Techniques and Tools for Effective Recruitment, Retention and Promotion of Women and Minorities in the Geosciences.” We have designed a survey, gone through the Institutional Review Board process (completely foreign to us geologists), and now we need help from you.
We are asking you to complete a short (5- 10 mins), anonymous, survey. The survey focuses on your participation with science blogs, why you read science blogs and what you gain from reading science blogs. It will also ask you to list blogs you find to be particularly useful and a little about yourself. No questions are required, all are optional. We are primarily interested in the responses of women and minority geoscientists, but non-minority men, please feel free to fill out the survey as well. Your answers will be a useful point of comparison. Note also that we are definining geosciences rather broadly. If you are or can be a member of GSA, AGU, AAG, AMS, ASLO, their international counterparts, or similar organizations, please consider taking the survey.
All the data collected are anonymous and no individuals can or will be identified. Your participation in this study is completely voluntary. You are free to withdraw at any time without having any negative affect. If you have questions concerning the study, please contact Dr. Anne Jefferson at ajefferson (at) uncc (dot) edu.
To start the survey, just click here.
Sincerely,
Anne Jefferson
Kim Hannula
Pat Campbell
Suzanne Franks

Categories: academic life, bloggery, by Anne