More on land use change affecting temperatures

Pursuant to the story on sugarcane cooling the local climate, here are two posts from Dr. Roger Pielke Senior that show the effects of land use change in other venues.

From: Dev Nyogi - The Impacts of LCLUC Change: Energy Balance and Climate - see below

==============================================================

Excellent Presentation Of Land Use/Land Cover Effects On Climate By Dev Niyogi Of Purdue

There is an excellent powerpoint presentation by Dev Niyogi of Purdue University at the 15th Annual LCLUC Science Team Meeting, March 28-30th 2011 at the University of Maryland. It is

The Impacts of LCLUC Change: Energy Balance and Climate

The question he poses is

“Is there a detectable relation between LULCC as a driver for weather and climate change – and what is needed to understand this further?

The entire set of viewgraphs is a valuable addition to our understanding of the role of land cover/land use change [LCLUC] within the climate system. Dev’s insightful conclusions from his talk are:

  • LULCC has a profound impact on the regional‐scale surface energy and water balance and where it has been intensive.
  • Growing detectable evidence about weather and climatic feedbacks and possible teleconnections associated with LULCC.
  • The LULCC impact is likely on a par with other major global forcings but unlike warming seen from GHG emissions , LULCC forcing is multi directional and can warm/ cool, cause positive/negative feedbacks depending on the region and timing.
  • The fact that the impact of LULCC is small with respect to the global average radiative forcing, with the exception of emissions of CO2, is, however, not a relevant metric as the essential resources of food, water, energy, human health and ecosystem function respond to regional and local climate not to a global average.

Without a complete assessment of the role of LULCC on climate, an incomplete understanding of the of humans in the climate system will persist.”

=========================================================

New Paper “Land-Cover and Surface Water Change Drive Large Albedo Increases in South America” By Loarie Et Al 2011

There is a new paper that illustrates an important climate forcing.
Loarie, Scott R., David B. Lobell, Gregory P. Asner, Christopher B. Field, 2011: Land-Cover and Surface Water Change Drive Large Albedo Increases in South America. Earth Interact., 15, 1–16.doi: 10.1175/2010EI342.1

The abstract reads [boldface added]

Albedo is an important factor affecting global climate, but uncertainty in the sources and magnitudes of albedo change has led to simplistic treatments of albedo in climate models. Here, the authors examine nine years (2000–08) of historical 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) albedo estimates across South America to advance understanding of the magnitude and sources of large-scale albedo changes. The authors use the magnitude of albedo change from the arc of deforestation along the southeastern edge of the Brazilian Amazon (+2.8%) as a benchmark for comparison. Large albedo increases (>+2.8%) were 2.2 times more prevalent than similar decreases throughout South America. Changes in surface water drove most large albedo changes that were not caused by vegetative cover change. Decreased surface water in the Santa Fe and Buenos Aires regions of Argentina was responsible for albedo increases exceeding that of the arc of deforestation in magnitude and extent. Although variations in the natural flooding regimes were likely the dominant mechanism driving changes in surface water, it is possible that human manipulations through dams and other agriculture infrastructure contributed. This study demonstrates the substantial role that land-cover and surface water change can play in continental-scale albedo trends and suggests ways to better incorporate these processes into global climate models.”

This study supports our findings of a significant human effect on weather and climate through land use change in South America in our paper

Beltran-Przekurat, A., R.A. Pielke Sr., J.L. Eastman, and M.B. Coughenour, 2011: Modeling the effects of land-use/land-cover changes on the near-surface atmosphere in southern South America. Int. J. Climatol., accepted.

