Here is Saleska’s commentary in full
——-
Guest Commentary by Scott Saleska

The title of the Lewis post (“Up is Down, Brown is Green”) is perhaps even more true than the insightful commentary by my colleague Simon Lewis indicates! The Samanta et al paper says brown, but in fact their own data (when you dig it out of the supplement) shows green, consistent with (and indeed virtually indistinguishable from) our original findings published in Science (Saleska et al., 2007).

Samanta et al. misrepresents our work on many levels (one of which is to assert, falsely, that we did not filter out atmosphere-corrupted observations when in fact we did), and we intend, of course, to present an appropriate response in the peer reviewed literature, where the technical details of our differences may be evaluated by anyone who wishes. But for the moment we will, for the sake of argument, accept their analysis at face value and ask: even if Samanta et al. are 100% correct in their critique of our methods (which we of course dispute), what are the implications? Does the alternative to our method which Samanta et al. advocate, or the recent update in the MODIS satellite data (to version 5 from version 4), make any difference for the main conclusion of our paper? With due respect to our friends and colleagues at Boston University, the answer is no, it does not.

First: the actual relevant Samanta et al data (which comes from their Supplement, Table S3) is this:

Note that the green area in the drought region increases to its maximum (10.8% of the total area = 10.8/33.68 = 32% of the valid area) in 2005. In other words, the Samanta et al data contradict the Samanta et al text and title (which states that Amazon forests did not green up): not only do forests in the drought region green up, they green up alot, more than any other year since the MODIS satellite sensor was launched.

Second, how does this compare to Saleska et al. (2007), which Samanta et al claim to rebut? Here are the numbers (again, taken directly from Samanta et al, Table S3 and Saleska et al., 2007):

Fraction of valid pixels in the 2005 drought region that are “green” (> + 1 Standard deviation)
Saleska et al. (2007): 34% (p<0.000001)
Samanta et al. (2010): 32% (p<0.004)

The bottom line is that their observed 2005 result (32% greenness) is indistinguishable from ours (34%). I.e. Samanta et al effectively reproduce the results of Saleska et al.

This summary response, of course, begs some very interesting questions about tropical forest function under climatic variability and change (indeed the most interesting questions of all!): what caused the anomalously disproportionate green-up in the drought region? And, even if satellite “green up” does in fact represent an increase in photosynthesis (as we think), could this in fact be a symptom of the trees compensating for the increased stress of the drought? The bottom line “carbon balance” of a tree depends on both photosynthetic uptake and respiratory losses, and it is almost certainly the case that those losses (which were not seen by the satellite) increased under the hotter and drier conditions of the drought as well.

Thus, the most intriguing idea to me is that the short-term satellite-detected green-up, and the longer term increase in net carbon loss reported in the Phillips et al paper (discussed by Simon Lewis) are not in conflict at all. It might well be that they represent different parts of a coherent forest response to drought, in which the longer term losses are larger than the satellite-detected attempt to compensate for them by increasing photosynthesis, and in the end, increased tree mortality is the result.

In conclusion I would like to reinforce Simon’s point about Samanta et al and the IPCC. More important than whatever they say about our one short paper, Samanta et al. truly and egregiously misrepresent the implications, of both their work and ours, when they claim that a single paper on short term vegetation response somehow rebuts the IPCC’s review of the large scientific literature on how Amazonia might respond to long-term shifts in the mean climate state. It is an illogical and misguided claim on many levels, one that is already and deservedly attracting the opprobrium of many of my colleagues, talented scientists who study Amazon forests and climate (see Scientists speak: Amazon “myths” are not debunked).

In sum:

– Samanta et al data show a drought region green up that is on average indistinguishable from Saleska et al (but they call it NO green up).
– Samanta et al data almost exactly reproduce Saleska et al’s most salient bottom-line result (but they say what we did was not reproducible).
– the Samanta et al paper, based on a three-month drought response, says not one word about long-term climate change scenarios reviewed in IPCC (but they advertise their analysis as “reject[ing] claims” put forward by the IPCC).

Here is Saleska’s commentary in full
——-
Guest Commentary by Scott Saleska

The title of the Lewis post (“Up is Down, Brown is Green”) is perhaps even more true than the insightful commentary by my colleague Simon Lewis indicates! The Samanta et al paper says brown, but in fact their own data (when you dig it out of the supplement) shows green, consistent with (and indeed virtually indistinguishable from) our original findings published in Science (Saleska et al., 2007).

