AGW Observer

Observations of anthropogenic global warming

New research from last week 23/2011

Posted by Ari Jokimäki on June 13, 2011

Here is the new research published last week. I’m not including everything that was published but just some papers that got my attention. Those who follow my Facebook page (and/or Twitter) have already seen most of these, as I post these there as soon as they are published. Here, I’ll just put them out in one batch. Sometimes I might also point out to some other news as well, but the new research will be the focus here. Here’s the archive for the news of previous weeks. By the way, if this sort of thing interests you, be sure to check out A Few Things Illconsidered, they have a weekly posting containing lots of links to new research and other climate related news. Planet 3.0 also reports new research.

Published last week:

Excellent suggestions from Alan Betts

A Proposal for Communicating Science – Betts (2011) “I suggest authors must submit for review, and scientific societies be obliged to publish two versions of every journal. One would be the standard journal in scientific English for their scientific club. The second would be a parallel open-access summary translation into plain English of the relevance and significance of each paper for everyone else.” Alan Betts, Bulletin of the American Meteorological Society 2011, doi: 10.1175/BAMS-D-11-00036.1. [full text]

Research synthesis on Arctic sea ice

The Arctic’s rapidly shrinking sea ice cover: a research synthesis – Stroeve et al. (2011) “The sequence of extreme September sea ice extent minima over the past decade suggests acceleration in the response of the Arctic sea ice cover to external forcing, hastening the ongoing transition towards a seasonally open Arctic Ocean. This reflects several mutually supporting processes. Because of the extensive open water in recent Septembers, ice cover in the following spring is increasingly dominated by thin, first-year ice (ice formed during the previous autumn and winter) that is vulnerable to melting out in summer. Thinner ice in spring in turn fosters a stronger summer ice-albedo feedback through earlier formation of open water areas. A thin ice cover is also more vulnerable to strong summer retreat under anomalous atmospheric forcing. Finally, general warming of the Arctic has reduced the likelihood of cold years that could bring about temporary recovery of the ice cover. Events leading to the September ice extent minima of recent years exemplify these processes.” Julienne C. Stroeve, Mark C. Serreze, Marika M. Holland, Jennifer E. Kay, James Malanik and Andrew P. Barrett, Climatic Change, DOI: 10.1007/s10584-011-0101-1. [full text]

Many areas are entering permanent heat regime in next few decades

Observational and model evidence of global emergence of permanent, unprecedented heat in the 20th and 21st centuries – Diffenbauch & Scherer (2011) “Given the severe impacts of extreme heat on natural and human systems, we attempt to quantify the likelihood that rising greenhouse gas concentrations will result in a new, permanent heat regime in which the coolest warm-season of the 21st century is hotter than the hottest warm-season of the late 20th century. Our analyses of global climate model experiments and observational data reveal that many areas of the globe are likely to permanently move into such a climate space over the next four decades, should greenhouse gas concentrations continue to increase. In contrast to the common perception that high-latitude areas face the most accelerated response to global warming, our results demonstrate that in fact tropical areas exhibit the most immediate and robust emergence of unprecedented heat, with many tropical areas exhibiting a 50% likelihood of permanently moving into a novel seasonal heat regime in the next two decades. We also find that global climate models are able to capture the observed intensification of seasonal hot conditions, increasing confidence in the projection of imminent, permanent emergence of unprecedented heat.” Noah S. Diffenbaugh and Martin Scherer, Climatic Change, DOI: 10.1007/s10584-011-0112-y. [full text]

Warming climate is a threat to platybus

Early response of the platypus to climate warming – Klamt et al. (2011) “Combining a climatic envelope modeling technique with more than two centuries (1800-2009) of distribution records has revealed the effects of a changing climate on the egg-laying monotreme, the platypus, Ornithorhynchus anatinus. We show that the main factor associated with platypus occurrence switched from aquatic habitat availability (estimated by rainfall) to thermal tolerances (estimated by annual maximum temperature) in the 1960’s. This correlates directly with the change in the annual maximum temperature anomaly from cooler to warmer conditions in southeastern Australia. Modeling of platypus habitat under emission scenarios (A1B, A2, B1 and B2) revealed large decreases (> 30%) in thermally suitable habitat by 2070. This reduction, compounded by increasing demands for water for agriculture and potable use, suggests that there is real cause for concern over the future status of this species, and highlights the need for restoration of thermal refugia within the platypus’ modeled range.” Melissa Klamt, Ross Thompson, Jenny Davis, Global Change Biology, DOI: 10.1111/j.1365-2486.2011.02472.x.

