Cool interactive maps of deforestation, reforestation, etc.

Hi all,

I just happened across this recent publication in the journal Science: 

High-Resolution Global Maps of 21st-Century Forest Cover Change

1. M. C. Hansen1,*, 
2. P. V. Potapov1, 
3. R. Moore2, 
4. M. Hancher2, 
5. S. A. Turubanova1, 
6. A. Tyukavina1, 
7. D. Thau2,
8. S. V. Stehman3, 
9. S. J. Goetz4, 
10. T. R. Loveland5, 
11. A. Kommareddy6, 
12. A. Egorov6, 
13. L. Chini1, 
14. C. O. Justice1,
15. J. R. G. Townshend1
16. 1. 
       

http://www.sciencemag.org/content/342/6160/850

Here's the abstract, if you don't want to click-through:
Quantification of global forest change has been lacking despite the recognized importance of forest ecosystem services. In this study, Earth observation satellite data were used to map global forest loss (2.3 million square kilometers) and gain (0.8 million square kilometers) from 2000 to 2012 at a spatial resolution of 30 meters. The tropics were the only climate domain to exhibit a trend, with forest loss increasing by 2101 square kilometers per year. Brazil’s well-documented reduction in deforestation was offset by increasing forest loss in Indonesia, Malaysia, Paraguay, Bolivia, Zambia, Angola, and elsewhere. Intensive forestry practiced within subtropical forests resulted in the highest rates of forest change globally. Boreal forest loss due largely to fire and forestry was second to that in the tropics in absolute and proportional terms. These results depict a globally consistent and locally relevant record of forest change.

What's cool about this is that the authors produced an interactive map of forest cover change from 2000-2012:
http://earthenginepartners.appspot.com/science-2013-global-forest

I especially enjoyed looking at the case studies: see "Example Locations" in the bottom right and then click on "Zoom to area". It's in tiny print, but in the very bottom right is a description of what you're looking at as you zoom in on the example locations. 

I think the key point above is that although in places like the Amazon, there is less deforestation, there is still plenty of carbon being released by deforestation in other places (like Indonesia, etc as described in the abstract above). There is some forest re-growth, but not enough to offset what is being cut down, presently. 

Enjoy playing with maps!
Sarah

Americans used less energy 2012

Hi all,
Here's what I was referring to today in class:
http://thinkprogress.org/climate/2013/10/22/2814191/carbon-dioxide-emissions-energy-drop-2012/

"The drop in 2009 was largely due to the contraction in the U.S. economy during the Great Recession, yet the falling carbon dioxide emissions in 2012 occurred while GDP rose 2.8 percent. Energy consumption fell by 2.8 percent."

Which part of the I=PAT equation must have changed, then? The next paragraph gets at it:
"The main reason for this is that American energy intensity dropped — energy use per dollar of GDP fell 6.5 percent. The economy was able to do more with less energy, which has been a long-term trend ever since an inefficient high in 1970."

An important thing to note, though, is that this is ONLY the emissions from energy use. We have a lot of other emissions (e.g., from land use change, agriculture, etc), that aren't accounted for in this analysis. 
Enjoy,
Sarah

For a follow-up to our discussion of the courts and climate change, a group of students at the University of Alaska-Anchorage are suing the state of Alaska for failing to address climate change adequately. See more details here:
http://thinkprogress.org/climate/2013/10/04/2726421/student-sue-alaska-climate-change/

Is population growth a problem? THE problem?

Is a growing population at odds with a sustainable future? It's an old debate, and one that hasn't lost its power to arouse. Here's the latest iteration, with a letter in the New York Times entitled "Overpopulation is not the Problem." In it, geographer Erle Ellis concludes:

"There is no environmental reason for people to go hungry now or in the future. There is no need to use any more land to sustain humanity — increasing land productivity using existing technologies can boost global supplies and even leave more land for nature — a goal that is both more popular and more possible than ever. The only limits to creating a planet that future generations will be proud of are our imaginations and our social systems. In moving toward a better Anthropocene, the environment will be what we make it."