Samanta et al. misrepresents our work on many levels (one of which is to assert, falsely, that we did not filter out atmosphere-corrupted observations when in fact we did), and we intend, of course, to present an appropriate response in the peer reviewed literature, where the technical details of our differences may be evaluated by anyone who wishes. But for the moment we will, for the sake of argument, accept their analysis at face value and ask: even if Samanta et al. are 100% correct in their critique of our methods (which we of course dispute), what are the implications? Does the alternative to our method which Samanta et al. advocate, or the recent update in the MODIS satellite data (to version 5 from version 4), make any difference for the main conclusion of our paper? With due respect to our friends and colleagues at Boston University, the answer is no, it does not.

First: the actual relevant Samanta et al data (which comes from their Supplement, Table S3) is this:

Note that the green area in the drought region increases to its maximum (10.8% of the total area = 10.8/33.68 = 32% of the valid area) in 2005. In other words, the Samanta et al data contradict the Samanta et al text and title (which states that Amazon forests did not green up): not only do forests in the drought region green up, they green up alot, more than any other year since the MODIS satellite sensor was launched.

Second, how does this compare to Saleska et al. (2007), which Samanta et al claim to rebut? Here are the numbers (again, taken directly from Samanta et al, Table S3 and Saleska et al., 2007):

Fraction of valid pixels in the 2005 drought region that are “green” (> + 1 Standard deviation)
Saleska et al. (2007): 34% (p<0.000001)
Samanta et al. (2010): 32% (p<0.004)

The bottom line is that their observed 2005 result (32% greenness) is indistinguishable from ours (34%). I.e. Samanta et al effectively reproduce the results of Saleska et al.

This summary response, of course, begs some very interesting questions about tropical forest function under climatic variability and change (indeed the most interesting questions of all!): what caused the anomalously disproportionate green-up in the drought region? And, even if satellite “green up” does in fact represent an increase in photosynthesis (as we think), could this in fact be a symptom of the trees compensating for the increased stress of the drought? The bottom line “carbon balance” of a tree depends on both photosynthetic uptake and respiratory losses, and it is almost certainly the case that those losses (which were not seen by the satellite) increased under the hotter and drier conditions of the drought as well.

Thus, the most intriguing idea to me is that the short-term satellite-detected green-up, and the longer term increase in net carbon loss reported in the Phillips et al paper (discussed by Simon Lewis) are not in conflict at all. It might well be that they represent different parts of a coherent forest response to drought, in which the longer term losses are larger than the satellite-detected attempt to compensate for them by increasing photosynthesis, and in the end, increased tree mortality is the result.

In conclusion I would like to reinforce Simon’s point about Samanta et al and the IPCC. More important than whatever they say about our one short paper, Samanta et al. truly and egregiously misrepresent the implications, of both their work and ours, when they claim that a single paper on short term vegetation response somehow rebuts the IPCC’s review of the large scientific literature on how Amazonia might respond to long-term shifts in the mean climate state. It is an illogical and misguided claim on many levels, one that is already and deservedly attracting the opprobrium of many of my colleagues, talented scientists who study Amazon forests and climate (see Scientists speak: Amazon “myths” are not debunked).

In sum:

– Samanta et al data show a drought region green up that is on average indistinguishable from Saleska et al (but they call it NO green up).
– Samanta et al data almost exactly reproduce Saleska et al’s most salient bottom-line result (but they say what we did was not reproducible).
– the Samanta et al paper, based on a three-month drought response, says not one word about long-term climate change scenarios reviewed in IPCC (but they advertise their analysis as “reject[ing] claims” put forward by the IPCC).

NASA’s Goddard Institute for Space Studies (GISS) has released a draft paper “Current GISS Global Surface Temperature Analysis.”  It is a must read for warming junkies, but, as James Hansen notes in an e-mail, “it is too long for popular use.”  So Hansen offers “some of the main conclusions,” as well as a description of a rather shocking hack of the GISS website (all of which is reprinted below).  The first conclusion is:

1) Contrary to popular belief, global warming has not stopped nor has the rate of warming even slowed down in the past decade (Figure 21).

