Category Archives: Oceans

Global warming “paused”? Its the oceans stupid (reprint)

Andrew Glikson of the ANU has a great piece on The Conversations today dealing with the “global warming paused” myth that is endlessly recycled by climate change deniers. Glikson makes a great point: by solely focusing on land temperature data,  faux-sceptics wave away the fact the planet’s oceans are warming and provide some of the strongest evidence for climate change. Some 90% of the heat is trapped in the world’s oceans: figure 3 below provides a stunning illustration of this fact. 

Fact check: has global warming paused? by Andrew Glikson

“The UN’s climate change chief, Rajendra Pachauri, has acknowledged a 17-year pause in global temperature rises, confirmed recently by Britain’s Met Office, but said it would need to last ‘30 to 40 years at least’ to break the long-term global warming trend.” – The Australian, Feb 22 2013

Since the onset of the industrial age (from 1750 AD) Earth’s atmosphere, surface and ocean temperatures have warmed. This is mainly due to the rise in greenhouse gases (CO2, CH4, N2O, O3, halocarbons, stratospheric water vapour from CH4) by a total of +3.06 Watt/m2. Other drivers include black carbon (+0.1 Watt/m2) and solar irradiance – the latter during the first half of the 20th century (+0.12 Watt/m2).

Warming was in part mitigated by emitted sulphur aerosols (direct effects -0.5 Watt/m2; cloud albedo effects -0.7 Watt/m2) and by land clearing (-0.2 Watt/m2).

Cyclic, regional and transient climate effects are related to the ENSO cycle, water vapour (whose concentration depends on air temperature) and volcanic events. The fastest warming occurs in the polar regions: this is where there is the biggest albedo (or reflectiveness) contrast between ice and water, and where little or no water vapour exists in the atmosphere.

The consequent warming trend, as measured by NASA, NOAA and Hadley-Met and analysed by Berkeley (see Figure 1), indicates a rise in average land temperature by about +1.5°C over the past 250 years, and about +0.9°C in the past 50 years. A sharp rise in temperatures from about 1975-1976 was related to both an accelerated rise in CO2 and a decrease in emission of SO2 from coal and oil due to clean air policies (see Figure 2). Cleaner air decreases the reflectiveness of the atmosphere, thus driving further warming.

Figure 1: Mean continent-ocean global warming since 1750 http://berkeleyearth.org/results-summary/

Following a sharp El Niño peak in 1998, since about 2000 a slowing down of the mean rate of global warming was related to a sharp increase in SO2 emission from coal mainly in China (see Figure 2), strong La Niña events and a low in the 11 years sun-spot cycle.

Figure 2: Anthropogenic sulphur dioxide emissions 1850-2005. http://www.atmos-chem-phys.net/11/1101/2011/acp-11-1101-2011.pdf

As some 90% of the global heat rise is trapped in the oceans (since 1950, more than 20×1022 joules), the ocean heat level reflects global warming more accurately than land and atmosphere warming. The heat content of the ocean has risen since about 2000 by about 4×1022 joules.

Figure 3: Build-up in Earth’s total heat content. http://www.skepticalscience.com/docs/Comment_on_DK12.pdf

The rise in land and atmosphere temperatures since about 1996 reflects a combination of greenhouse radiative forcing from 360 to 395ppm CO2 at rates of up to 2.54ppm/year (unprecedented since 55 million years ago), the ENSO cycle and 11-years sunspot cycle. Peak temperatures at around 2006 exceed any measured in the instrumental record.

Figure 4: NASA Land-ocean temperatures http://data.giss.nasa.gov/gistemp/graphs_v3/

To summarise, claims that warming has paused over the last 16 years (1997-2012) take no account of ocean heating.

At the root of the issue is the non-acceptance by some of the reality of the greenhouse effect, known since the 19th century and consistent with the basic laws of greenhouse gas radiative forcing and black body radiation.

Andrew Glikson does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.The Conversation

This article was originally published at The Conversation.
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The dead seas: will global warming usher in another mass extinction of sea life?

Under a green sky, details below

From Science Daily a report on the increasingly worrying state of the world’s oceans and the impact on sea life:

Three of the five largest extinctions of the past 500 million years were associated with global warming and acidification of the oceans — trends which also apply today, the scientists say in a new article in the journal Trends in Ecology and Evolution. 

