Showing posts with label sulfur. Show all posts
Showing posts with label sulfur. Show all posts

Monday, August 26, 2013

The astounding global warming impact on our oceans that will reduce cloud cover and bring tears to your eyes

Ocean acidification will just not kill significant ocean ecosystems, but add even more to global warming

by David Spratt




Another significant global warming positive feedback that will add even more to future temperature rises has been identified by researchers from the Max Planck Institute for Meteorology in Hamburg, Germany. End result: Perhaps another half a degree of warming this century.

New research just published in Nature Climate by Katharine Six and her colleagues shows that as oceans become more acidic (by absorbing increasing volumes of carbon dioxide from the atmosphere to form carbonic acid), the amount of a compound called dimethylsulphide (DMS) in the ocean decreases.

So what? The researchers say that marine DMS emissions are the largest natural source of atmospheric sulphur, and changes in their strength have the potential to alter the Earth’s radiation budget. They establish:
… observational-based relationships between pH (acidity) changes and DMS concentrations to estimate changes in future DMS emissions …
Global DMS emissions decrease by about 18(±3)% in 2100 compared with pre-industrial times as a result of the combined effects of ocean acidification and climate change. The reduced DMS emissions induce a significant additional radiative forcing, of which 83% is attributed to the impact of ocean acidification, tantamount to an equilibrium temperature response between 0.23 and 0.48 K. Our results indicate that ocean acidification has the potential to exacerbate anthropogenic warming through a mechanism that is not considered at present in projections of future climate change.
Shorthand: by reducing DMS production in the oceans, acidification could add up to another half a degree of warming this century. And that's on top of the 4-to-6 degrees Celsius warming that is now being projected for the emissions path on which the world now seems stubbornly stuck.

Reporting on the latest finding, Eliot Barford in Nature explains that:
Acidification would lead certain marine organisms to emit less of the sulphur compounds that help to seed the formation of clouds and so keep the planet cool.
Atmospheric sulphur, most of which comes from the sea, is a check against global warming. Phytoplankton — photosynthetic microbes that drift in sunlit water — produces a compound called dimethylsulphide (DMS). Some of this enters the atmosphere and reacts to make sulphuric acid, which clumps into aerosols, or microscopic airborne particles. Aerosols seed the formation of clouds, which help cool the Earth by reflecting sunlight.
But this idea that warming will have a DMS impact is not new. As far back as 1994, James Lovelock and Lee Kump published a paper in Nature on Failure of climate regulation in a geophysiological model, with conclusions far more eye-watering that this new research.

Lovelock has explained in The Revenge of Gaia that as the ocean surface temperature warms to a temperature over 12 degrees Celsius (°C), "a stable layer of warm water forms on the surface that stays unmixed with the cooler, nutrient rich waters below". This purely physical property of ocean water, he says, "denies nutrients to the life in the warm layer, and soon the upper sunlit ocean water becomes a desert".

This chlorophyll-deprived, azure-blue water is currently found predominantly in the tropics, which lacks the richness of the marine life of the darker, cooler oceans. In this nutrient-deprived water, ocean life cannot prosper and, according to Lovelock, soon "the surface layer is empty of all but a limited … population of algae". Algae (such as phytoplankton), which constitute most of the ocean’s plant life, are the world’s greatest carbon sinks, devouring carbon dioxide while releasing DMS, which is transformed into an aerosol that contributes to greater cloud formation and, hence, affects weather patterns. The warmer seas and fewer algae that Lovelock predicts are likely to reduce cloud formation and further enhance positive climate feedbacks.

This process should be distinguished from the phenomenon of green, red, or brown algal blooms, which can occur in fresh and marine environments when phytoplankton assume very dense concentrations due to an excess of nutrients in the water. The dead organic material becomes food for bacteria, which can deprive the water of oxygen, destroying the local marine life and creating a dead zone.

Because algae thrive in ocean water below 10°C, the algae population reduces as the climate warms. Lovelock says that severe disruption of the algae–DMS relation would signal spiralling climate change. Lovelock and Kump’s modelling of climate warming and regulation published in Nature in supported this view:
[A]s the carbon dioxide abundance approached 500 parts per million, regulation began to fail and there was a sudden upward jump in temperature. The cause was the failure of the ocean ecosystem. As the world grew warmer, the algae were denied nutrients by the expanding warm surface of the oceans, until eventually they became extinct. As the area of ocean covered by algae grew smaller, their cooling effect diminished and the temperature surged upwards.
Lovelock and Kump (1994) Figure 2
According to Lovelock, the end-result was a temperature rise of 8°C above pre-industrial levels, which would result in the planet being habitable only from Melbourne to the South Pole (going south), and from northern Europe, Asia, and Canada to the North Pole (going north).