The abstract reads

GEMRAMS, a coupled atmospheric-biospheric model comprised of the Regional Atmospheric Modeling System and the General Energy and Mass Transport Model, was used to evaluate potential effects of land-use/land-cover changes (LULCC) on near-surface atmosphere over a southern South American domain. Several spring-early summer simulations were conducted using different land-cover scenarios representing current, natural, and afforestation conditions for this region for three periods, associated with El Niño- Southern Oscillation (ENSO) conditions. Changes in surface fluxes and the associated effects on near-surface temperature were spatially heterogeneous: different vegetation changes led to different effects. These changes were also associated with the seasonality of the vegetation. Conversion from grass to agriculture led to cooler, wetter near-surface atmospheric conditions. Warmer temperatures resulted from the conversion ofwooded grasslands or forest to agriculture. Afforestation resulted overall in cooler temperatures. For both LULCC scenarios the direction of the energy fluxes and temperature changes remained in general the same in two extreme ENSO years, although for some vegetation conversions the signal reversed direction. Overall, the impacts were enhanced during a dry year, i.e., 1999-2000, but the response also depended on the vegetation types involved in the conversion. The effects on precipitation were insignificant in the agriculture-conversion scenario. In simulated austral summer precipitation, the afforested scenario generated average increases of 1 mm day−1. The impacts were relatively higher for a “dry year”.

The Loarie et al 2011 study also provides support for the importance of dams and their effect on  evaporation and transpiration from adjacent landscapes on local and regional climate that we reported on in

Hossain, F., I. Jeyachandran, and R.A. Pielke Sr., 2010: Dam safety effects due to human alteration of extreme precipitation. Water Resources Research, 46, W03301, doi:10.1029/2009WR007704.

Degu, A. M., F. Hossain, D. Niyogi, R. Pielke Sr., J. M. Shepherd, N. Voisin, and T. Chronis, 2011: The influence of large dams on surrounding climate and precipitation patterns. Geophys. Res. Lett., 38, L04405, doi:10.1029/2010GL046482.

The Loarie et al paper is also interesting as one of the authors, Chris Field, is a Co-Chair of Working Group II of the current IPCC assessment.  In this position, he should be introducing the need for a broader perspective on the role of humans within the climate system. Unfortunately, however, this perspective needs to be also in Working Group I’s report since that is the foundation for the other IPCC reports.

About these ads

14 thoughts on “More on land use change affecting temperatures

  1. Saying that petroleum is using locked up carbon..
    …while saying that plants like sugar cane are just recycling carbon

    Might give everyone a warm glowy….

    Plants are taking carbon out of the soil, and putting it in the air….
    Soils contain 75% of the terrestrial inventory of carbon.
    Respiration from sugarcane releases ~25% more carbon than native forest and soil temperatures are significantly higher

    simple enough

    http://www.fs.fed.us/rm/rwu4352/staff/papers/Rhoades/10%20Rhoades%20et%20al%2000%20Ecol%20Appl%20.pdf

  2. Land use change: Forest Service stymied by injunctions from salvage operations after intense fires leads to trees replanted in areas with enough fuel to reburn the affected areas. The decreased precipitation due to lessened resistance to moisture-bearing clouds ensures further destruction by the remaining fuels not cleared out.
    And they continue to blame Global Warming, naturally.

  3. “Unfortunately, however, this perspective needs to be also in Working Group I’s report”

    Nah, it just needs to be in the summary for policymakers.

    P.S. Thanks for the extra excerpts from the cited materials. :)

  4. Latitude says:
    April 18, 2011 at 11:49 am

    Plants are taking carbon out of the soil, and putting it in the air….
    Soils contain 75% of the terrestrial inventory of carbon.
    Respiration from sugarcane releases ~25% more carbon than native forest and soil temperatures are significantly higher

    When I was in 1st year biology my teacher asked the question if the plant gets its mass from the soil why does the soil level rise rather than plant roots becoming exposed as the plant grows? The only explanation us children could think of was that most of plant mass comes from the air. Is there another explanation for peat 2o+ feet deep in Scotland and Ireland? Noting also that at the bottom of that peat there is a layer of tree stumps and then very poor quality soil.

    Just confused now.

  5. Of course land use changes the local climate (as a synonym for environment), seldom, apparently, the local weather in its totality though.

    But since when did major changes become good for the environment and “global climate”?

    If someone is making loads of money on something, that is otherwise portrayed as being negative, and there’s a something saying it is for the best of the whole wide world of this planet, people probably do best with being sceptic towards such biased claims. (Follow the links and money in the sugar cane BS for instance.)