Rapid melt has started in Canada’s Arctic ice caps

Extreme melt on Canada’s Arctic ice caps in the 21st century – Sharp et al. (2011) “Canada’s Queen Elizabeth Islands contain ∼14% of Earth’s glacier and ice cap area. Snow accumulation on these glaciers is low and varies little from year to year. Changes in their surface mass balance are driven largely by changes in summer air temperatures, surface melting and runoff. Relative to 2000–2004, strong summer warming since 2005 (1.1 to 1.6°C at 700 hPa) has increased summer mean ice surface temperatures and melt season length on the major ice caps in this region by 0.8 to 2.2°C and 4.7 to 11.9 d respectively. 30–48% of the total mass lost from 4 monitored glaciers since 1963 has occurred since 2005. The mean rate of mass loss from these 4 glaciers between 2005 and 2009 (−493 kg m−2 a−1) was nearly 5 times greater than the 1963–2004 average. In 2007 and 2008, it was 7 times greater (−698 kg m−2 a−1). These changes are associated with a summer atmospheric circulation configuration that favors strong heat advection into the Queen Elizabeth Islands from the northwest Atlantic, where sea surface temperatures have been anomalously high.” Sharp, M., D. O. Burgess, J. G. Cogley, M. Ecclestone, C. Labine, and G. J. Wolken (2011), Geophys. Res. Lett., 38, L11501, doi:10.1029/2011GL047381.

Clear warming in Arabian Peninsula

Recent observed climate change over the Arabian Peninsula – AlSarmi & Washington (2011) “We have examined trends in temperature and precipitation parameters for the Arabian Peninsula (AP) during the last 2 to 3 decades. The data set has been carefully quality controlled and checked for homogeneity. Although of low density (21 stations) and relatively short time period, a clear picture of climate change in the region has emerged. The general pattern of the AP mean annual temperature trend is one of warming, with 14 of 21 stations show statistically significant warming at 0.05 level and most at 0.001 level and only one (Seeb) showing statistically significant cooling. The highest statistically significant mean annual warming trends are found in Oman (Sur = 1.03°C decade−1) and Emirates (Dubai = 0.81°C decade−1). The season of maximum warming in mean temperature is March to April. The highest monthly mean temperature trend in the AP occurs in Sur in May (1.47°C decade−1). There is a broad statistically significant increase in mean annual maximum temperature in AP in 12 out of 21 stations, with the highest trends in central and eastern/southeastern AP. Only SW AP and the Gulf of Oman do not show warming. The highest monthly maximum temperature trend in the AP occurs in Bahrain in March (2.27°C decade−1). The second highest significant warming trends are reported in Doha in February (1.54°C decade−1). For minimum temperature, 16 out of 21 stations show statistically significant warming trends, with the highest annual trends observed in the Emirates (Dubai = 1.24°C decade−1), northwest Oman (Sohar = 1.17°C decade−1) and Qatar (Doha = 1.13°C decade−1). The highest monthly minimum temperature warming rate occurred in October. Both Dubai and Kuwait reported the highest significant rate of 2.00°C decade−1. The general mean annual diurnal temperature range trend is negative in the AP, with six out of 21 stations show statistically significant negative trends while three stations show statistically significant positive trends. Trends in mean annual precipitation are significant at only two stations which show a decrease in precipitation.” AlSarmi, S., and R. Washington (2011), J. Geophys. Res., 116, D11109, doi:10.1029/2010JD015459.