On current projections and a high fossil-fuel-use pathway, 500 parts per million carbon dioxide (ppm CO2) in the atmosphere will be exceeded by mid-century. Already the concentration has just hit 400 ppm CO2 (compared to the pre-industrial level of 280 ppm CO2), greenhouse emissions are still growing each year and are currently adding more than 2 ppm CO2 annually.

And the reaction to this astounding paper? In personal correspondence, Kump says their research was generally ignored – and never refuted. I guess that's how cognitive dissonance expresses itself.

Of course reduced DMS production is not the only, or most imminent impact of global warming on our oceans.

In 2013, Frieler, Meinshausen et al. showed that “preserving more than 10% of coral reefs worldwide would require limiting warming to below +1.5°C (atmosphere–ocean general circulation models (AOGCMs) range: 1.3–1.8°C) relative to pre-industrial levels”. Obviously at less than 10%, the reefs would be remnant and reef systems as we know them today would be a historical footnote. Contrast this finding of impacts at 1.5°C or warming, compared to the current, forlorn attempts to hold warming to not more tha 2°C!

Already, the data suggests the global area of reef systems has already been reduced by half. A sober discussion of coral reef prospects can be found in Roger Bradbury’s “A World Without Coral Reefs” and Gary Pearce’s “Zombie reefs as a harbinger for catastrophic future”. Bradbury’s article opening is sharp:
“It’s past time to tell the truth about the state of the world’s coral reefs, the nurseries of tropical coastal fish stocks. They have become zombie ecosystems, neither dead nor truly alive in any functional sense, and on a trajectory to collapse within a human generation. There will be remnants here and there, but the global coral reef ecosystem — with its storehouse of biodiversity and fisheries supporting millions of the world’s poor — will cease to be.”
And on all of this, not one word will be uttered during Australia's current national election campaign. I mean, who in their right mind thinks elections are about our collective future?


David Spratt studied at Australian National University.
David co-authored the book Climate Code Red (2008).  

Above article was posted earlier at ClimateCodeRed.org

References

- Rising ocean acidity will exacerbate global warming, Eliot Barford, August 25, 2013

- Global warming amplified by reduced sulphur fluxes as a result of ocean acidification, Six et al., August 25, 2013

- Limiting global warming to 2 °C is unlikely to save most coral reefs, Frieler et al., September 16, 2012
http://www.nature.com/nclimate/journal/v3/n2/full/nclimate1674.html

- The Revenge of Gaia, James Lovelock, 2006
http://en.wikipedia.org/wiki/The_Revenge_of_Gaia

- Failure of climate regulation in a geophysiological model, James Lovelock and Lee Kump, June 30, 1994
http://www.nature.com/nature/journal/v369/n6483/abs/369732a0.html

Related

- Arctic melt hits food security in bitter taste of life on a hotter planet, by David Spratt, July 11, 2013

- Climate Plan

Thursday, January 10, 2013

Anthropogenic Arctic Volcano can calm climate

by Paul Beckwith
Paul Beckwith, B.Eng, M.Sc. (Physics),
Ph.D. student (Climatology) and
Part-time Professor, University of Ottawa
 

Rational decision making requires realistic risk assessments of alternatives. Humanity is now choosing default door A, which is no change in behavior with fossil fuel energy sourcing and a continuance of rapidly rising anthropogenic greenhouse gas emissions (GHGs).

Abrupt collapse of Arctic albedo due to collapsing terrestrial snow cover (area dropping 17.6% per decade for past three decades) and collapse of sea ice cover (area dropping 49% below 1979 to 2000 long term average) is occurring (NOAA 2012 Arctic Report Card from last week).

The destination is an ice free condition within a few years (by 2015 with PIOMAS volume projections); well before the 30 to 60 year timeframe of the most sophisticated climate change models which are a big FAIL on sea ice. The risk (= probability of occurrence x significance of occurrence) is enormous through door A. Probability of occurrence is 50% within 3 years and significance to human farming, water availability, temperatures and weather extremes is clearly massive.

A recent widely-respected DARA report states that Today climate change is directly/indirectly reducing global GDP by 1.6% and attributing to 400,000 human deaths globally (to increase to 2.6% and 500,000 in about 20 years). A recent UN report is warning of global food shortages in 2013. There is no end in sight to the U.S. drought (climate models predict such droughts can last 20 or 30 years, hopefully they are wrong as they are with sea ice).

