The Climate Change Factor in Extreme Weather Events

The 4 Mile Creek area near Boulder, Colorado, was devastated by an extreme rain/flood event in September 2013.

An op-ed in today’s New York Times, How We Know It Was Climate Change,  is well worth reading. The author of the op-ed, N.S. Diffenbaugh, lays out the rationale for a link between climate change and extreme weather events. Diffenbaugh’s op-ed is based on a journal article written by himself and others that was published in the Proceedings of the National Academy of Sciences (PNAS – 3/17), Quantifying the influence of global warming on unprecedented extreme climate events.

Both the op-ed and the PNAS article are essential reads for the new year.

A Year of Weather for 2013 Via an 8-minute Video

Watch this video to see the day by day weather of 2913 compressed into 8 minutes. The  video content comes from American, European, and Japanese satellite imagery. EUMETSAT, the European Organisation for the Exploitation of Meteorological Satellites, compiled the video, complete with audio commentary. NASA’s Blue Marble project is the source for the video background.

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Rising Seas and Carbon Footprint Visualizations

National Geographic "Rising Seas" map of projected North American shoreline change from ice melt. Map from: http://tiny.cc/xc0z9w
National Geographic “Rising Seas” map of projected North American shoreline change from ice melt. Map from: http://tiny.cc/xc0z9w

New sets of interactive maps help to visualize both the impact of rising seas on the world’s coastlines and U.S household carbon footprints.National Geographic has posted a set of world-wide interactive maps that show new coastal outlines resulting from the premise of all ice melting and thus raising sea level approximately 216 feet. As noted by the authors:

There are more than five million cubic miles of ice on Earth, and some scientists say it would take more than 5,000 years to melt it all. If we continue adding carbon to the atmosphere, we’ll very likely create an ice-free planet, with an average temperature of perhaps 80 degrees Fahrenheit instead of the current 58.

Continuing on the topic of adding carbon to the atmosphere, University of Berkeley researchers, Christopher Jones and Daniel Kammen, looked at the spatial distribution of U.S. household carbon footprints. The researchers first point out the obvious in that carbon footprints in densely populated areas are typically low because of smaller residences, shorter commutes, and the availability of mass transit. Here’s the catch though – the suburbs have an unusually large carbon footprint. In fact the footprint is so large that it negates the “green” urban core. As Jones and Kammen summarize:

As a policy measure to reduce GHG emissions, increasing population density appears to have severe limitations and unexpected trade-offs. In suburbs, we find more population- dense suburbs actually have noticeably higher HCF, largely because of income effects. Population density does correlate with lower HCF when controlling for income and household size; however, in practice population density measures may have little control over income of residents. Increasing rents would also likely further contribute to pressures to suburbanize the suburbs, leading to a possible net increase in emissions. As a policy measure for urban cores, any such strategy should consider the larger impact on surrounding areas, not just the residents of population dense communities themselves. The relationship is also log−linear, with a 10-fold increase in population density yielding only a 25% decrease in HCF. Generally, we find no evidence for net GHG benefits of population density in urban cores or suburbs when considering effects on entire metropolitan areas.

U.S. Average Annual Household Carbon Footprint by Household. "Source: UC Berkeley CoolClimate Network, Average Annual Household Carbon Footprint (2013)"
U.S. Average Annual Household Carbon Footprint by Household. “Source: UC Berkeley CoolClimate Network, Average Annual Household Carbon Footprint (2013)”

 

Dead Mud Encroaches On To Maine’s Shellfish Flats

“Dead mud” is not a geologic term that I had heard before. But it well describes a geologic event that may have catastrophic implications for coastal areas as oceans continue to acidify.

The Maine coastal areas are being particularly hard hit with dead mud:

The spread of “dead mud” among Maine’s shellfish flats could have disastrous implications for clammers, lobstermen, oyster farmers and others whose livelihoods depend on healthy coastal ecosystems.

Mark Green, an oyster grower and marine science professor at St. Joseph’s College in Standish, defines dead mud:

The darker muds and sulfur-rich muds don’t have any clams, and those are the flats that have lower pH levels. Places where historically there have been great harvests that supported clammers for decades, you now see water quality changes that are reflected in the mud.” The more acidic the water, the lower the pH.

In the following video, Prof. Mark Green further explains ocean acidification and how it affects marine life:
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Human Influence On The Climate System Is Unmistakable

The Intergovernmental Panel on Climate Change‘s (IPCC) much awaited report, the Fifth Assessment Report (AR5), concludes that scientists are 95% certain that humans are the “dominant cause” of global warming since the 1950s. A policy makers’ summary for AR5, IPCC’s latest report on physical evidence for climate change, was released today. The full report will be released on September 30th.