The paper predicts a new record 12-month global temperature record, and says the calendar year (2010) is likely to set the global surface temperature unless “El Nino conditions deteriorate rapidly by mid 2010 into La Nina conditions” [as happened in 2007].  NASA notes:

This new record temperature will be particularly meaningful because it occurs when the recent minimum of solar irradiance (http://www.pmodwrc.ch/ pmod.php?topic=tsi/ composite/ SolarConstant) is having its maximum cooling effect.

Here are the rest of the summary conclusions of the paper, from Hansen’s email (I put in one relevant figure):

(2) 12-month running mean temperature is more revealing than the usual annual-mean graph, doing a better job of characterizing individual El Ninos, volcanoes, e.g., as well as providing an up-to-date assessment of annual mean temperature (Figures 9b and 10b).

(3) A new global temperature record (for the period of instrumental measurements) will be set within the next few months (Figure 10b and accompanying information).

(4) Urban effects on the analyzed global temperature are small (not a new conclusion) (Figure 3 and several more) – we account for it via satellite nightlight (Figure 1) identification of remote stations that are used to adjust the long-term trends of urban stations.

(5) Upside-down weather in the Northern Hemisphere this winter (Arctic warm, mid-latitudes cold) coincides with the most extreme Arctic Oscillation in the period 1950-2010.  The AO fluctuations from year to year are mostly weather noise, i.e., unpredictable chaotic fluctuations.  There seems no reason to anticipate frequent repeat performances – on the contrary, the slight long-term trend of the AO is toward more positive values and the (greenhouse gas driven) global warming trend has a larger effect than the AO trend on regional temperature, as well as on global temperature.  Of course winter weather will always be highly variable and those places cold enough to have snow can expect greater amounts from an atmosphere containing more water vapor.  The AO indices for the past three months are remarkable (Figure 15a), yet the cold temperature anomalies are relatively small compared to say the late 1970s (Figures 15b, 16, 17).

The paper will need a better summary/discussion section.  Not quite sure where I can send the final version.  The paper has relevance to current public discussions, but the usual scientific journals are not too accommodating for explicit discussion of that relevance.  Perhaps Atmospheric Chemistry and Physics is a possibility – which has a “Discussions” of papers pre-acceptance.  We used that journal for our paper “Dangerous human-made interference with climate: a GISS modelE study” – the referees there suggested that it was o.k. to include a brief section (Role of scientists in the climate debate), set off from the climate analysis, that included opinions about the public relevance.

Somehow we have to do a better job of communicating.  The tricks being used by people supporting denial and business-as-usual are recognizably dirty, yet effective.  We are continually burdened by sweeping FOIA (Freedom of Information Act) requests, which reduce our ability to do science and write it up (perhaps this is their main objective), a waste of tax-payer money.  Our analyses are freely available on the GISS web site as is the computer program used to carry out the analysis and the data sets that go into the program.

The material that we supplied to some recent FOIA requests was promptly posted on a website, and within minutes after that posting someone found that one of the e-mails included information about how to access Makiko Sato’s password-protected research directory on the GISS website (we had not noticed this due to the volume of material).  Within 90 minutes, and before anyone else who saw this password information thought it worth reporting to GISS staff, most if not all of the material in Makiko’s directory was purloined by someone using automated “web harvesting” software and re-posted elsewhere on the web. The primary material consisted of numerous drafts of webpage graphics and article figures made in recent years.

It seems that a primary objective of the FOIA requestors and the “harvesters” is discussions that they can snip and quote out of context.  On the long run, these distortions of the truth will not work and the public will realize that they have been bamboozled.  Unfortunately, the delay in public understanding of the situation, in combination with the way the climate system works (inertia, tipping points) could be very detrimental for our children and grandchildren. The public will need to put more pressure on policymakers, enough to overcome the pressure from special financial interests, if the actions needed to stabilize climate are to be achieved.

The paper itself is well worth reading, though not an easy slog.  Note that NASA says, “Criticism and comments are welcome and should be sent to” the email address here.

NASS GISS researchers deserve the strong support from all Americans who care about our children and grandchildren and future generations around the world.  They work tirelessly to provide the highest quality, peer-reviewed scientific research about the gravest preventable threat the human race faces — in the face of the most monstrous and effective disinformation campaign in human history.

