Category Archives: Climate

Regime Shift for Permafrost Arctic Permafrost Thawing

Nowhere is the climate changing faster than in the Arctic. The region is warming at about twice the rate of the global average, with atmospheric temperature anomalies as much as 13 degrees Fahrenheit above normal reported in January.

Permafrost becomes especially vulnerable to these rapid changes, creating land subsidence, habitat change, and a potentially catastrophic release of carbon and methane as the once-frozen organic matter decomposes.

Arctic permafrost: the big thaw

Much of the terrestrial Arctic permafrost currently remains well below freezing.  At current rates of warming, scientists estimate it could take another 70 years for these frozen soils to fully melt.

Depending on the emissions scenario over the coming decades, researchers project anywhere from a 30 to 70 percent decline in near-surface permafrost by the end of the century. Our current emissions trajectory being the high end of that estimate, according to research cited Adam Wernick in a  Public Radio International article:

If 70 percent of the permafrost thaws, scientists expect to lose 130 to 160 billion tons of carbon into the atmosphere by the end of this century,” writes Adam Wernick. “To put that in perspective, in 2013 the United States emitted 1.4 billion tons of carbon from fossil fuel combustion and cement production.

Thawing permafrost represents a potential “tipping point” for runaway climate change. As more permafrost melts, more methane and CO2 are released into the atmosphere, increasing temperatures, causing more permafrost to melt, releasing more greenhouse gasses –  a relatively sudden and abrupt oscillation into a self-amplifying feedback loop.

A “regime change” for permafrost below shallow Arctic lakes

A study accepted for publication this week in the journal Geophysical Research Letters indicates an ongoing “regime shift” is underway in sub-lake permafrost. The soil below these shallow Arctic lakes is naturally warmer and is already thawing, as the following press release from the American Geophysical Union explains:

New research shows permafrost below shallow Arctic lakes is thawing as a result of changing winter climate.

Joint Release:

  • American Geophysical Union
  • University of Alaska Fairbanks
  • U.S. Geological Survey

16 June 2016

Warmer winters combined with an increase in snowfall during the last 30 years have limited the growth of seasonal lake ice. In response, lakebed temperatures of Arctic lakes less than 1 meter (3 feet) deep have warmed by 2.4 degrees Celsius (4.3 degrees Fahrenheit) during the past three decades, and during five of the last seven years, the mean annual lakebed temperature has been above freezing.

These rates of warming are similar to those observed in terrestrial permafrost, yet those soils are still well below freezing and thaw is not expected for at least another 70 years. However, a regime shift in lake ice is leading to sub-lake permafrost thaw now.

Since permafrost underneath lakes is generally warmer than the surrounding terrestrial permafrost, rising temperatures in the lakebeds make permafrost thaw sooner than beneath surrounding dry land. These lakes may cover 20 to 40 percent of the landscape in vast areas of Arctic lowlands.

“During the 1970s, late winter lake ice thickness measurements commonly exceeded 2 meters (6.5 feet) in northern Alaska. Such thick ice growth helps to limit sub-lake permafrost thaw by freezing the sediments solid each winter. However, during winter field surveys over the last decade, lake ice has typically only grown to 1.5 meters (5 feet) thick, and has been as thin as 1.2 meters (4 feet),” said Christopher Arp, research assistant professor at the University of Alaska Fairbanks (UAF) Water and Environmental Research Center and lead author of the new study accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

These drastic reductions in lake ice, caused by changes in winter climate, are the primary reason that shallow lakebed temperatures are warming and the permafrost below them is thawing.

Interactions and feedbacks among climate, permafrost, and hydrology underscore the complexity of forecasting change in the Arctic. For example, thinner lake ice may help fish overwintering, or it may help the oil industry since they need lake water to build winter ice roads. However, sub-lake permafrost thaw will likely unlock a portion of the permafrost carbon pool and potentially release this carbon in the form of greenhouse gasses.

These findings also highlight the importance of conducting winter fieldwork in the Arctic.

“Arctic lakes and ponds are typically ice covered for nine months of the year, but research on them typically occurs during the short Arctic summer. To more fully understand Arctic lake dynamics and to document the changes we have observed requires also doing fieldwork under often harsh conditions during the cold and dark arctic winter,” said Benjamin Jones of the U.S. Geological Survey in Anchorage and co-author of the new study.

