New Research

[knocker]

Biological processes on glacier and ice sheet surfaces

Glaciers and ice sheets are melting in response to climate warming. Whereas the physical behaviour of glaciers has been studied intensively, the biological processes associated with glaciers and ice sheets have received less attention. Nevertheless, field observations and laboratory experiments suggest that biological processes that occur on the surface of glaciers and ice sheets — collectively termed supraglacial environments — can affect the physical behaviour of glaciers by changing surface reflectivity. Furthermore, supraglacial cyanobacteria and algae capture carbon dioxide from the atmosphere and convert it into organic matter. Supraglacial microbes break down this material, together with organic matter transported from further afield, and generate carbon dioxide that is released back into the atmosphere. The balance between these two processes will determine whether a glacier is a net sink or source of carbon dioxide. In general, ice sheet interiors seem to function as sinks, whereas ice sheet edges and small glaciers act as a source. Meltwaters flush microbially modified organic matter and pollutants out of the glacier, with potential consequences for downstream ecosystems. We conclude that microbes living on glaciers and ice sheets are an integral part of both the glacial environment and the Earth's ecosystem.

 

 

http://www.nature.com/ngeo/journal/v5/n11/full/ngeo1611.html

[knocker]

Climate change will cause widespread global-scale loss of common plants and animals

 

More than half of common plants and one third of the animals could see a dramatic decline this century due to climate change – according to research from the University of East Anglia.

 

Research published today in the journal Nature Climate Change looked at 50,000 globally widespread and common species and found that more than one half of the plants and one third of the animals will lose more than half of their climatic range by 2080 if nothing is done to reduce the amount of global warming and slow it down.

This means that geographic ranges of common plants and animals will shrink globally and biodiversity will decline almost everywhere.

 

http://www.uea.ac.uk/mac/comm/media/press/2013/May/climate-change-warren-common-species

Edited May 12, 2013 by knocker

[4wd]

400ppm CO2 also confirmed at the AEMET Izana observatory on Tenerife http://izana.aemet.es/index.php?option=com_content&view=article&id=320%3Athe-co2-has-surpassed-the-threshold-of-400-ppm&catid=10%3Anews&Itemid=49〈=en

http://www.latimes.com/news/science/sciencenow/la-sci-sn-carbon-dioxide-400-20130513,0,7196126.story

Or not. Nevermind, the hype can come around again next year, double whammy.

[Methuselah]

Can't see any 'hype', 4...It either has or it has not breached 400 ppm...

[knocker]

Scientists find extensive glacial retreat in Mount Everest region

Cancún, Mexico—Researchers taking a new look at the snow and ice covering Mount Everest and the national park that surrounds it are finding abundant evidence that the world’s tallest peak is shedding its frozen cloak. The scientists have also been studying temperature and precipitation trends in the area and found that the Everest region has been warming while snowfall has been declining since the early 1990s.

 

 

http://www.agu.org/news/press/pr_archives/2013/2013-20.shtml

[knocker]

Sulfate aerosols cool climate less than assumed

 

Life span of cloud-forming sulfate particles in the air is shorter than assumed due to a sulfur dioxide oxidation pathway which has been neglected in climate models so far

 

Sulfur dioxide is as antagonist of greenhouse gases less effective than previously assumed. It forms sulfate aerosol particles in the air, which reflect sunlight, and as so-called cloud condensation nuclei influence the chemical processes within clouds. Therefore, sulfate aerosol particles help to cool the earth, making them an important factor in climate models. However, a team around researchers from the Max Planck Institute for Chemistry found out that it is likely most models overestimate the cooling effect of these particles. The reason is a largely disregarded reaction pathway catalysed by mineral dust within clouds, which has a strong influence on the life span of sulfate aerosol particles and their ability to reflect sunlight.

 

 

http://www.mpg.de/7248507/sulfate-aerosol-clouds-climate

Edited May 14, 2013 by knocker

[knocker]

Dependence of hydropower energy generation on forests in the Amazon Basin at local and regional scales

Abstract

Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations’ energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local “direct†effects (through changes in ET within the watershed) and the potential regional “indirect†effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world’s largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4–8% and 10–12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6–36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry’s own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests.