In the United States, designated bike lanes and a growing bike culture have started to garner mainstream attention. And bicyclists now have a giant ally—Google, as explained in this CAP repost.

At the 10th Annual American Bike Summit in Washington, D.C. last week, Google announced their maps feature will include bike routes for 150 U.S. cities. The feature includes 15,000 miles of off-street bike trails gathered by the Rails-to-Trails Conservancy, a Washington, D.C.-based nonprofit that has collected trail info for its website since 2007.  [Image Source: Flickr/Hugger Industries.]

Google made the decision after receiving a petition with more than 50,000 signatures for bike routes to be added to its maps. Google Maps introduced driving directions in 2005, and in 2007 the site added transit routes. Pedestrian navigation followed a year later. Now, it’s the bikers’ turn.

Online tools for mapping bike routes have existed for years, such as RideTheCity.com, which also points out bike shops along your route. But with an organization as enormous as Google collating bike-friendly travel information, two-wheel enthusiasts hope city planners and politicians will take note and improve bicycling conditions across the United States, like Rep. Earl Blumenauer (D-OR) aims to do with his proposed Active Community Transportation Act. The bill seeks to make active transportation, such as walking or biking, more accessible and safe.

Promoting bicycle travel for utilitarian purposes, in addition to recreation and exercise, has become a federal objective since Congress opened new sources of funding for bicycle facilities with the Intermodal Surface Transportation Efficiency Act, or ISTEA, in 1991. This continued over the next decade and now federal planning requirements must consider bicyclists in state and Metropolitan Planning Organization, or MPO, long-range transportation plans.

The League of American Bicyclists, who sponsored the American Bike Summit, hopes the Google feature will encourage wary would-be cyclists to get on the road, give more seasoned bikers the respect they deserve, and curb unnecessary motorist pollution by highlighting safe routes:

• Dark green indicates a dedicated bike-only trail
• Light green indicates a dedicated bike lane along a road
• Dashed green indicates roads that are designated as preferred for bicycling but without dedicated lanes

The tool is far from perfect, however. It does not yet work for mobile devices, so bikers will have to map their routes from home or the office before setting out. And Google’s algorithm that combines input from bike lanes, topography, and traffic signals is still just an algorithm. Some New York Post writers reported being led the wrong way down one-way streets and onto off-limits sections of Central Park, and many routes in the District of Columbia are missing, such as the bike lane on 15th Street NW, the Metropolitan Branch Trail from Silver Spring to Union Station, and the Anacostia Riverwalk Trail.

Luckily, you can suggest a route change or make a correction using Google’s “report a problem” feature. Google is fielding these requests and working out the kinks in the system.

Traffic congestion and vehicle pollution is a massive problem, and many would-be bikers are put off by the lack of designated bike lanes in many U.S. cities. Hopefully, the added Google feature will get more people on bikes and force cities to designate more bike lanes. Cities with a higher level of bicycle infrastructure—paths and lanes—see higher levels of bicycle commuting, which then increases state and local spending on such infrastructure to keep those people on their bikes.

Additionally, bike infrastructure should connect to popular destinations—already marked on Google Maps—to increase pollution-free commuting. And more commuters should be educated about bicycling through individual bike ownership or shared programs such as SmartBike, which could be coupled with adequate and safe parking at work. All these steps could help give the United States a greater share of the world’s most bike-friendly cities.

In the United States, designated bike lanes and a growing bike culture have started to garner mainstream attention. And bicyclists now have a giant ally—Google, as explained in this CAP repost.

At the 10th Annual American Bike Summit in Washington, D.C. last week, Google announced their maps feature will include bike routes for 150 U.S. cities. The feature includes 15,000 miles of off-street bike trails gathered by the Rails-to-Trails Conservancy, a Washington, D.C.-based nonprofit that has collected trail info for its website since 2007.  [Image Source: Flickr/Hugger Industries.]

Google made the decision after receiving a petition with more than 50,000 signatures for bike routes to be added to its maps. Google Maps introduced driving directions in 2005, and in 2007 the site added transit routes. Pedestrian navigation followed a year later. Now, it’s the bikers’ turn.