Climate change increases dust over Mongolia

Recent increasing trend in dust frequency over Mongolia and Inner Mongolia regions and its association with climate and surface condition change – Lee & Sohn (2011) “Trends in dust events over China and Mongolia were examined using 34 years (1974–2007) of visibility data over dust source regions of China and 10 years (1998–2007) of dust reports from Synoptic Observations (SYNOP) stations over China and Mongolia. Dust occurrences in Mongolia and northern Inner Mongolia increased over the 1998–2007 SYNOP data period while most dust source regions of China experienced a continuous decrease over the 34-year data period. Increased dust occurrences in Mongolia as well as in Inner Mongolia appear to be caused by degraded surface vegetation and reduced soil moisture associated with intensified drought conditions after the mid-1990s. Results suggest that recent increases in dust events over Korea and Japan are linked to increased dust occurrences over Mongolia and Inner Mongolia.” Eun-Hee Lee and Byung-Ju Sohn, Atmospheric Environment, doi:10.1016/j.atmosenv.2011.05.065.

In Buenos Aires population grows but UHI decreases

Temporal variability of the Buenos Aires, Argentina, urban heat island – Camilloni & Barrucand (2011) “This paper describes the statistical characteristics and temporal variability of the urban heat island (UHI) intensity in Buenos Aires using 32-year surface meteorological data with 1-h time intervals. Seasonal analyses show that the UHI intensity is strongest during summer months and an “inverse” effect is found frequently during the afternoon hours of the same season. During winter, the UHI effect is in the minimal. The interannual trend and the seasonal variation of the UHI for the main synoptic hours for a longer record of 48 years are studied and associated to changes in meteorological factors as low-level circulation and cloud amount. Despite the population growth, it was found a negative trend in the nocturnal UHI intensity that could be explained by a decline of near clear-sky conditions, a negative trend in the calm frequencies and an increase in wind speed. Urban to rural temperature differences and rural temperatures are negatively correlated for diurnal and nocturnal hours both for annual and seasonal scales. This result is due to the lower interannual variability of urban temperatures in comparison to rural ones.” Inés Camilloni and Mariana Barrucand, Theoretical and Applied Climatology, DOI: 10.1007/s00704-011-0459-z.

Pacific winds have intensified possibly due to global warming

Evidence for strengthening of the tropical Pacific Ocean surface wind speed during 1979–2001 – Li & Ren (2011) “Using multiple surface wind speed (SWS) data sets and trend empirical orthogonal function analysis, we have explored the trend in SWS associated with the large-scale tropical Pacific atmospheric circulation for the period 1979–2001. The present research provides a robust evidence of strengthening of the tropical Pacific Ocean SWS during this period and the magnitude is generally in line with the finding of Wentz et al. The strengthening in SWS is closely associated with the so-called La Niña-like sea surface temperature (SST) trend pattern rather than the changes in the ENSO, ENSO Modoki, or PDO. The present results, together with those from some recent climate model simulations, suggest that global warming forcing may have caused an intensification of SWS in the tropical Pacific Ocean by inducing the La Niña-like SST trend pattern due to ocean dynamics. Meanwhile, the strengthening in the tropical Pacific Ocean surface trade winds may also feedback to enhance the La Niña-like SST trend pattern under the positive wind-upwelling dynamic feedback mechanism.” Gen Li and Baohua Ren, Theoretical and Applied Climatology, DOI: 10.1007/s00704-011-0463-3.

PETM carbon emissions were much slower than today

Slow release of fossil carbon during the Palaeocene–Eocene Thermal Maximum – Cui et al. (2011) “The transient global warming event known as the Palaeocene–Eocene Thermal Maximum occurred about 55.9 Myr ago. The warming was accompanied by a rapid shift in the isotopic signature of sedimentary carbonates, suggesting that the event was triggered by a massive release of carbon to the ocean–atmosphere system. However, the source, rate of emission and total amount of carbon involved remain poorly constrained. Here we use an expanded marine sedimentary section from Spitsbergen to reconstruct the carbon isotope excursion as recorded in marine organic matter. We find that the total magnitude of the carbon isotope excursion in the ocean–atmosphere system was about 4‰. We then force an Earth system model of intermediate complexity to conform to our isotope record, allowing us to generate a continuous estimate of the rate of carbon emissions to the atmosphere. Our simulations show that the peak rate of carbon addition was probably in the range of 0.3–1.7 Pg C yr−1, much slower than the present rate of carbon emissions.” Ying Cui, Lee R. Kump, Andy J. Ridgwell, Adam J. Charles, Christopher K. Junium, Aaron F. Diefendorf, Katherine H. Freeman, Nathan M. Urban & Ian C. Harding, Nature Geoscience, 2011, doi:10.1038/ngeo1179.