“With further thawing of sub-lake permafrost there is a good chance that the ground will subside, increasing the lake depth and accelerating further permafrost thawing. In contrast, the warming on the land may increase the protective vegetation layer and delay thawing of permafrost outside of lakes,” said Vladimir Romanovsky of the UAF Geophysical Institute and co-author of the new study.

With increasingly warmer and snowier winters yielding thinner lake ice, shallow lakes will likely continue to warm, Arp said.


The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 60,000 members in 139 countries. Join the conversation on FacebookTwitterYouTube, and our other social media channels.


Image credit: Anthony Kendall, courtesy Flickr

My Inconvenient Truth : Reflections on Al Gore’s Impact, Ten Years On

In May of 2006, Al Gore’s now-classic climate change documentary “An Inconvenient Truth was released. The movie won an Oscar in the Featured Documentary category, and Gore was co-recipient of the Nobel Peace Prize, along with the U.N. Intergovernmental Panel on Climate Change (IPCC). The nominating committee recognized Gore and the IPCC “for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change.”

For many, it was as if Al Gore invented global warming. Or that global warming invented Al Gore, I’m not sure which. What is certain is the enormous impact the movie and Gore’s advocacy through the years had on raising awareness about the, well, inconvenient truth of climate change.

To be perfectly candid, I think “raising awareness” is among the canon of over-hyped phrases like “paradigm shift.” Meaningful at their core, these idioms are overused, often with a pretentious tinge, to the point of diffusing much of their impact and credibility. This is ironic given that we live in transformative times ourselves, witness to a global paradigm shift of raised awareness.

It’s tricky.

I read Gore’s 1992 nonfiction book “Earth in the Balance,” so I was no stranger to his environmental advocacy. But “An Inconvenient Truth” brought the issue to the forefront of public consciousness like little did before or since (except the changing climate itself), for better and worse. I can only speak anecdotally, but I believe Gore is likely the most famous straw man alive — and for some, also the most reviled. He raised awareness about global warming so masterfully that he has become synonymous with it, often not in a good way.

This may sound like I’m being critical of his work. If I do admit some ambivalence, it is not for lack of admiration and inspiration for what Gore has done and is doing in the public campaign to push for climate action. I’ve heard Gore speak on several occasions. I’ve gone through his Climate Leadership training. He is passionate and sincere about his work.

Perhaps my ambivalence is directed more toward the climate change narrative itself than to Gore’s engagement with it. It is a narrative too often oversimplified, tortured beyond all recognition of civility and imbued with an ideological fervor that has little to do with the task at hand.

And it’s for all this that I’d like to take the opportunity of the 10-year anniversary of “An Inconvenient Truth” to thank Al Gore for changing my life.

An inconvenient journey

I can’t say exactly when I first learned about climate change, but it was long before Gore’s movie. I’d also read other cautionary works like Jeremy Rifkin’s early work “Entropy,” Paul Ehrlich’s “Population Bomb,” Robert Heinberg’s “The Party’s Over” and The Club of Rome’s “Limits to Growth,” among others. 

From a very young age I was a budding Malthusian.

But while contemplating this doom, I also found great joy in the beauty of the world around me. My ambivalence was my own.

I acquired the domain name “globalwarmingisreal.com” several years earlier, but after seeing “An Inconvenient Truth” in May of 2006 I decided to focus my efforts on what I cared about most and launched the official blog GlobalWarmingisReal.com (GWIR). It was a humble launch, but 10 years on it is still going strong.

What’s more, I’ve had an opportunity to temper my general Malthusian worldview with a sense of guarded optimism. While I’ve endured over the years the expected heaving of hate and fear, I’ve also seen firsthand the hard work of many talented, passionate and brilliant people focused on moving the world toward a better future. That’s what gives me inspiration to engage with these pathfinders, tell their story and each day try a little bit harder to help light the way.

“Few will have the greatness to bend history itself,” Robert Kennedy said in a 1966 speechin South Africa, “but each of us can work to change a small portion of events. And in the total of all those acts will be written the history of this generation.” We all have within us the power to send out “tiny ripples of hope” that will converge into a mighty current of sweeping renewal.

Few of us have the influence or reach of Al Gore, but we all have a responsibility to pursue the harder path before us, so that others may follow. Each in our own way.