 

 

http://www.pnas.org/content/early/2013/05/09/1215331110

[knocker]

New UN study highlights huge potential for generating clean energy in Africa

13 May 2013 – Less than 1 per cent of all patent applications relating to clean energy technology (CET) have been filed in Africa, according to a new United Nations study, which also highlights the opportunity for the continent to leapfrog existing fossil-fuel energy sources and, in the process, cut greenhouse gas emissions and improve public health.

 

Africa has a huge untapped potential for generating clean energy, including enough hydroelectric power from its seven major river systems to serve the entire continent’s needs, as well as enormous potential for other energy sources such as solar, wind and geothermal, according to the study by the UN Environment Programme (UNEP) and the European Patent Office (EPO).

 

 

http://www.un.org/apps/news/story.asp?NewsID=44891&Cr=clean%20energy&Cr1=&utm_source=buffer&utm_medium=twitter&utm_campaign=Buffer&utm_content=buffer88f2c#.UZKoFEpNapB

[knocker]

A review of the relevance of the ‘CLOUD’ results and other recent observations to the possible effect of cosmic rays on the terrestrial climate

Abstract

The problem of the contribution of cosmic rays to climate change is a continuing one and one of importance. In principle, at least, the recent results from the CLOUD project at CERN provide information about the role of ionizing particles in ’sensitizing’ atmospheric aerosols which might, later, give rise to cloud droplets. Our analysis shows that, although important in cloud physics the results do not lead to the conclusion that cosmic rays affect atmospheric clouds significantly, at least if H₂SO₄ is the dominant source of aerosols in the atmosphere. An analysis of the very recent studies of stratospheric aerosol changes following a giant solar energetic particles event shows a similar negligible effect. Recent measurements of the cosmic ray intensity show that a former decrease with time has been reversed. Thus, even if cosmic rays enhanced cloud production, there would be a small global cooling, not warming.

 

 

http://link.springer.com/article/10.1007%2Fs00703-013-0260-x

[Gray-Wolf]

A review of the relevance of the ‘CLOUD’ results and other recent observations to the possible effect of cosmic rays on the terrestrial climate

 

http://link.springer.com/article/10.1007%2Fs00703-013-0260-x

 

 

I'm sure we all applaud the settling of this issue?

[knocker]

The Arctic oscillation, Climate change and the effects on precipitation in Israel

Abstract

The arctic oscillation (AO) has been found in previous studies to be a major synoptic factor affecting the climate of many regions in the high and mid-latitudes. This paper demonstrates the physical process by which the AO affects the climate of the Eastern Mediterranean basin, with a focus on precipitation in Israel as a case study.

 

It is shown that a trend of increasing AO is associated with a substantial decrease of winter precipitation from the Iberian Peninsula, though Italy, Greece, Turkey and Cyprus, as well as Lebanon, Syria and also the northern parts of Israel. Winter rain is slightly increased at the southern coast of the eastern half of the Mediterranean Sea. The immediate meteorological causes are shown to be a larger northerly component of the flow over the Mediterranean Sea, associated with a decreasing relative humidity and stability, except over the southern coast, where the air mass has the longest track over the relatively warm water. We suggest here that the observed changes in air flow that drives the precipitation trends can be explained by shifts in the AO that can be partially explained by increasing greenhouses gases. Results from the IPCC multi climate models show that the AO will continue to increase during the 21st century. This increase may lead to a continuation of the trends discussed here.

 

The importance of the analysis provided here is in pointing out the possibility that processes that have been predicted by global warming and changes in global circulation have already started to affect precipitation and major water resources in the Mediterranean basin.

 

 

http://www.sciencedirect.com/science/article/pii/S0169809513001282

[BornFromTheVoid]

Quantifying the consensus on anthropogenic global warming in the scientific literature

http://iopscience.iop.org/1748-9326/8/2/024024/article

 

We analyze the evolution of the scientific consensus on anthropogenic global warming (AGW) in the peer-reviewed scientific literature, examining 11 944 climate abstracts from 1991–2011 matching the topics 'global climate change' or 'global warming'. We find that 66.4% of abstracts expressed no position on AGW, 32.6% endorsed AGW, 0.7% rejected AGW and 0.3% were uncertain about the cause of global warming. Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming. In a second phase of this study, we invited authors to rate their own papers. Compared to abstract ratings, a smaller percentage of self-rated papers expressed no position on AGW (35.5%). Among self-rated papers expressing a position on AGW, 97.2% endorsed the consensus. For both abstract ratings and authors' self-ratings, the percentage of endorsements among papers expressing a position on AGW marginally increased over time. Our analysis indicates that the number of papers rejecting the consensus on AGW is a vanishingly small proportion of the published research.