    First they wanted to save the forest to save the world, now they want to chop down the forest to save the world, in both instances they never produced any empirical observed evidence, only spatial belief.

    At least the hippie bird lover is one one can respect, but the generalized save-the-planet-climate friggin hippie one cannot respect for they care for not one but their own ego.

  6. unlike warming seen from GHG emissions , LULCC forcing is multi directional and can warm/ cool, cause positive/negative feedbacks …

    Personally, I not at all certain about the truth of this statement. I suspect we are just beginning to understand all the interactions that affect climate.

  7. Latitude says:
    Plants are taking carbon out of the soil, and putting it in the air….

    And here I thought plants took carbon from CO2 in the air and released O2 into the air.

  8. It looks as if it’s all about the greenhouse gas H2O. Already the Romans know this. They always left a bit of forest on top of the hills. Kilimanjaro is a good example. No forest no H2O.

  9. What a pecular muted response to this thread subject. Pielke Snr has been a long-term skeptic of the standard AGW theory and it might be supposed would have been a popular essayist on this site – yet instead it gets (so far) only 7 posts, and not much on topic.

    My own response to Pielke’s work on land use change is that while it is qualitatively persuasive, there seems to be very little QUANTITATIVE content that would allow comparisons of the impact of hydrological changes in relation to albedo changes relative to GHG changes etc. It lacks numerical rigour.

    But I am intruged by the very thin response from the usual posters here, is it because it confirms their preference in one way – by calling into question the dominance of CO2 in any climate change; but then contradicts the local ‘concensus’ of no danger from climate change by acknowledging that land use change and human agriculture CAN have profound impacts on the environment.
    The cognative dissonance between the two opposing concepts is apparently just too much for many here!

  10. Izen misunderstands Festinger’s theory of cognitive dissonance, and so misstates the skeptical position. To the best of my knowledge there is no argument claiming that changes in land use cannot have any effect on regional climates. Therefore, there are not “two oposing concepts.”

    In general, skeptics correctly point out that the claim that CO2 is the primary driver of temperatures has never been validated, and further, that the planet is contradicting the claim by cooling as CO2 rises. CAGW is a failed conjecture with no measurable, testable evidence to support it. So it follows that making far reaching, extremely costly economic policies based on the demonization of “carbon” is extremely injurious to the taxpaying public, while being financially self-serving for its sceming proponents.

  11. @-Smokey says:
    April 19, 2011 at 7:18 am
    “Izen misunderstands Festinger’s theory of cognitive dissonance, and so misstates the skeptical position. To the best of my knowledge there is no argument claiming that changes in land use cannot have any effect on regional climates. Therefore, there are not “two oposing concepts.”

    Actually I prefer Bem’s formulation, and the Pielke argument is not that land use changes just have effects on regional climates but have an influence on global climate. It is that which I suspect contradicts the underlying assumption of many here that human action cannot have ANY global effect on climate.

    -“In general, skeptics correctly point out that the claim that CO2 is the primary driver of temperatures has never been validated, and further, that the planet is contradicting the claim by cooling as CO2 rises. “-

    Wrong on two counts, no scientist would argue that CO” is the PRIMARY driver of temperature, it is one of many, but very much secondary to the Sun and H2O. Second, if you really think that the globe is cooling…

  12. Supercomputer Climate Models need to factor in historical LCLU data. The argument that man is destroying the World needs to show how and where and when and who and a little more what. Let’s go back, to say the timeframe of 1 Billion people on the planet. Let’s show that from then to the present, with this environmental impact and that impact, etc., etc., this and that has been happening. Now, let’s show that by reforestation, or bringing back the great grasslands of the American Midwest, and/or destroying a city or fifty here and there, or blowing up Hoover Dam and that thing the Chinese have been building, etc., we can save the World. Now that would be interesting. Hope it doesn’t cost too much federal grant money. We are a little broke and studies can be expensive. Maybe we could talk the Chinese into funding and managing the study. (SarcOff)

  13. I’ll have to disagree with Izen’s opinion of Bem, who was only riding Festinger’s coattails, and Bem was at least partially falsified to boot. Actually, I prefer Orwell’s doublethink over Festinger, which really cuts to the chase: as Winston Smith wondered, if everybody believes that 2 + 2 = 5, would that make it true?