Other extinctions were driven by loss of oxygen from seawaters, pollution, habitat loss and pressure from human hunting and fishing — or a combination of these factors.

“Currently, the Earth is again in a period of increased extinctions and extinction risks, this time mainly caused by human factors,” the scientists stated. 

While the data is harder to collect at sea than on land, the evidence points strongly to similar pressures now being felt by sea life as for land animals and plants…

The paper in question is behind the pay wall, I’m reading it:

Extinctions in ancient and modern seas. Trends in Ecology & Evolution, 2012; Paul G. Harnik, Heike K. Lotze, Sean C. Anderson, Zoe V. Finkel, Seth Finnegan, David R. Lindberg, Lee Hsiang Liow, Rowan Lockwood, Craig R. McClain, Jenny L. McGuire, Aaron O’Dea, John M. Pandolfi, Carl Simpson, Derek P. Tittensor.

The abstract:

In the coming century, life in the ocean will be confronted with a suite of environmental conditions that have no analog in human history. Thus, there is an urgent need to determine which marine species will adapt and which will go extinct. Here, we review the growing literature on marine extinctions and extinction risk in the fossil, historical, and modern records to compare the patterns, drivers, and biological correlates of marine extinctions at different times in the past. Characterized by markedly different environmental states, some past periods share common features with predicted future scenarios. We highlight how the different records can be integrated to better understand and predict the impact of current and projected future environmental changes on extinction risk in the ocean.

For those more curious, I’d suggest the “Under a green sky: Global Warming, the Mass Extinctions of the Past, and What They Can Tell Us About Our Future” by Peter Ward. It’s a good popular introduction to the topic.

It recounts how scientists came to understand major extinction events, and discusses the role of increased levels of Co2 and ocean acidification in past extinction events. In particular Ward discusses the Permian-Triassic Extinction Event (PET) that occurred around 250 million years ago, when over 90% of all life vanished.

The PET is also referred to as the “Great dying”.

The new normal

This:

Faster climate change, kill, kill kill!

Who's being provocative huh?

How’s that for a “provocative” and “alarmist” blog post title? Huh? Huh?

While many of us would be more comfortable thinking we have decades – if not centuries – to act on climate change, it would appear the planet has other ideas:

“…For the past 30 years, satellites have been tracking a stunning decline in the sea ice and snow cover blanketing the Arctic. Now, new research has found that the thinning and melting sea ice is having a much more significant impact on global climate change than was previously thought.”

DeSmogBlog reports record temperatures in the Canadian Arctic:

“…While world media have been distracted by cold temperatures in Europe (December averages in the U.K. were 5.2°C [9.4°F] below normal), a vast pocket over northeastern Canada has been hitting heights that were not just unprecedented but, until this year, unimaginable.

As Bob Henson reports at the NCAR & UCAR Currents, the Canadian low Arctic has been unseasonably, unreasonably balmy, with the largest anomaly rising to 21°C [37.8°F] above normal. Hudson Bay and the waters around Baffin Island remained open well beyond usual, suggesting that the risk for an extraordinarily low summer ice season is built into the works…”

Climate change is a non-linear process: it is very possible climate will undergo significant changes in a relatively short time frame:

“….nonlinear process spurred by an increasing forcing and amplifying feedbacks is better characterized by the doubling time for the rate of mass disintegration, rather than a linear rate of mass change. If the doubling time is as short as a decade, multi-meter sea level rise could occur this century. Observations of mass loss from Greenland and Antarctica are too brief for significant conclusions, but they are not inconsistent with a doubling time of a decade or less. The picture will become clearer as the measurement record lengthens.”

Change: It needs to happen. It must happen. It is going to happen

It’s easy to feel overwhelmed by this information.

Michael Tobis (MT) over at “Only in it for the gold” has been musing on the scale of the challenges we face:

“….do you really think the world is handling its challenges well? Do you see any immediate prospect of improvement?

First of all, food production is practiced as an extractive industry, dependent on depleting aquifers, petroleum and natural gas. That’s unsustainable by definition.

Secondly, resource allocation is inequitable, we are running out resources, and the implicit promise of universal development is looking to the less developed world like a sham about now.