Thawing permafrost makes wetlands smaller

Reduction in areal extent of high-latitude wetlands in response to permafrost thaw – Avis et al. (2011) “Wetlands are vegetated regions that are inundated with water on a permanent, seasonal or intermittent basis. These ecosystems play an important role in the carbon cycle: wetlands take up and store carbon, and release carbon dioxide and methane through the decomposition of organic matter. More than 50% of wetlands are located in the high northern latitudes, where permafrost also prevails and exerts a strong control on wetland hydrology. Permafrost degradation is linked to changes in Arctic lakes: between 1973 and 2004 the abundance of lakes increased in continuous permafrost zones, but decreased in other zones. Here, we use a global climate model to examine the influence of permafrost thaw on the prevalence of high-latitude northern wetlands, under four emissions scenarios. We show that as permafrost degrades, the areal extent of wetlands declines; we found a net loss in wetland extent in the three highest emissions scenarios. We also note an initial increase in the number of days of the year conducive to wetland formation, owing to an increase in unfrozen surface moisture resulting from a lengthening of the thaw season. This is followed by a dramatic decline in the number of wetland-conducive days, owing to a deepening of the permafrost surface, and drainage of near-surface moisture to deeper soil layers. We suggest that a reduction in the areal extent and duration of wetlands will influence high-latitude carbon emissions.” Christopher A. Avis, Andrew J. Weaver & Katrin J. Meissner, Nature Geoscience, 2011, doi:10.1038/ngeo1160.


7 Responses to “New research from last week 23/2011”

  1. Kevin C said

    The Betts item on communication is very interesting. On the whole I agree, indeed when submitting grants in the UK we already have to do exactly this.

    However, I think the problem may be a little more subtle than reading Betts might suggest. The issue is that science requires a way of thinking which is slightly alien to the way in which people normally think. As scientists we often don’t even realise this, and yet without doing so we have no hope of communicating effectively to a non-technical audience.

    This alienness is subtle, but it manifests itself even in the way we use language. Here is a systematic grammar paper on the issue:
    The issue of grammatical metaphor being the most intersting. In everyday language I might say ‘The sun was shining so I hung out the laundry’, but not ‘The shining of the sun caused the hanging out of the laundry’. In everyday language the first form is common, in scientific language the second is common, and they relate to the different ways of thinking about the world – crudely intentions and motivations versus causes and effects.

    So training would be required, at the very least. But how many of us can think of one issue in both frames? Not sure.

  2. Ari Jokimäki said

    Even if there would be problems, I think Betts’ suggestion still gives better result than having a journalist write a piece on a new study. Also, I think in the long run this would teach people to think more scientifically, at least a bit anyway.

    Another upside is that there would be more studies available to regular citizens. Currently situation is such that certain media select few articles to report. Those are usually from Science, Nature, or PNAS and rarely something from journals of less impact. If we would do it Betts’ way, all studies would be reported so this might also broaden the knowledge people have on science. Currently there’s not much chance that your average citizen would get to know some method development paper but in this new system some of them might even read about that. In the process they might learn how science works on larger scale.

  3. CP said

    In this sense, the media should also release transcripts of interviews. ps. the link to Betts post is not working.

  4. Ari Jokimäki said

    I just tried both the abstract link and the full text link and they are working for me. Perhaps just a short break in AMS or something.

  5. CP said

    The related twitter link does not work.

  6. Ari Jokimäki said

    I see, thanks. It seems that Twitter’s link shortener doesn’t like that link. I tried it again and it still wouldn’t work, so I used bitly link instead. Apparently Twitter doesn’t seem to have an option for switching the link shortening off, it just decides to shorten your link.

  7. CP said

    I don’t know how ledgit this is but i like this because cc is also the short for climate change 🙂

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