    So if the supporters of the consensus believe that CO2 will cause runaway global warming, does that make it true? That’s the Tinkerbell theory of science: with a strong enough belief, that will make it true [it helps to clap your hands]. But that pesky scientific method always gets in the way of beliefs.

    Next, if Izen was not winging it, I would like for him to please name the commentators who state that human activity cannot have any effect on the climate. As Willis says, quote the words. For myself, I have never read a post saying that humans can not have any effect. Maybe I just missed those particular comments.

    Finally, Izen says, “Wrong on two counts, no scientist would argue that CO is the PRIMARY driver of temperature, it is one of many, but very much secondary to the Sun and H2O. Second, if you really think that the globe is cooling…”

    Actually, right on both counts, I think. For example:

    First, Michael Mann is a scientist. Not a very good one it’s true, but his Hokey Stick chart, in which he correlated the rise in CO2 with the subsequent rise in temperature, argues that human-emitted CO2 is the culprit. And of course there are those inconvenient Climategate emails, and Harry the programmer, who wrote that he was fabricating years of temp data that showed a ramp-up in warming. And IPCC scientists, many of whom lay the blame for the past century’s [mostly or entirely natural] warming on human emitted CO2. All it takes to falsify a statement is one example; I’ve provided several here.

    Second, Izen doesn’t specify any parameters to argue that the globe hasn’t started cooling, so I’ll throw this out. It’s far from proof. But it’s certainly going in the direction of cooling, no?

  14. @-Smokey says:
    April 19, 2011 at 1:05 pm
    “I’ll have to disagree with Izen’s opinion of Bem, who was only riding Festinger’s coattails, and Bem was at least partially falsified to boot. Actually, I prefer Orwell’s doublethink over Festinger, which really cuts to the chase:”

    I would agree that Orwell’s insight into cog-dis is better than the acedemics, the concept of ‘Morton’s Demon’ is also rather good at explicating the way people deasl with conceptual conflicts.

    “Next, if Izen was not winging it, I would like for him to please name the commentators who state that human activity cannot have any effect on the climate.”

    Well I think you will have FAR more problems finding scientists who support the idea that runaway global warming is likely than I will have problems finding posters here who reject ANY influence from CO2. In fact recently there was a thread –

    http://wattsupwiththat.com/2011/02/07/global-warming-is-a-pussy-cat/

    Where people openly declared their assesment of the role of CO2.
    Richard Vernay, Lucy Skywalker, Edmh, Ed Caryl, James Barker, Scarface and of course the thread author Ira Glickstein all declared that the role of human produced CO2 in any warming was negligible or zero.

    Its the lack of those same posters declaring with equaly certainty that land-use changes are negligible in the face of Pielke Snr’s assesments that I find interesting….

    -“First, Michael Mann is a scientist. Not a very good one it’s true, but his Hokey Stick chart, in which he correlated the rise in CO2 with the subsequent rise in temperature, argues that human-emitted CO2 is the culprit.”-

    But not that CO2 is a PRIMARY driver of temperature. No scientist I know of advocates that the MWP or the LIA were the result of CO2 changes. Solar variation and volcanic influences are much more often invoked. The ice-age cycles are ascribed to orbital variations, not CO2 and the only other time climate change has been attributed to a rise in CO2 as the primary cause would be the PETM.

    There seems to be a tendency for simplistic binary dichotomies in people’s thinking on this issue. Either CO2 is the cause of all warming, or none, the reality that its probably the direct cause of around half the last century’s climate change seems peculiarly resistant to acceptance. Perhaps it is the fault of the human preference for simple narratives rather than engaging with the full complexity of the material world.

    “Second, Izen doesn’t specify any parameters to argue that the globe hasn’t started cooling, so I’ll throw this out. It’s far from proof. But it’s certainly going in the direction of cooling, no?”

    And this week it is colder than last (I’m in the N hemisphere) so the seasonalists claim that the small increases in solar input will cause a hemispheric warming they call ‘summer’ is a theory in crisis.

Comments are closed.