Thirdly, despite the fact that our economies are grossly overheated, the idiot bankers have gotten us in a situation where if we don’t resume growth our whole organizational pattern will collapse.

Fourthly, after some decades of improvement, the momentum has resumed toward xenophobia, isolationism, and ethnic blame. In particular, Christianity and Islam are about as friendly now as they were during the crusades.

Fifth, the cheap petroleum is running out and the next cheapest replacements double the carbon burden of the atmosphere and oceans, which leads us to sixth, the atmosphere and oceans are already about as full of carbon as we can reasonably risk.

Seventh, in the middle of all this nobody gives a rat’s behind about nuclear proliferation which we all used to lose a lot of sleep about.

Eighth, the world’s major power is controlled by obstructionist elements and is redeveloping a fascist streak that had been in remission. The fact that Africa is dying of AIDS and hunger, and that species extinction is accelerating, now seem to disturb nobody’s sleep anymore amid all this. Did I miss any?

The good news? Well, Twitter is pretty cool. So is my iPhone; so are movies on demand which after decades of promises have finally arrived. But somehow I don’t think that sort of thing is enough…”

Although someone did manage to cheer MT up with a great quote from science fiction author Bruce Sterling:

Our capacities are tremendous.

Eventually, it is within our technical ability to create factories that clean the air as they work, cars that give off drinkable water, industry that creates parks instead of dumps, or even monitoring systems that allow nature to thrive in our cities, neighbourhoods, lawns and homes. An industry that is not just “sustainable,” but enhances the world. The natural world should be better for our efforts and our ingenuity. It’s not too much to ask.

You and I will never live to see a future world with those advanced characteristics. The people who will be living in it will pretty much take it for granted, anyway. But that is a worthy vision for today’s technologists: because that is wise governance for a digitally conquered world. That is is not tyranny. That is legitimacy.

Without vision, the people perish. So we need our shimmering, prizes, goals to motivate ourselves, but the life is never in the prize. The living part, the fun part, is all in the wrangling. Those dark cliffs looming ahead — that is the height of your achievement.

We need to leap into another way of life. The technical impetus is here. We are changing, but to what end? The question we must face is: what do we want? We should want to abandon that which has no future. We should blow right through mere sustainability. We should desire a world of enhancement. That is what should come next. We should want to expand the options of those who will follow us. We don’t need more dead clutter to entomb in landfills. We need more options.

It needs to happen. It must happen. It is going to happen

Did it also cheer me?

Perhaps.

Dead seas

Where are your monuments, your battles, martyrs?
Where is your tribal memory? Sirs,
in that gray vault. The sea. The sea
has locked them up. The sea is History. [1]

The most terrifying thing I’ve read all year

“…Scientists may have found the most devastating impact yet of human-caused global warming — a 40% decline in phytoplankton since 1950 linked to the rise in ocean sea surface temperatures.  If confirmed, it may represent the single most important finding of the year in climate science.”

The oceans are dying.

Faster than we anticipated.

Abstract of the Nature paper that spells it out:

“…In the oceans, ubiquitous microscopic phototrophs (phytoplankton) account for approximately half the production of organic matter on Earth. Analyses of satellite-derived phytoplankton concentration (available since 1979) have suggested decadal-scale fluctuations linked to climate forcing, but the length of this record is insufficient to resolve longer-term trends. Here we combine available ocean transparency measurements and in situ chlorophyll observations to estimate the time dependence of phytoplankton biomass at local, regional and global scales since 1899. We observe declines in eight out of ten ocean regions, and estimate a global rate of decline of ~1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. We conclude that global phytoplankton concentration has declined over the past century; this decline will need to be considered in future studies of marine ecosystems, geochemical cycling, ocean circulation and fisheries.”

To translate: 

  • “Marine ecoystems” refers to the fact that phytoplankton are crucial to the food chain
  • “Geochemical cycling” refers to the fact that phytoplankton generate about 50% of the oxygen produced by plants. They also absorb CO2 as they grow and reproduce (and where does that CO2 stay, well….)
  • “Fisheries” refers to the fact that we may see the extincton of species we depend upon for food.

[1] Derek Walcott, The Sea is History

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