 

[mikeworst]

I'm sure we all applaud the settling of this issue?

The last two sentences of the abstract comfirm the effect rather than dismiss it. I do believe this issue is far from settled.

"It is interesting that he cosmic ray hypothesis has to be tested by experiment in a mutibillion dollar facility whereas anything that supports the CAGW mantra is blindly accepted and it is up to everybody else to disprove it."

[knocker]

Signature of ocean warming in global fisheries catch

Marine fishes and invertebrates respond to ocean warming through distribution shifts, generally to higher latitudes and deeper waters. Consequently, fisheries should be affected by ‘tropicalization’ of catch^{1, 2, 3, 4} (increasing dominance of warm-water species). However, a signature of such climate-change effects on global fisheries catch has so far not been detected. Here we report such an index, the mean temperature of the catch (MTC), that is calculated from the average inferred temperature preference of exploited species weighted by their annual catch. Our results show that, after accounting for the effects of fishing and large-scale oceanographic variability, global MTC increased at a rate of 0.19 degrees Celsius per decade between 1970 and 2006, and non-tropical MTC increased at a rate of 0.23 degrees Celsius per decade. In tropical areas, MTC increased initially because of the reduction in the proportion of subtropical species catches, but subsequently stabilized as scope for further tropicalization of communities became limited. Changes in MTC in 52 large marine ecosystems, covering the majority of the world’s coastal and shelf areas, are significantly and positively related to regional changes in sea surface temperature⁵. This study shows that ocean warming has already affected global fisheries in the past four decades, highlighting the immediate need to develop adaptation plans to minimize the effect of such warming on the economy and food security of coastal communities, particularly in tropical regions^{6, 7}.

 

 

http://www.nature.com/nature/journal/v497/n7449/full/nature12156.html

[BornFromTheVoid]

The last two sentences of the abstract comfirm the effect rather than dismiss it. I do believe this issue is far from settled.

"It is interesting that he cosmic ray hypothesis has to be tested by experiment in a mutibillion dollar facility whereas anything that supports the CAGW mantra is blindly accepted and it is up to everybody else to disprove it."

 

Good job that so few blindly follow the CAGW mantra then, whatever that is.

[Methuselah]

The last two sentences of the abstract comfirm the effect rather than dismiss it. I do believe this issue is far from settled.

"It is interesting that he cosmic ray hypothesis has to be tested by experiment in a mutibillion dollar facility whereas anything that supports the CAGW mantra is blindly accepted and it is up to everybody else to disprove it."

So, what would you suggest they do?

[knocker]

World's melting glaciers making large contribution to sea rise

 

While 99 percent of Earth's land ice is locked up in the Greenland and Antarctic ice sheets, the remaining ice in the world's glaciers contributed just as much to sea rise as the two ice sheets combined from 2003 to 2009, says a new study led by Clark University and involving the University Colorado Boulder.

 

The new research found that all glacial regions lost mass from 2003 to 2009, with the biggest ice losses occurring in Arctic Canada, Alaska, coastal Greenland, the southern Andes and the Himalayas. The glaciers outside of the Greenland and Antarctic sheets lost an average of roughly 260 billion metric tons of ice annually during the study period, causing the oceans to rise 0.03 inches, or about 0.7 millimeters per year.

 

 

http://www.eurekalert.org/pub_releases/2013-05/uoca-wmg051513.php

Edited May 16, 2013 by knocker

[knocker]

We might have to revise our thinking on ancient sea levels and ice volumes.