I prefer door B - create an Anthropogenic Arctic volcano to calm the climate. Give me two large airplanes with pilots, some sulfur in solution, and a few large nozzles from your local ski hill; they are not needed anyway since the ski industry has estimated losses of $1 Billion over the last decade (about 8% of total revenues); adaptation to zip lining and water parks is possible. With this equipment I will fly into the stratosphere (above the weather) near the North Pole and spread sulfur dust/aerosols to reflect incoming sunlight and rapidly cool the Arctic for several years. This will restore sea ice, straighten the jet streams, and restore a “normal” climate.

Very little sulfur is needed relative to huge emissions from smokestacks into the lower atmosphere from coal burning power plants. It will work; powerful erupting volcanoes that aim upwards (like Pinatubo in 1991) and not sideways (like Mt. St. Helens in 1980) have cooled the climate by a degree or more for 2 to 3 years. They do this by injecting sulfur up into the upper atmosphere, like our aircraft will do.

Door B has two important sub-doors, B-Bad and B-Good. Door B-B is using the sulfur injections to calm climate and continuing the fossil-fuel energy sourcing with rapidly accelerating GHGs. This door will be a false reprieve since the GHGs will continue to rapidly acidify the ocean and destroy the base of the food chain; by the way, ocean phytoplankton levels have dropped 40% since 1950.

Wikipedia image: UN jet with humanitarian relief supplies
Luckily for us, Door B-G exists. Door B-G is using the sulfur injections to calm climate and rapidly slashing fossil-fuel energy sourcing by ramping up conservation, efficiency renewables as fast as is humanly possible; I am talking about retooling on the scale of the Manhattan Project or Apollo Programs. Or even having a U.S. president (or a Chinese one) getting all the CEOs of car manufacturers together in a room and telling them they will produce no cars for 3 years, only wind turbines, geothermal heat exchangers, and solar panels. Is this possible? In WWII the meeting occurred and for the next 3 years only war materials were produced. And keep in mind the industrial revolution of World War Two ushered in one of longest eras of prosperity humanity has known.

Of course there is a caveat with Door B-G. We must start the sulfur injections when the sun rises in the Arctic in the spring in early 2013. Waiting for more sea ice collapse will decrease the odds of success at obtaining Arctic snow cover and sea ice regrowth. Give me a plane, pilot, nozzle, and sulfur and I can calm the climate.

Originally posted January 10, 2013, at Sierra Club Canada; posted here with author's permission

Thursday, September 27, 2012

The atmosphere's shift of state and the origin of extreme weather events

By Andrew Glikson, Australian National University
Andrew Glikson, earth and
paleo-climate scientist at
Australian National University

The linear nature of global warming trends projected by the IPCC since 1990 and as late as 2007 (see Figure 1) has given the public and policy makers an impression there is plenty of time for economies to convert from carbon-emitting industries to non-polluting utilities.

Paleo-climate records suggest otherwise. They display abrupt shifts in the atmosphere/ocean/cryosphere system, as manifest in the ice core records of the last 800,000 years. This suggests high sensitivity of the climate system to moderate changes in radiative forcing, whether triggered by changes in solar radiation energy or the thermal properties of greenhouse gases or aerosols. In some instances these shifts have happened over periods as short as centuries to decades, and even over a few years.


Figure 1: Global surface temperature rise trajectories for the 21st century under varying carbon emission scenarios portrayed by the IPCC AR4 2007. A2 represents the business-as-usual scenario consistent with currently rising global emissions. IPCC

Examples of abrupt climate shifts are the 1470 years-long Dansgaard-Oeschger intra-glacial cycles, which were triggered by solar signals amplified by ocean currents, and the “younger dryas” cold interval, which occured when interglacial peaks resulted in extensive melting of ice and cooling of large ocean regions by melt water.

The last glacial termination (when large-scale melting of ice occurred between about 18,000 to 11,000 years ago) is attributed to transient solar pulsations of 40–60 Watt/m2 affecting mid-northern latitudes. This led to a ~6.5+/-1.5 Watt/m2 rise in mean global atmospheric energy level, which meant a mean global temperature rise of ~5.0+/-1.0 degrees Celsius and sea level rise of 120 meters (see Figure 2).


Figure 2: Comparison between radiative forcing levels of (1) the Pliocene (~400 ppm CO2; T ~ 2-3 degrees C; Sea level 25+/-12 meters higher than pre-industrial); (2) the last Glacial Termination (~6.5+/-1.5 Watt/m2; ~5.0+/-1.0 degrees C; SL rise 120 meters) and (3) Anthropogenic 1750-2007 warming (1.66 Watt/m2 + 1.35 Watt/m2 – the latter currently masked by sulphur aerosols). Modified after Hansen et al 2008

As shown in Figure 2, anthropogenic carbon emission and land clearing since 1750 have raised the atmospheric energy level by +1.66 Watt/m2. Once the masking effect of industrial sulphur aerosols is taken into account. This totals ~3.0 Watt/m2, namely near half the radiative forcing associated with the last glacial termination.

