Saturday, August 1, 2015

U.K. bogs - and drinking water - threatened by climate change

Scientists warn an entire eco-system 
is under threat from climate change

Birds, bugs and blanket bogs -- scientists warn an entire eco-system is under threat from climate change.

Several rare upland bird species are being put at risk together with other ecosystem functions by the effects of climate change on the UK's blanket bogs, ecologists at the University of York have discovered.

Image result for blanket bogsMost of our drinking water comes from these upland peats and several iconic bird species such as the dunlin, golden plover and red grouse depend on these wetland habitats for nesting and feeding.

The scientists warn that climate change threatens these habitats, not only from rising temperatures increasing peat decomposition, but also via altered rainfall patterns -- with summer droughts drastically affecting the blanket bog hydrology.

The study, which involved collaboration with British Trust for Ornithology, Aberystwyth University and the University of Leeds and part-funded by the RSPB, showed that the humble crane fly, more commonly known as 'daddy longlegs', is a crucial link in determining the impact of climate change on these peatland bird species.

The birds depend on the protein rich crane flies as food for chicks, but scientists have discovered that summer droughts, which are predicted to increase, will cause significant declines in crane flies and subsequently the bird species that depend on them.

Based on a peatland model developed at the University of York and latest climate change predictions, the researchers warn that by 2051-80 the dunlin could see a 50% decline in numbers, with the golden plover down 30% and the red grouse down by 15%, all driven by declining abundance of the birds' crane fly prey.  The findings, highlight the complex relationship between climate, bog habitats, insects, and birds.

It suggests that large-scale projects to restore degraded and eroded blanket bogs could be critical in securing the future of these internationally important bird populations, alongside both water supplies and the crucial role of blanket bogs as a carbon store.

Dr Andreas Heinemeyer from the Stockholm Environment Institute (SEI) based at the University of York, who developed the peatland model, said: "This is one of the first studies to follow this bug-to-bird link, down the food chain, between climate change and something happening to an entire eco-system with relevance to people."
Wetland Ecology:
Principles and Conservation
(Cambridge Studies in Ecology)

by Paul A. Keddy

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"There is a very strong relationship between the moisture of the peat and the survival of the larvae of the crane fly during summer. July and August are peak times: if it is too dry, the larvae just desiccate and die and are then not available for the bird chicks the following year.

"The crane fly link was made as part of several longer-term studies -- funded by The Natural Environment Research Council and Defra -- investigating blanket bog ecosystems across several UK upland sites, including the Yorkshire Dales, Peak District and North York Moors.Dr Heinemeyer, who is currently leading a £1m Defra-funded SEI project to further study the impacts of climate change and management on blanket bogs, said it wasn't only rare birds that were at risk from climate change.

"We might be in for big change. Not just in connection with our birds, but our drinking water as well," he added "If you end up being very dry as a blanket bog you store less water and your water quality seems to deteriorate as peat erodes and decomposes. So there seems to be a link, but it's not an easy link.

"It is a very messy picture as vegetation and bugs are also involved and everything works together like a jigsaw puzzle. If you change a piece, you will change others around it."

Dr Carroll, RSPB Conservation Scientist, said: "Our work shows that climate change could harm some of our most iconic upland bird species. The birds rely on crane flies for food during the breeding season, and the crane flies rely on the cool, wet conditions in blanket bogs.

"Large-scale peatland restoration projects such as the Sustainable Catchment Management Project run by United Utilities and RSPB are crucial in helping to make our blanket bogs resilient to climate change."

Story Source:  Materials provided by University of York.  Matthew J. Carroll, Andreas Heinemeyer, James W. Pearce-Higgins, Peter Dennis, Chris West, Joseph Holden, Zoe E. Wallage, Chris D. Thomas. Hydrologically driven ecosystem processes determine the distribution and persistence of ecosystem-specialist predators under climate change. Nature Communications, 2015

Friday, July 31, 2015

Five reasons to thank Plankton.

Five reasons to thank Plankton?

Okay, so not the character from Spongebob Squarepants.  As the article in the current issue of Nature magazine says,  "For too long Plankton have slaved away in obscurity, making the world a better place for generations of ungrateful humans. Until now. Find out how much you owe these little guys with ~  

Thursday, July 30, 2015

How accurate are climate model projections?