As noted in IPCC’s 9.27.2013 press release on the AR5:

Human influence on the climate system is clear. This is evident in most regions of the globe, a new assessment by the Intergovernmental Panel on Climate Change (IPCC) concludes.

 

It is extremely likely that human influence has been the dominant cause of the observed warming

since the mid-20th century. The evidence for this has grown, thanks to more and better observations, an improved understanding of the climate system response and improved climate models.

 

Warming in the climate system is unequivocal and since 1950 many changes have been observed throughout the climate system that are unprecedented over decades to millennia. Each of  the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850, reports the Summary for Policymakers of the IPCC Working Group I

assessment report, Climate Change 2013: the Physical Science Basis, approved on Friday by member governments of the IPCC in Stockholm, Sweden.

 

“Observations of changes in the climate system are based on multiple lines of independent evidence. Our assessment of the science finds that the atmosphere and ocean have warmed, the amount of snow and ice has diminished, the global mean sea level has risen and the concentrations of greenhouse gases have increased,” said Qin Dahe, Co-Chair of IPCC Working Group I.

Thomas Stocker, the other Co-Chair of Working Group I said: “Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.”

 

 

“Global surface temperature change for the end of the 21st century is projected to be likely to exceed 1.5°C relative to 1850 to 1900 in all but the lowest scenario considered, and likely to exceed 2°C for the two high scenarios,” said Co-Chair Thomas Stocker. “Heat waves are very likely to occur

more frequently and last longer. As the Earth warms, we expect to see currently wet regions receiving more rainfall, and dry regions receiving less, although there will be exceptions,” he added.

 

Projections of climate change are based on a new set of four scenarios of future greenhouse gas concentrations and aerosols, spanning a wide range of possible futures. The Working Group I report assessed global and regional-scale climate change for the early, mid-, and later 21st century.

 

 

“As the ocean warms, and glaciers and ice sheets reduce, global mean sea level will continue to rise, but at a faster rate than we have experienced over the past 40 years,” said Co-Chair Qin Dahe. The report finds with high confidence that ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and

2010. 

The Anthropocene Is Here

The last 250 years of human history have vastly changed out planet. During this time, human activities have greatly transformed geologically significant conditions and processes. The change is so immense that many geologists now refer to our current time as the Anthropocene – a word coined in 2000 by Eugene Stoermer and Paul Crutzen, a Nobel-winning Dutch chemist. The word “Anthropocene” is derived from the Greek anthropos for ‘human’ and Greek kainos, meaning ‘new’ or ‘recent’, and thus it basically means the human-dominated time of recent earth history. Anthropocene is not yet an official geological time scale term. The  International Commission on Stratigraphy is now considering recognizing the Anthropocene as a geological epoch and their decision on its inclusion is slated for 2016. In the meantime, ‘Anthropocene’ appears profusely in the geological literature – the publisher Elsevier has even started a new aca­demic journal titled Anthropocene.

A video, Welcome to the Anthropocene, is a good intro into the proposed epoch. It’s part of:

a collaborative project being run by researchers and communicators that aims to improve our ‘collective understanding of the Earth system’. The online project combines high-level scientific data with visualisations to help communicate the global geological and environmental impacts of human behaviour over the last 250 years.

Watch the full video with related content here: http://www.richannel.org/welcome-to-the-anthropocene

Siberian Cave Climate Records Indicate Permafrost Melt

Climate records from Siberian caves suggest an impending permafrost thaw and a resulting global warming acceleration.

Permafrost regions cover 24% of the northern hemisphere land surface, and hold an estimated 17,000 Gt of organic carbon. Thawing releases CO2 and CH4, creating positive feedback during greenhouse warming.

The researchers, led by Gideon Henderson at the University of Oxford’s Department of Earth Sciences, studied speleothem records from the caves to identify periods where temperatures were above freezing. Speleothems, such as stalactites and stalagmites, form when water seeps through cracks in cave walls, dissolving minerals which precipitate in the air filled cave.

‘Cave temperatures usually approximate the local mean annual air temperature’ says Anton Vaks, the paper’s lead author. ‘When they drop below 0 degrees, the rock above and around the cave freezes, and speleothem growth stops.’