Of course, there are several letters in response, posted here. A trio of noted sustainability scholars (Clark, Schrag, and Cohen) responds: 

"Continued rapid human population growth makes it harder and more costly to solve all our problems. The institutional, technological and behavioral innovations that have a chance of leading to the rosy future Mr. Ellis envisions will happen only with substantial effort and investment, and will be easier with slower or no population growth."

More pithily, the UA's Alan Weisman replies that Ellis's assertion about no need for hunger
"must be comforting to the planet’s billion-plus hungry people."

More followup, including a deeper explanation of the author's perspective, is available on the Dot Earth blog here and here. 

What do YOU think?

Why has average global temperature flattened out?

Some of you may have noticed that global temperatures appear to have stopped increasing over the last decade or so. The Yale Forum on Climate and the Media has a good summary post as to why:

http://www.yaleclimatemediaforum.org/2013/09/examining-the-recent-slow-down-in-global-warming/

The article breaks down "global" temperature into its components - like land surface temperature, ocean surface temperature, and shows the data and temperature trends for each component. It also investigates natural variability in the climate system that could be contributing to the recent flatness.

Basically, natural variability is masking a lot of the human-caused change over the past decade. There's more to it than that, including things we'll talk about like other places that are taking up the heat (like the deep ocean), but that's one piece of the puzzle. The article is a little dense with info, but if you're interested, check it out!

Other variables that affect global sea level: extreme rains in Australia!

Hi all,
It turns out that melting ice and thermal expansion are not the only important factors for sea level change; the amount of rain over land vs. ocean also can be.

In this case, extreme rains over Australia during 2010-2011 pooled at the center of the continent and caused global sea level to drop (temporarily). For more info on this, check out the story on NPR:

http://www.npr.org/2013/08/20/213577129/how-extreme-australian-rains-made-global-sea-levels-drop?ft=1&f=1025

Here's a link to the original article by Fasullo et al. in Geophysical Research Letters (subscription required - access this from a computer logged onto the Arizona library system and you should be able to get it):

http://onlinelibrary.wiley.com/doi/10.1002/grl.50834/abstract

Enjoy!
Sarah

IPCC leak: manmade climate change really real

IPCC report leaked....

One of the stories we will be following right away is the upcoming release of the report on climate science by the Intergovernmental Panel on Climate Change (IPCC). This group painstakingly summarizes the latest in climate science every 5-6 years, and provides a summary for governments, policymakers, and other interested parties. It's the gold standard of climate science - a synthesis of peer-reviewed science, prepared and reviewed by a cast of hundreds (thousands?) of experts.

A near-final version of this report was leaked last week and many of its major conclusions have been spread across the web. These stories provide a summary:

The New York Times: 
http://www.nytimes.com/2013/08/20/science/earth/extremely-likely-that-human-activity-is-driving-climate-change-panel-finds.html?pagewanted=all

See also The Week, Mother Jones, and the Washington Post's Capital Weather Gang page. 

If any of these reports strikes you as overly alarmist, then check out a recent paper by Naomi Oreskes and colleagues (Brysse et al. 2012) which details how the IPCC errs on the "side of least drama"  - i.e., it is a conservative interpretation, because scientists are cautious people. Things will likely be worse.

Another paper (Rahmstorf et al. 2012) compared IPCC projections of future temperature and sea level with observations - they find that the IPCC consensus underestimated future sea level change dramatically, but was reasonably accurate in their temperature projections.

Welcome to Global Change!

Welcome to Global Change!

We'll use this space to highlight global change topics in the news, or new scientific results that we think are especially interesting for class. 

Everyone in class is welcome to post and comment - we will work out the mechanics of this during the first week. The blog will be publicly visible, but comments and posting are limited to class members. 

Welcome!