The Stockholm Resilience Center published a list of nine planetary boundaries in 2010 that is useful in understanding the current state of the global environment.  The nine include species extinction, global warming, fresh water use, land use and so on. (See THE GLOBAL ENVIRONMENT for a complete list with links to the latest research on each boundary.)

The Climate Change Boundary
Recent evidence suggests that the Earth, now passing 390 ppmv CO2 in the atmosphere, has already transgressed the planetary boundary and is approaching several Earth system thresholds. We have reached a point at which the loss of summer polar sea-ice is almost certainly irreversible. The nine planetary boundaries were developed as a project of the Stockholm Resilience Centre, founded in 2007, as a joint project of Stockholm University and the Beijer International Institute of Ecological Economics at The Royal Swedish Academy of Sciences. 

New study narrows the gap between climate models and reality

Climate models are used to estimate future global warming, and their accuracy can be checked against the actual global warming observed so far. Most comparisons suggest that the world is warming a little more slowly than the model projections indicate. Scientists have wondered whether this difference is meaningful, or just a chance fluctuation.

Dire Predictions,
Second Edition:
Understanding Climate Change

 by Michael E. Mann

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Dr Kevin Cowtan, of the Department of Chemistry at York, led an international study into this question and its findings are published in Geophysical Research Letters. The research team found that the way global temperatures were calculated in the models failed to reflect real-world measurements. The climate models use air temperature for the whole globe, whereas the real-world data used by scientists are a combination of air and sea surface temperature readings. Dr Cowtan said: "When comparing models with observations, you need to compare apples with apples.

"The team determined the effect of this mismatch in 36 different climate models. They calculated the temperature of each model earth in the same way as in the real world. A third of the difference between the models and reality disappeared, along with all of the difference before the last decade. Any remaining differences may be explained by the recent temporary fluctuation in the rate of global warming.

Dr Cowtan added: "Recent studies suggest that the so-called 'hiatus' in warming is in part due to challenges in assembling the data. I think that the divergence between models and observations may turn out to be equally fragile."

Dr Cowtan's primary field of research is X-ray crystallography and he is based in the York Structural Biology Laboratory in the University's Department of Chemistry. His interest in climate science has developed from an interest in science communication. This is his second major climate science paper. For this project, he led a diverse team of international researchers, including some of the world's top climate scientists.

Related stories:

Story Source:  Materials provided by University of York.  Kevin Cowtan, Zeke Hausfather, Ed Hawkins, Peter Jacobs, Michael E. Mann, Sonya K. Miller, Byron A. Steinman, Martin B. Stolpe, Robert G. Way. Robust comparison of climate models with observations using blended land air and ocean sea surface temperatures. Geophysical Research Letters, 2015

Tuesday, July 28, 2015

Sea-level in Chesapeake Bay rising faster than ocean

While most writers understand that ocean levels are rising and that cities like New Orleans, New York and others are at risk, this report stresses that water levels in the Chesapeake Bay are rising faster than the world-wide average.

Past and present sea levels in 
the Chesapeake Bay Region, USA
What this means for the future

Scientists write that sea-level rise (3.4 mm/yr) is faster in the Chesapeake Bay region than any other location on the Atlantic coast of North America, and twice the global average (1.7 mm/yr). They have found that dated interglacial deposits suggest that relative sea levels in the Chesapeake Bay region deviate from global trends over a range of timescales.

The Attacking Ocean:
The Past, Present,
and Future of
Rising Sea Levels

by Brian Fagan

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In a new article for GSA Today, authors Benjamin DeJong and colleagues write that sea-level rise (3.4 mm/yr) is faster in the Chesapeake Bay region than any other location on the Atlantic coast of North America, and twice the global average (1.7 mm/yr). They have found that dated interglacial deposits suggest that relative sea levels in the Chesapeake Bay region deviate from global trends over a range of timescales.

According to DeJong and colleagues, "Glacio-isostatic adjustment of the land surface from loading and unloading of continental ice is likely responsible for these deviations, but our understanding of the scale and timeframe over which isostatic response operates in this region remains incomplete because dated sea-level proxies are mostly limited to the Holocene and to deposits 80 ka or older."