Online tools for mapping bike routes have existed for years, such as RideTheCity.com, which also points out bike shops along your route. But with an organization as enormous as Google collating bike-friendly travel information, two-wheel enthusiasts hope city planners and politicians will take note and improve bicycling conditions across the United States, like Rep. Earl Blumenauer (D-OR) aims to do with his proposed Active Community Transportation Act. The bill seeks to make active transportation, such as walking or biking, more accessible and safe.

Promoting bicycle travel for utilitarian purposes, in addition to recreation and exercise, has become a federal objective since Congress opened new sources of funding for bicycle facilities with the Intermodal Surface Transportation Efficiency Act, or ISTEA, in 1991. This continued over the next decade and now federal planning requirements must consider bicyclists in state and Metropolitan Planning Organization, or MPO, long-range transportation plans.

The League of American Bicyclists, who sponsored the American Bike Summit, hopes the Google feature will encourage wary would-be cyclists to get on the road, give more seasoned bikers the respect they deserve, and curb unnecessary motorist pollution by highlighting safe routes:

• Dark green indicates a dedicated bike-only trail
• Light green indicates a dedicated bike lane along a road
• Dashed green indicates roads that are designated as preferred for bicycling but without dedicated lanes

The tool is far from perfect, however. It does not yet work for mobile devices, so bikers will have to map their routes from home or the office before setting out. And Google’s algorithm that combines input from bike lanes, topography, and traffic signals is still just an algorithm. Some New York Post writers reported being led the wrong way down one-way streets and onto off-limits sections of Central Park, and many routes in the District of Columbia are missing, such as the bike lane on 15th Street NW, the Metropolitan Branch Trail from Silver Spring to Union Station, and the Anacostia Riverwalk Trail.

Luckily, you can suggest a route change or make a correction using Google’s “report a problem” feature. Google is fielding these requests and working out the kinks in the system.

Traffic congestion and vehicle pollution is a massive problem, and many would-be bikers are put off by the lack of designated bike lanes in many U.S. cities. Hopefully, the added Google feature will get more people on bikes and force cities to designate more bike lanes. Cities with a higher level of bicycle infrastructure—paths and lanes—see higher levels of bicycle commuting, which then increases state and local spending on such infrastructure to keep those people on their bikes.

Additionally, bike infrastructure should connect to popular destinations—already marked on Google Maps—to increase pollution-free commuting. And more commuters should be educated about bicycling through individual bike ownership or shared programs such as SmartBike, which could be coupled with adequate and safe parking at work. All these steps could help give the United States a greater share of the world’s most bike-friendly cities.

And in anticipation of the latter, on British Airways (BA), Tandberg has wisely capitalized the opportunity to market its videoconferencing and telepresence solutions by offering TANDBERG FlyFree, a program that gives companies an easy and risk-free way of experiencing the power of high-definition video conferencing and telepresence.

By adopting Tandberg’s technology, it says employees “can still make critical meetings, avoid unnecessary business travel and benefit from a better work-life balance by working around personal schedules. In turn, the technology can deliver serious business advantages and consistent return on investment, regardless of the BA strikes, as well as help companies make great CO2, time and cost savings.”

“Businesses cannot afford to be slowed down by the impact of international travel disruption, especially at this time when continuity is so critical to success,” says Simon Egan, Vice President, Western Europe & Sub-Saharan Africa, Tandberg. “By accepting our FlyFree offer, businesses can still make important face-to-face meetings while maintaining productivity among employees. Our standards based solutions enable our customers to communicate with their partners, clients and suppliers so its business as usual even when working conditions are disrupted.”

Tandberg is onto something here. It should have similar offers with the green pitches launched in key seasons when North American air travel reliability goes into the toilet, like July-August and December-February and in specific markets like Atlanta, Chicago and New York/New Jersey. It should also buy billboard and monitor space in waiting lounges at LAX, Logan, Kennedy, O’Hare and in Canada, Pearson, to name a few, with images of relaxed business people in a meeting room or better yet on a home office desktop conference application with the catchline: ‘Wouldn’t You Rather Be Here?” The firm should also buy outside advertising on the Harbor Freeway, I-93, the Van Wyck, I-94 and the 401 respectively with the same message.