By dating the speleothems and comparing their ages to existing climate records, it is possible to identify the degree of warming which caused the permafrost to melt. New results from Ledyanaya Lenskaya Cave, Eastern Siberia, extend previous records to one million years, and show major deposition of speleothems at around one million years and 400,000 years ago.

‘Both episodes occurred when global temperatures increased 1.5°C ± 0.5 above the pre-industrial level’ says Vaks, ‘showing that this degree of warming is a tipping point for continuous permafrost to start thawing.’

Global temperatures are currently around 0.7 degrees above pre-industrial level, with current models suggesting that a warming of 1.5°C ± 0.5 will be achieved within 10-30 years.

This paper will be presented at the Geological Society’s forthcoming William Smith Meeting, held on 25-27 June,  – a meeting that celebrates the 100th anniversary of the beginning of modern dating methods used in the earth sciences. (From: The Geological Society of London. “Siberian caves warn of permafrost meltdown.”Alpha Galileo Foundation, 19 Jun. 2013. Web. 21 Jun. 2013.)

First Intact Samples Collected From An Antarctic Subglacial Lake

wissard camp
Source: WISSARD Image of the Day.

The Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) field team drilled through 800 m of ice and intersected Subglacial Lake Whillans on 28 January 2013 at 0500 h. The team sampled mud and water from the floor of the subglacial lake, making this the first time that clean whole samples have been recovered from an Antarctic subglacial lake. Water analyses will be made for dissolved minerals and living cells. Sediment cores taken from the lake bed should provide scientists with data on the lake’s formation history and microbial inhabitants.

The WISSARD project team is also looking at ice dynamics. Live Science posted a quote from Ross Powell of the University of Northern Illinois, one of WISSARD’s 13 principal investigators regarding ice dynamics.  “Lake Whillans is just one of a few hundred interconnected lakes,” said Powell, “and radar observations have revealed that it fills and drains in a five-to-10-year cycle. We want to find out what causes these cycles. And knowing more about ice dynamics is important to better understand the effects global warming might have on the Antarctic continent. Thanks to WISSARD, we will be able for the first time to use real field data as input in our glacialogical models.”

DISCOVER Magazine has a science journalist, Douglas Fox, in Antarctica on assignment as the WISSARD Embedded Journalist. Read more of his experience with the project team at: DISCOVER.

Climate Change Impact on Earth Surface Systems

As Congress continues to stonewall on climate change legislation, I think that a recent article published in the Perspectives section of Nature Climate Change, The impacts of climate change on terrestrial Earth surface systems, is worth contemplating. The authors, Jasper Knight and Stephan Harrison, argue that “… at present, governments’ attempts to limit greenhouse-gas emissions through carbon cap-and-trade schemes and to promote renewable and sustainable energy sources are probably too late to arrest the inevitable trend of global warming. Instead, there are increasingly persuasive arguments that government and institutional focus should be on developing adaption policies that address and help mitigate against the negative outcomes of global warming, rather than carbon trading and cataloguing greenhouse-gas emissions”.

Don’t think that the authors suggest for us to just walk away from the greenhouse-gas emission and global warming problem, though. What they are advocating is a more inclusive strategy for dealing with global warming, one that includes understanding and managing the impacts of climate change on the dynamics of Earth surface systems – systems that include glaciers, rivers, mountains and coasts. These systems supply resources such as soil and water, and as such are critical components to life on earth. And, as we just witnessed with Superstorm Sandy, some of these systems, such as coastal and river systems, are vital in alleviating the impact of catastrophic weather events.

The major problem with immediately incorporating earth surface system data into a global warming management response is that earth surface systems operate on a much longer time scale than elements of the biosphere. To mitigate the time dilemma, there is potential in looking at earth surface system responses to past climatic events. Knight and Harrison note that, “…for instance, climate cooling during the Little Ice Age in Europe (~ad 1550–1850) had significant impacts on the sediment yields of mountain, fluvial and slope systems, particularly in marginal regions already predis­posed to be climatically sensitive to changes in temperature and pre­cipitation patterns, including their seasonality”.

In any event, currently, most Earth surface systems are not regularly monitored regarding climate change. This is a huge policy omission, both nationally and internationally, because Earth surface system dynamics are a major part of the landscape response to climate change, and these systems function on multinational spatial scales that play into sustainable resource management. It is going to take a large-scale effort by scientists, governments, and most importantly, citizens to make sure that the response to global warming includes understanding and managing the impacts of climate change on the dynamics of Earth surface systems. It’s long past time to get to work.