To better understand glacio-isostatic control over past and present relative sea level, DeJong and colleagues applied a suite of dating methods to the stratigraphy of the Blackwater National Wildlife Refuge, one of the most rapidly subsiding and lowest-elevation surfaces bordering Chesapeake Bay. Their data indicate that the region was submerged at least for portions of marine isotope stage (MIS) 3 (about 30 to 60 thousand years ago), although, they note, multiple proxies suggest that global sea level was 40 to 80 meters lower than today.

Today, MIS 3 deposits are above sea level because they were raised by the Last Glacial Maximum forebulge, but decay of that same forebulge is causing ongoing subsidence. "These results," they write, "suggest that glacio-isostasy controlled relative sea level in the mid-Atlantic region for tens of thousands of years following retreat of the Laurentide Ice Sheet and continues to influence relative sea level in the region."

The study finds that isostatically driven subsidence of the Chesapeake Bay region will continue for millennia, exacerbating the effects of global sea-level rise and impacting the region's large population centers and valuable coastal natural resources.

Related stories:
Story Source:  Materials provided by Geological Society of America. Benjamin D. DeJong, Paul R. Bierman, Wayne L. Newell, Tammy M. Rittenour, Shannon A. Mahan, Greg Balco, Dylan H. Rood. Pleistocene relative sea levels in the Chesapeake Bay region and their implications for the next century.  GSA Today, 2015

Monday, July 27, 2015

Global population and energy use

Study is first to quantify global population
growth compared to energy use

Ending 400-year trend, global population growth has begun
to catch up with energy consumption during past 50 years.

If you've lived between the year 1560 and the present day, more power to you. Literally.

As global population grew from about 500 million in 1560 to more than 7 billion, energy usage outpaced population growth. This in effect increased the world's carrying capacity and allowed population to grow exponentially. Since 1963, however, the ratio between energy increases and population growth has narrowed. This change could restrict future population growth.

That's one of several conclusions reached by University of Nebraska-Lincoln ecologist John DeLong, who has co-authored the first study to quantify the relationship between human population growth and energy use on an international scale.

The study compiled several centuries' worth of data from Great Britain, the United States and Sweden to profile the dynamics between a skyrocketing population and its consumption of energy from fossil fuels and renewable sources.

The data showed that energy use has generally outpaced population growth over the last few hundred years. Each generation has thus produced more energy per person than its predecessor, the study reported, even as the population has climbed from about 500 million to more than 7 billion in the 450 years analyzed by the authors.

We Have to Change:
Taking Action to
Stabilize Climate Change,
 Curb Population Growth
 Including Immigration,
End Poverty, and the Liquidat

by Maria Ronay

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This increasing per capita energy supply has also hiked up Earth's carrying capacity -- the number of people it can sustain at equilibrium -- and allowed the population to grow at an ever-faster, or exponential, rate.

"Broadly speaking, no one's really (quantified) this," said DeLong, assistant professor of biological sciences. "But it was important, because there are studies going back decades that assume this kind of positive feedback loop: We grow, we expand our capacity to extract energy, and then we grow some more."

However, DeLong and colleague Oskar Burger also found that this dynamic has shifted in the decades following 1963, when the world's population was growing faster than ever before or since.

During the subsequent half-century, the ratio between energy increases and population growth has narrowed, with the former now aligning more closely to the latter. A 1:1 ratio would theoretically limit the planet's population to a linear rather than exponential growth rate.

"I do think this should challenge our assumptions about future population growth," DeLong said. "The study supports conventional wisdom to a degree, but it also reminds us that (abundant energy) is maybe not something that we can count on indefinitely.

"Our study sort of plays into a deep cultural philosophy that we have the creativity and ability to solve whatever problem comes our way. The evidence shows that, from an energy point of view, we've done that a lot. But maybe that's not a guarantee."

While analyzing the data, the researchers also spotted unexpected fluctuations in the population-energy relationship at certain points in history. After closer scrutiny, they discovered that per capita energy yields fluctuated during times of socio-economic and environmental upheaval: the Little Ice Age, the Industrial Revolution, World War I and II, the oil crises of the 1970s.

Though DeLong emphasized that the data will not allow researchers to determine whether this instability actually drove changes in energy use -- or vice versa -- he acknowledged that the overlaps warrant further study.

"It's a cautionary tale, perhaps," DeLong said. "The human socio-economic system is a complex one with a lot of moving parts. Those things are really unpredictable, but generally speaking, we think about complex systems as relying on a stable throughput of energy.