If more people went ‘fly free’ we could also breathe a little easier, and in more ways than one.
 

Tags: Tandberg, air travel, telepresence, video conferencing

Related Entries
• To Go Green, Make Videoconferencing Affordable – Oct 13, 2009
• Codian – Sep 07, 2007
• To Go Green (In More Ways than One) Go Virtual…and Bus and Rail – Dec 31, 2009
• Contributing Sources of Weird Weather? Look In The Mirror – Jul 31, 2009
• Goodbye, GM, Chrysler, Hello Green Alternatives – Nov 17, 2008
• Tandberg Data Offers Recycling Rebate Program – Apr 16, 2008
• Green Technology World Conference is Here! – Sep 07, 2007
• Green Technology Conference Doing Well – Sep 06, 2007
• TANDBERG – Aug 21, 2007

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A key part of the mission of Points of Light Institute is to encourage business leaders to create a company culture that inspires and enables employees to volunteer in the communities where they live and work. In the last decade, we have seen a dramatic increase in the commitment that companies are making to local communities. There is growing recognition that citizen engagement is essential to building strong communities, and business leaders understand that what is good for the community is good for their companies and employees.

The Principles of Excellence for Workplace Volunteering are to:

• Acknowledge that the workplace’s employee volunteer efforts contribute to the achievement of the company’s business goals;
• Commit to establish, support and promote an employee volunteer program that encourages the involvement of every employee and to treat it as any core business function;
• Target workplace volunteering towards serious social problems in the community.

Nominees are judged based on adherence to these principles, which are the benchmarks for the CEAE program. Last year’s winners included Capital One Financial Corporation, Deloitte LLP, Eli Lilly and Company, Pinnacol Assurance, and Salesforce.com.

Nominations must be submitted by April 9th, 2010. For more information on the award and the nomination form, please visit www.pointsoflight.org/recognition/corpaward, or contact Melanie Stevenson at mstevenson@pointsoflight.org, 404-574-5378.

The 2010 CEAE Award winners will be announced in early May. The awards will be presented to the honored companies during the annual National Conference on Volunteering and Service, the largest gathering of volunteer and service leaders from the non-profit, government and corporate sectors. That conference will take place in New York City in late June. Award recipients will also be showcased throughout the year by Points of Light Institute.

Points of Light Institute inspires, equips and mobilizes people to take action that changes the world. The Institute has a global focus to redefine volunteerism and civic engagement for the 21st century, putting people at the center of community problem-solving. We are organized to innovate, incubate and activate new ideas that help people act upon their power to make a difference. Points of Light Institute operates three dynamic business units that share our mission: HandsOn Network, MissionFish and the Civic Incubator.

Up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation; this means that the tropical vegetation, hydrology and climate system in South America could change very rapidly to another steady state, not necessarily producing gradual changes between the current and the future situation.

This statement in the 2007 IPCC is “basically correct but poorly written, and bizarrely referenced,” as tropical forest researcher Simon Lewis told the BBC in January.

That didn’t stop the anti-science blogosphere from spinning this into another phony “gate,” as ClimateSafety explained in an excellent post, “AmazonGate: how the denial lobby and a dishonest journalist created a fake scandal.”

Recently, the anti-science crowd, from FoxNews to Anthony Watts, has been crowing about a new study that supposedly shows the IPCC paragraph was wrong.  But a major statement by 19 top U.S., U.K., and Brazilian scientists who “conduct research on Amazon forests, climate, and/or fire,” thoroughly debunks that notion:

[Citations for original sources can be found here.]

Scientists’ statement on recent press release on Amazon susceptibility to reductions in rainfall: no Amazon rainforest “myths” have been debunked.

The press release from Boston University describing a recent article in the journal Geophysical Research Letters by BU researchers on the response of Amazon forests to the 2005 drought is misleading and inaccurate. It claims that the study “debunks myths about Amazon rainforests”, which is simply not true. First, there is no myth. Rather, there are multiple, consistent lines of evidence from ground-­‐based studies published in the peer-­‐reviewed literature that Amazon forests are, indeed, very susceptible to drought stress. Second, nothing is debunked by the new study. The new study contributes to our understanding of interpretations of data retrieved from satellites, but it does not prove or disprove anything about what is really happening on the ground. The BU press release also claims that the new BU paper demonstrates that the IPCC statement about the sensitivity of Amazon forests to small reductions in rainfall is inaccurate, which is also not true. While the IPCC statement could be criticized for citing a review paper rather than original research papers, the main conclusion of the IPCC statement – that Amazonian forests are very susceptible to reductions in rainfall – remains our best understanding of the data available at the time of the IPCC report and also today.