 

World's biggest ice sheets likely more stable than previously believed Researchers show that high ancient shorelines do not necessarily reflect ice sheet collapse millions of years ago

 

For decades, scientists have used ancient shorelines to predict the stability of today's largest ice sheets in Greenland and Antarctica. Markings of a high shoreline from three million years ago, for example – when Earth was going through a warm period – were thought to be evidence of a high sea level due to ice sheet collapse at that time. This assumption has led many scientists to think that if the world's largest ice sheets collapsed in the past, then they may do just the same in our modern, progressively warming world.

However, a new groundbreaking study now challenges this thinking.

 

http://www.eurekalert.org/pub_releases/2013-05/cifa-wbi051613.php

Edited May 16, 2013 by knocker

[4wd]

Pacific Islands are growing not shrinking.

http://www.abc.net.au/news/2010-06-03/pacific-islands-growing-not-sinking/851738

"Eighty per cent of the islands we've looked at have either remained about the same or, in fact, gotten larger,"

 

[4wd]

Increased Antarctic snowfall reduces sea level rise.
http://onlinelibrary.wiley.com/doi/10.1002/grl.50559/abstract

Enhanced snowfall on the East Antarctic ice sheet is projected to significantly mitigate 21st century global sea level rise. In recent years (2009 and 2011), regionally extreme snowfall anomalies in Dronning Maud Land, in the Atlantic sector of East Antarctica, have been observed. It has been unclear, however, whether these anomalies can be ascribed to natural decadal variability, or whether they could signal the beginning of a long-term increase of snowfall. Here we use output of a regional atmospheric climate model, evaluated with available firn core records and gravimetry observations, and show that such episodes had not been seen previously in the satellite climate data era (1979). Comparisons with historical data that originate from firn cores, one with records extending back to the 18th century, confirm that accumulation anomalies of this scale have not occurred in the past ~60 years, although comparable anomalies are found further back in time. We examined several regional climate model projections, describing various warming scenarios into the 21st century. Anomalies with magnitudes similar to the recently observed ones were not present in the model output for the current climate, but were found increasingly probable toward the end of the 21st century.

[4wd]

Tundra not about to release methane

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature12129.html

 Warming initially accelerates decomposition^4, 5, 6, increasing nitrogen availability, productivity and woody-plant dominance^3, 7. However, these responses may be transitory, because coupled abiotic–biotic feedback loops that alter soil-temperature dynamics and change the structure and activity of soil communities, can develop^8, 9. Here we report the results of a two-decade summer warming experiment in an Alaskan tundra ecosystem. Warming increased plant biomass and woody dominance, indirectly increased winter soil temperature, homogenized the soil trophic structure across horizons and suppressed surface-soil-decomposer activity, but did not change total soil carbon or nitrogen stocks, thereby increasing net ecosystem carbon storage.

[4wd]

Trying to model Arctic ice loss results in even more inaccurate global predictions.

http://onlinelibrary.wiley.com/doi/10.1002/grl.50562/abstract?

 

[1] Climate change simulations are the output of enormously complicated models containing resolved and parameterized physical processes ranging in scale from microns to the size of the Earth itself. Given this complexity, the application of subjective criteria in model development is inevitable. Here we show one danger of the use of such criteria in the construction of these simulations, namely the apparent emergence of a selection bias between generations of these simulations. Earlier generation ensembles of model simulations are shown to possess sufficient diversity to capture recent observed shifts in both the mean surface air temperature as well as the frequency of extreme monthly mean temperature events due to climate warming. However, current generation ensembles of model simulations are statistically inconsistent with these observed shifts, despite a marked reduction in the spread among ensemble members that by itself suggests convergence towards some common solution. This convergence indicates the possibility of a selection bias based upon warming rate. It is hypothesized that this bias is driven by the desire to more accurately capture the observed recent acceleration of warming in the Arctic and corresponding decline in Arctic sea ice. However, this convergence is difficult to justify given the significant and widening discrepancy between the modeled and observed warming rates outside of the Arctic.

[knocker]

Can't remember if this has been posted before.