"I think the timing of those peaks in variability tells us that we should be thinking about this in two ways: how what other countries do influences the energy supply, and how to maintain those flows without generating downstream problems."

DeLong said the study's insights might also help inform and refine population projections. The United Nations currently projects, with 95 percent confidence, that Earth's population in the year 2100 will sit between 9 billion and 13 billion people.

"In the back of our minds, it definitely is a goal to make better, more mechanistic forecasts," said DeLong. "What we're saying is: Every other population on the planet depends on energy to fuel their activities and maintain their bodies. Ours must, too."

Related stories:
Story Source: Materials provided by University of Nebraska-Lincoln.  John P. DeLong, Oskar Burger. Socio-Economic Instability and the Scaling of Energy Use with Population Size. PLOS ONE, 2015

Wednesday, July 22, 2015


Our planet is a tremendously complex set of systems that is very confusing to the average citizen.  To make it simpler to understand the current state of the overall global environment, posts about the latest science found on reputable sites are listed below for each of the nine planetary systems identified in 2010 by the Stockholm Resilience Centre. 

After each category title is a brief explanation of the system as written by the Stockholm Centre.  The stories posted are based on hard, vetted science - not someone's personal opinion.  To be considered vetted, the story is evaluated by qualified scientists to ensure that correct scientific procedures have been followed and that all and any data is included whether or not it supports the study's conclusions.

The systems that scientists agree have deteriorated to or beyond a practical tipping point based on the latest science are highlighted in red.  

      The Sixth Extinction:
      An Unnatural History
      by Elizabeth Kolbert
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    • Change in biosphere integrity (biodiversity loss and species extinction)
  • Biogeochemical flows (phosphorus and nitrogen cycles)
    • The biogeochemical cycles of nitrogen and phosphorus have been radically changed by humans as a result of many industrial and agricultural processes. Nitrogen and phosphorus are both essential elements for plant growth, so fertilizer production and application is the main concern. Much of this new reactive nitrogen is emitted to the atmosphere in various forms rather than taken up by crops. When it is rained out, it pollutes waterways and coastal zones or accumulates in the terrestrial biosphere. Similarly, a relatively small proportion of phosphorus fertilizers applied to food production systems is taken up by plants; much of the phosphorus mobilized by humans also ends up in aquatic systems. These can become oxygen-starved as bacteria consume the blooms of algae that grow in response to the high nutrient supply. A significant fraction of the applied nitrogen and phosphorus makes its way to the sea, and can push marine and aquatic systems across ecological thresholds of their own.  One regional-scale example of this effect is the decline in the shrimp catch in the Gulf of Mexico's 'dead zone' caused by fertilizer transported in rivers from the US Midwest.
  • Atmospheric aerosol loading (microscopic particles in the atmosphere that affect climate and living organisms)
    • An atmospheric aerosol planetary boundary was proposed primarily because of the influence of aerosols on Earth's climate system. 
      • Aerosols play a critically important role in the hydrological cycle affecting cloud formation and global-scale and regional patterns of atmospheric circulation, such as the monsoon systems in tropical regions.
      • Aerosols have a direct effect on climate, by changing how much solar radiation is reflected or absorbed in the atmosphere. Shifts in climate regimes and monsoon systems have already been seen in highly polluted environments, giving a quantifiable regional measure for an aerosol boundary. 
      • Aerosols have adverse effects on many living organisms. Inhaling highly polluted air causes roughly 800,000 people to die prematurely each year. 
      • No limits to human effects on clouds
      • Climate change scientists must turn their attention to clean skies, experts urge
  • Introduction of novel entities (e.g. organic pollutants, radioactive materials, nanomaterials, and micro-plastics). 
    • Emissions of toxic and long-lived substances such as synthetic organic pollutants, heavy metal compounds and radioactive materials represent some of the key human-driven changes to the planetary environment. These compounds can have potentially irreversible effects on living organisms and on the physical environment. Even when the uptake and bioaccumulation of chemical pollution is at sub-lethal levels for organisms, the effects of reduced fertility and the potential of permanent genetic damage can have severe effects on ecosystems far removed from the source of the pollution. For example, persistent organic compounds have caused dramatic reductions in bird populations and impaired reproduction and development in marine mammals.