The article published by the BU group (in contrast to the BU press release) makes a scientific contribution to our knowledge of Amazon forests. It presents new analyses of the forest canopy conducted using satellite data from the MODIS sensor. The article challenges the findings of a previous analysis of forest response to the 2005 drought using similar data from the MODIS sensor. This earlier study, published in Science in 2007, concluded that southwestern Amazon forests fared well during the severe drought of 2005, reporting that these forests were greener in 2005, not browner as would be expected if the forests were stressed by drought. The new study found that the forests fared neither better nor worse, as indicated by the color of the canopy as seen from satellite images during the 2005 drought. Scientists are likely to continue to debate the differences in their analyses of the satellite imagery, and the articles in question illustrate the scientific learning process as we explore the potential and the limitations of satellite-­‐based measurements to give us information about forest response to drought in the Amazon region.

Forest tree measurements made under the forest canopy following the 2005 drought provide a very different picture of the sensitivity of Amazon rainforests to drought. In tree inventories conducted in 55 long‐term forest plots scattered across the Amazon forest, the drought of 2005 was associated with a large surge in tree mortality and no gains in growth. These findings, published in the journal Science in 2009, are consistent with the results of two large-­scale experiments, in which large canopy trees began to die after three years of experimentally reduced rainfall. The forest plot results are also consistent with studies of historical rainfall and soil water storage capacity and with simulation model analyses. These studies, published in some of the best peer-­reviewed science journals, provide several consistent lines of evidence that the forests of the Amazon Basin are susceptible to small reductions in rainfall. We do not know why the drought stress and tree mortality documented in the field studies published in the 2009 Science article and predicted based upon rainfall patterns were not detected in the analyses of satellite images by the Saleska-­ and Samanta-­led teams. It could be that tree deaths, which affect only a portion of the tree canopy, are hard to see in satellite images, especially if this tree death is accompanied by the growth of vines and plants on the forest floor. It could also be that the tree mortality induced by drought was sufficiently  delayed to be invisible in the imagery of 2005. This should be the topic of further research.

Reductions in rainfall can affect Amazon forests by increasing tree mortality, but also by increasing their susceptibility to fire. The initial fire kills trees, increasing the likelihood of subsequent fires for years afterwards in a vicious positive feedback loop. In 2005, more than 2000 km2 of forest caught fire in the tiny state of Acre alone. During the severe drought of 1998, approximately 40,000 km2 of forest caught fire. These are indisputable facts. It is important to remember that these droughts are part of the current Amazon climate regime. If climate change increases the frequency, severity or duration of these episodic droughts, then increased forest fire and tree mortality and reduced river flow are the likely results.

The IPCC must be held accountable for the best scientific information that is available in the peer-­review literature at the time of its writing. The passage in the IPCC that refers to the susceptibility of the Amazon forest to drought cites a World Wildlife Fund review report which, in turn, cites an article in the journal Nature. Ideally, the IPCC should have cited the Nature article as well as several other existing articles in support of its statement, and not a WWF report. The point is, however, that the statement made by the IPCC about the sensitivity of Amazon forests drought was consistent with our knowledge at that time, and has been reinforced by new studies.

You can find the signatories here.

You can read a shorter statement by Dr. Leeds on RealClimate.  There is an interesting back and forth between him and Dr. Samanta on RC (here) :

Folks,

The press release accompanying the GRL article disputed the following IPCC AR4 (2007) claim –

“Up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation; this means that the tropical vegetation, hydrology and climate system in South America could change very rapidly to another steady state, not necessarily producing gradual changes between the current and the future situation (Rowell and Moore, 2000). It is more probable that forests will be replaced by ecosystems that have more resistance to multiple stresses caused by temperature increase, droughts and fires, such as tropical savannas.”

for two reasons: (1) this is presented as the consensus view by quoting Rowell and Moore, 2000. (2) There was more than a slight reduction in precipitation during the third quarter of 2005 and, most of the drought-impacted forest area for which we have uncorrupted satellite greenness data showed no enhanced or reduced greenness levels (third quarter average EVI values) as compared to non-drought years (between 2000 and 2008).