Compounding the major rise in radiative forcing over the last ~260 years is the rate of greenhouse gas (GHG) rise. This has averaged ~0.5ppm CO2 per year since 1750. That’s more than 40 times the rate during the last glacial termination, which was 0.012ppm CO2 per year. The current CO2 rise rate – 2ppm a year – is the fastest recorded for the Cainozoic (the period since 65 million years ago) (see Figure 3).


Figure 3: Relations between CO2 rise rates and mean global temperature rise rates during warming periods, including the Paleocene-Eocene Thermal Maximum, Oligocene, Miocene, glacial terminations, Dansgaard-Oeschger (D-O) cycles and the post-1750 period. Glikson

We have seen this scale and rate of radiative forcing, in particular since the 1970s, expressed by intensification of the hydrological cycle, heat waves and hurricanes around the globe. It imparts a new meaning to the otherwise little-defined term, “tipping point”.

Between 1900 and 2000, the ratio of observed to expected extremes in monthly mean temperatures has risen from ~1.0 to ~3.5. From about 1970 the Power Dissipation Index (which combines storm intensity, duration, and frequency) of North Atlantic storms increased from ~1.0 to ~2.7-5.5 in accord with tropical sea surface temperatures which rose by about 1.0 degree Celsius.

Coumou and Rahmstorf (of the Potsdam climate impacts research institute) state:
The ostensibly large number of recent extreme weather events has triggered intensive discussions, both in- and outside the scientific community, on whether they are related to global warming. Here, we review the evidence and argue that for some types of extreme — notably heat waves, but also precipitation extremes — there is now strong evidence linking specific events or an increase in their numbers to the human influence on climate. For other types of extreme, such as storms, the available evidence is less conclusive, but based on observed trends and basic physical concepts it is nevertheless plausible to expect an increase.
Hansen et al analysed the distribution of anomalous weather events relative to the 1951–1980 base line, displaying a shift toward extreme heat events (see Figure 4). The authors observe:
hot extreme[s], which covered much less than 1% of Earth’s surface during the base period (1951-1980), now typically [cover] about 10% of the land area. It follows that we can state, with a high degree of confidence, that extreme anomalies such as those in Texas and Oklahoma in 2011 and Moscow in 2010 were a consequence of global warming because their likelihood in the absence of global warming was exceedingly small.


Figure 4: Hansen et al 2012 calculate the seasonal mean and standard deviation at each grid point for this period, and then normalize the departures from the mean, obtaining a Gaussian bell-shaped distribution. They plot a histogram of the values from successive decades, getting a sense for how much the climate of each decade departed from that of the initial baseline period. The shift in the mean of the histogram is an indication of the global mean shift in temperature, and the change in spread gives an indication of how regional events would rank with respect to the baseline period. Hansen et al

The consequences for the biosphere of accelerating climate change are discussed by Baronsky et al in the following terms:
Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence.

Climates found at present on 10–48% of the planet are projected to disappear within a century, and climates that contemporary organisms have never experienced are likely to cover 12–39% of Earth. The mean global temperature by 2070 (or possibly a few decades earlier) will be higher than it has been since the human species evolved.
At 400ppm CO2, potential climate conditions have reached levels which last existed in the peak Pliocene epoch (5.3-2.6 million years ago). Given an increase in extreme weather events under conditions of +0.8C, an even higher rate of extreme events is expected under conditions of +2.0C currently shielded by industrially emitted sulphur aerosols.

Current trends in the frequency and intensity of extreme weather events are evident globally (see Figure 5). In the USA, the number of meteorological, hydrological and climatological events rose from about 20-40 per year during 1980-1988, to about 40-80 per year during 1989-2005, to between 70-100 per year after 2006, consistent with global rise in the frequency of extreme weather events.


Figure 5: Global frequency of natural disaster impacts and associated human and economic losses from the 1970s to 1990s. World Meteorological Organization, 2006 http://www.nrcan.gc.ca/earth-sciences/climate-change/community-adaptation/assessments/378

James Hansen states:
There is still time to act and avoid a worsening climate, but we are wasting precious time. We can solve the challenge of climate change with a gradually rising fee on carbon collected from fossil-fuel companies, with 100% of the money rebated to all legal residents on a per capita basis. This would stimulate innovations and create a robust clean-energy economy with millions of new jobs. It is a simple, honest and effective solution.
New solar technologies promise to provide a large part of the answer. Time is of the essence.

Andrew Glikson is Honorary Professor at the Geothermal Energy Centre of Excellence, The University of Queensland, and a Visiting Fellow at the Australian National University.


The Conversation



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