Is Al Gore the reason I am concerned about global warming? No. But Gore and his documentary helped set me out on the path I am on today, and upon which I intend to remain for the rest of my life

“My heart is moved by all I cannot save:
so much has been destroyed
I have to cast my lot with those
who age after age, perversely,
with no extraordinary power,
reconstitute the world.”
— Adrienne Rich

Image credit: Woody Hibbard, courtesy flickr

This post originally published on TriplePundit

Suffocating the Ocean : Climate and Ocean Health

Ocean breathing

From the shallows down to its yawning depths, the ocean gets its oxygen from the surface, supplied either by the atmosphere or from the release of oxygen in phytoplankton through photosynthesis.

Scientists have long known that one expected consequence from a warming climate is a gradual drop in the amount of oxygen dissolved into ocean waters as they absorb extra heat trapped in the atmosphere by increasing concentrations of greenhouse gas.

Warming surface waters absorb less heat. The oxygen that does take into the surface waters has a harder time circulating down into the deeper water due to the expansion of the warmer upper layers. This expansion makes the surface water lighter than the water below it, less likely to sink and circulate.

As with all climate phenomena, ocean oxygen concentration at the surface is in constant flux from the natural variability of warming and cooling. A particularly cold winter in the North Pacific, for example, will soak up a lot of oxygen, which then mixes deep into the ocean from the naturally occurring circulation patterns.

On the other hand, an unusually warm period stifles oxygen update and circulation, which can lead to “dead zones” where fish and marine life cannot survive.

“Oxygen varies naturally in the ocean quite substantially,” said Matthew Long,  a scientist at the National Center for Atmospheric Research (NCAR) and lead author of new research into the impact of a warming climate impacts oxygen levels in the ocean.

“Without any human-driven climate change we could expect oxygen levels at a particular location to go up and down in such a way that low levels may be persistent for a number of years, followed by a period of high levels,” Long said in a recent press release

Historically, teasing out this natural variability in ocean oxygen from warming-driven loss has been difficult, Long explains. “Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life,” he said.

“Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it’s been challenging to attribute any deoxygenation to climate change. This new study tells us when we can expect the impact from climate change to overwhelm the natural variability.”

Ocean oxygenation levels and climate change

Research raises new concerns for ocean health

Distinguishing ocean deoxygenation caused by natural variability from climate change is the focus of Long’s research, published this week in Global Biogeochemical Cycles, a journal of the American Geophysical Union.

In a study titled Finding forced trends in oceanic oxygen” Long and his colleagues found that ocean deoxygenation from climate change can already be detected in the southern Indian Ocean and parts of the eastern tropical Pacific and Atlantic basins. The research also determined that a more widespread loss of oxygen from climate change will likely be seen between 2030 and 2040.

Long’s team used the output from more than two dozen model runs of NCAR’s Community Earth System Model for the years 1920 to 2100 , with each subsequent run starting with tiny variations in air temperature.  As each model run progressed, these small differences grew and expanded, affording a set of simulations useful for studying questions about change and variability.

Using these simulations to study dissolved oxygen, the simulations guided the researchers on past oxygen concentration variability. With this foundation they could then determine when ocean deoxygenation is likely to become more intense than at any point in the modeled past.

With this same dataset, the research team mapped ocean oxygen levels, visually representing where waters are oxygen rich at the same time that others are oxygen starved. From this mapping researchers could determine distinct patterns between natural variability and climate change in ocean oxygenation. What’s more, the maps will serve as a useful resource for deciding where to place oxygen monitoring equipment for ongoing research, crucial for sharpening the picture of ocean health and change.

“We need comprehensive and sustained observations of what’s going on in the ocean to compare with what we’re learning from our models and to understand the full impact of a changing climate,” Long said.

One more assault on ocean health

This new study adds yet one more offense to the health of the world’s oceans. Increased uptake of CO2 from the atmosphere causes ocean acidification,  rapidly warming waters imperil coral reefs across the globe, highlighted by recent news that 93 percent of the Great Barrier Reef has been impacted by the most severe coral bleaching event on record.

Add to all this the persistent pollution and plastic waste in the oceans.

As oxygen levels become more pronounced, the resulting dead zones could have serious affects on marine ecosystems and sustainable fisheries.

The ocean itself is the living, breathing source of life on earth. We ignore its future health and vitality at our own peril.

Featured image credit: Narcah, courtesy flickr
Graph courtesy of AGU