It is only in this context that the material in the press release and the GRL must be understood. We do not dispute any other results related to this theme in these two documents.

Respectfully,
Arindam Samanta (on behalf of the authors of the GRL papers).

Dr. Leeds replied as follows:

Dear Arindam,Thanks for the response.

On the IPCC statement, as I have said it is not as well-worded as it ought to be. Strictly, perhaps it can be taken as having one of two different meanings,

1. That the IPCC mean that small reductions in precipitation at any given time cause a drastic response (of which your paper ably shows that for satellite-monitored ‘greenness’ there is no such drastic response, and is an important paper I will certainly cite), or

2. They mean responses of vegetation to mean climate regimes with differing precipitation (of which your paper says little).

It seems clear to me that the sentence is about responses to a shift from one climate regime, the recent past and present day, to another, with less precipitation, in the future (it is the IPCC climate change impacts report after all, and they do say ‘… not necessarily producing gradual changes between the current and the future situation’).

If meaning two of the sentence is taken, then what the IPCC say is reasonable, defensible, basic science: warm lower-rainfall environments tend to be dominated by savanna, while warm higher-rainfall environments tend to be dominated by rainforest, with a threshold amount of rainfall separating which vegetation type one finds. If substantial areas of the Amazon are in a climate regime close to the savanna-rainfall threshold, which diverse evidence suggests they are, then there may be a vegetation shift if rainfall consistently decreases in the future due to climate change.

Your response implies you think meaning one is correct, which is mistaken (logically it can’t hold as a proposition). Had your paper cited the IPCC chapter and the sentence you object to and why — which it doesn’t — the misunderstanding could have likely been addressed at the review stage.

Details aside, it’s the ‘debunking Amazon myths’ headlines, and quotes about putting right ‘muddled understanding’, and, “The way that the WWF report calculated this 40% was totally wrong, while [the new] calculations are by far more reliable and correct,” that are problematic and have unnecessarily confused people. There are no calculations in the WWF report (it’s a review), nor are there any new calculated updates on the IPCC ‘up to 40%’ statement in the Samanta paper, and the ‘muddled understanding’ quote highlights the ‘twin pressures’ facing the Amazon, as logging and climate change, when outright deforestation is certainly the number one current pressure in the context of the quote.

I know the media regularly run out of control (its happened to me several times), but in my view it is critical to try and put things right. Most journalists and bloggers will help put things right once they know there is a problem, but you have to tell them.

With best wishes,

Simon

Well, some journalists and bloggers will help put things right.  That’s why I’m posting all of this here.

Let me also quote from Dr. Leeds at RC:

Here is a recent paper that is consistent with the IPCC statement: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2374898/

This provides a way into lots of the literature. Also, see Lewis, S.L. (2006) Tropical forests and the changing earth system. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences, 361, 195-210. Available from this page: http://www.geog.leeds.ac.uk/ people/ slewis/ publications.html

The first paper Leeds sites is a “Towards quantifying uncertainty in predictions of Amazon ‘dieback’,” by Huntingford et al. which concludes:

Simulations with the Hadley Centre general circulation model (HadCM3), including carbon cycle model and forced by a ‘business-as-usual’ emissions scenario, predict a rapid loss of Amazonian rainforest from the middle of this century onwards….

We find that the loss of Amazonian rainforest is robust across the climate uncertainty explored by perturbed physics simulations covering a wide range of global climate sensitivity.

The “Amazon dieback” paper notes:

Besides acting as a positive feedback on climate, whereby additional carbon dioxide is released back into the atmosphere, the loss of the rainforest in itself would clearly be a significant environmental matter.

Precisely.

I’ll write about the meaning of that feedback in another post, but for now, let me repeat what I wrote in “Science stunner: Vast East Siberian Arctic Shelf methane stores destabilizing and venting“:

It is increasingly clear that if the world strays significantly above 450 ppm atmospheric concentrations of carbon dioxide for any length of time, we will find it unimaginably difficult to stop short of 800 to 1000 ppm.