 

Distinctive climate signals in reanalysis of global ocean heat content

Abstract

[1] The elusive nature of the post-2004 upper ocean warming has exposed uncertainties in the ocean's role in the Earth's energy budget and transient climate sensitivity. Here we present the time evolution of the global ocean heat content for 1958 through 2009 from a new observation-based reanalysis of the ocean. Volcanic eruptions and El Niño events are identified as sharp cooling events punctuating a long-term ocean warming trend, while heating continues during the recent upper-ocean-warming hiatus, but the heat is absorbed in the deeper ocean. In the last decade, about 30% of the warming has occurred below 700 m, contributing significantly to an acceleration of the warming trend. The warming below 700 m remains even when the Argo observing system is withdrawn although the trends are reduced. Sensitivity experiments illustrate that surface wind variability is largely responsible for the changing ocean heat vertical distribution.

 

 

http://onlinelibrary.wiley.com/doi/10.1002/grl.50382/abstract

Edited May 17, 2013 by knocker

[knocker]

Historical and idealized climate model experiments: an intercomparison of Earth system models of intermediate complexity

 

Abstract. Both historical and idealized climate model experiments are performed with a variety of Earth system models of intermediate complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE and continue through to 2005. The standard simulations include changes in forcing from solar luminosity, Earth's orbital configuration, CO₂, additional greenhouse gases, land use, and sulphate and volcanic aerosols. In spite of very different modelled pre-industrial global surface air temperatures, overall 20th century trends in surface air temperature and carbon uptake are reasonably well simulated when compared to observed trends. Land carbon fluxes show much more variation between models than ocean carbon fluxes, and recent land fluxes appear to be slightly underestimated. It is possible that recent modelled climate trends or climate–carbon feedbacks are overestimated resulting in too much land carbon loss or that carbon uptake due to CO₂ and/or nitrogen fertilization is underestimated. Several one thousand year long, idealized, 2 × and 4 × CO₂ experiments are used to quantify standard model characteristics, including transient and equilibrium climate sensitivities, and climate–carbon feedbacks. The values from EMICs generally fall within the range given by general circulation models. Seven additional historical simulations, each including a single specified forcing, are used to assess the contributions of different climate forcings to the overall climate and carbon cycle response. The response of surface air temperature is the linear sum of the individual forcings, while the carbon cycle response shows a non-linear interaction between land-use change and CO₂ forcings for some models. Finally, the preindustrial portions of the last millennium simulations are used to assess historical model carbon-climate feedbacks. Given the specified forcing, there is a tendency for the EMICs to underestimate the drop in surface air temperature and CO₂ between the Medieval Climate Anomaly and the Little Ice Age estimated from palaeoclimate reconstructions. This in turn could be a result of unforced variability within the climate system, uncertainty in the reconstructions of temperature and CO₂, errors in the reconstructions of forcing used to drive the models, or the incomplete representation of certain processes within the models. Given the forcing datasets used in this study, the models calculate significant land-use emissions over the pre-industrial period. This implies that land-use emissions might need to be taken into account, when making estimates of climate–carbon feedbacks from palaeoclimate reconstructions.

 

 

http://www.clim-past.net/9/1111/2013/cp-9-1111-2013.pdf

[knocker]

Regional patterns and proximal causes of the recent snowpack decline in the Rocky Mountains, U.S.

Abstract

[1] We used a first-order, monthly snow model and observations to disentangle seasonal influences on 20th century,regional snowpack anomalies in the Rocky Mountains of western North America, where interannual variations in cool-season (November–March) temperatures are broadly synchronous, but precipitation is typically antiphased north to south and uncorrelated with temperature. Over the previous eight centuries, regional snowpack variability exhibits strong, decadally persistent north-south (N-S) antiphasing of snowpack anomalies. Contrary to the normal regional antiphasing, two intervals of spatially synchronized snow deficits were identified. Snow deficits shown during the 1930s were synchronized north-south by low cool-season precipitation, with spring warming (February–March) since the 1980s driving the majority of the recent synchronous snow declines, especially across the low to middle elevations. Spring warming strongly influenced low snowpacks in the north after 1958, but not in the south until after 1980. The post-1980, synchronous snow decline reduced snow cover at low to middle elevations by ~20% and partly explains earlier and reduced streamflow and both longer and more active fire seasons. Climatologies of Rocky Mountain snowpack are shown to be seasonally and regionally complex, with Pacific decadal variability positively reinforcing the anthropogenic warming trend.

 

 

http://onlinelibrary.wiley.com/doi/10.1002/grl.50424/abstract

Edited May 21, 2013 by knocker