The AMOC is back in the news following a recent Ocean Sciences meeting.  This update adds to the theme Oceans Make Climate. Background links are at the end, including one where chief alarmist M. Mann claims fossil fuel use will stop the ocean conveyor belt and bring a new ice age.  Actual scientists are working away methodically on this part of the climate system, and are more level-headed.  H/T GWPF for noticing the recent article in Science Ocean array alters view of Atlantic ‘conveyor belt’  By Katherine Kornei Feb. 17, 2018 . Excerpts with my bolds.

The powerful currents in the Atlantic, formally known as the Atlantic meridional overturning circulation (AMOC), are a major engine in Earth’s climate. The AMOC’s shallower limbs—which include the Gulf Stream—transport warm water from the tropics northward, warming Western Europe. In the north, the waters cool and sink, forming deeper limbs that transport the cold water back south—and sequester anthropogenic carbon in the process. This overturning is why the AMOC is sometimes called the Atlantic conveyor belt.

Last week, at the American Geophysical Union’s (AGU’s) Ocean Sciences meeting here, scientists presented the first data from an array of instruments moored in the subpolar North Atlantic. The observations reveal unexpected eddies and strong variability in the AMOC currents. They also show that the currents east of Greenland contribute the most to the total AMOC flow. Climate models, on the other hand, have emphasized the currents west of Greenland in the Labrador Sea. “We’re showing the shortcomings of climate models,” says Susan Lozier, a physical oceanographer at Duke University in Durham, North Carolina, who leads the $35-million, seven-nation project known as the Overturning in the Subpolar North Atlantic Program (OSNAP).

The research and analysis is presented by Dr. Lozier et al. in this publication Overturning in the Subpolar North Atlantic Program: A New International Ocean Observing System Images above and text excerpted below with my bolds.

For decades oceanographers have assumed the AMOC to be highly susceptible to changes in the production of deep waters at high latitudes in the North Atlantic. A new ocean observing system is now in place that will test that assumption. Early results from the OSNAP observational program reveal the complexity of the velocity field across the section and the dramatic increase in convective activity during the 2014/15 winter. Early results from the gliders that survey the eastern portion of the OSNAP line have illustrated the importance of these measurements for estimating meridional heat fluxes and for studying the evolution of Subpolar Mode Waters. Finally, numerical modeling data have been used to demonstrate the efficacy of a proxy AMOC measure based on a broader set of observational data, and an adjoint modeling approach has shown that measurements in the OSNAP region will aid our mechanistic understanding of the low-frequency variability of the AMOC in the subtropical North Atlantic.

Finally, we note that while a primary motivation for studying AMOC variability comes from its potential impact on the climate system, as mentioned above, additional motivation for the measure of the heat, mass, and freshwater fluxes in the subpolar North Atlantic arises from their potential impact on marine biogeochemistry and the cryosphere. Thus, we hope that this observing system can serve the interests of the broader climate community.

In summary, while modeling studies have suggested a linkage between deep-water mass formation and AMOC variability, observations to date have been spatially or temporally compromised and therefore insufficient either to support or to rule out this connection.

Current observational efforts to assess AMOC variability in the North Atlantic.

The U.K.–U.S. Rapid Climate Change–Meridional Overturning Circulation and Heatflux Array (RAPID–MOCHA) program at 26°N successfully measures the AMOC in the subtropical North Atlantic via a transbasin observing system (Cunningham et al. 2007; Kanzow et al. 2007; McCarthy et al. 2015). While this array has fundamentally altered the community’s view of the AMOC, modeling studies over the past few years have suggested that AMOC fluctuations on interannual time scales are coherent only over limited meridional distances. In particular, a break point in coherence may occur at the subpolar–subtropical gyre boundary in the North Atlantic (Bingham et al. 2007; Baehr et al. 2009). Furthermore, a recent modeling study has suggested that the low-frequency variability of the RAPID–MOCHA appears to be an integrated response to buoyancy forcing over the subpolar gyre (Pillar et al. 2016). Thus, a measure of the overturning in the subpolar basin contemporaneous with a measure of the buoyancy forcing in that basin likely offers the best possibility of understanding the mechanisms that underpin AMOC variability. Finally, though it might be expected that the plethora of measurements from the North Atlantic would be sufficient to constrain a measure of the AMOC within the context of an ocean general circulation model, recent studies (Cunningham and Marsh 2010; Karspeck et al. 2015) reveal that there is currently no consensus on the strength or variability of the AMOC in assimilation/reanalysis products.

In addition we have a recent report from the United Kingdom Marine Climate Change Impacts Partnership (MCCIP) lead author G.D. McCarthy Atlantic Meridional Overturning Circulation (AMOC) 2017.

Figure 1: Ten-day (colours) and three month (black) low-pass filtered timeseries of Florida Straits transport (blue), Ekman transport (green), upper mid-ocean transport (magenta), and overturning transport (red) for the period 2nd April 2004 to end- February 2017. Florida Straits transport is based on electromagnetic cable measurements; Ekman transport is based on ERA winds. The upper mid-ocean transport, based on the RAPID mooring data, is the vertical integral of the transport per unit depth down to the deepest northward velocity (~1100 m) on each day. Overturning transport is then the sum of the Florida Straits, Ekman, and upper mid-ocean transports and represents the maximum northward transport of upper-layer waters on each day. Positive transports correspond to northward flow.

The RAPID/MOCHA/WBTS array (hereinafter referred to as the RAPID array) has revolutionized basin scale oceanography by supplying continuous estimates of the meridional overturning transport (McCarthy et al., 2015), and the associated basin-wide transports of heat (Johns et al., 2011) and freshwater (McDonagh et al., 2015) at 10-day temporal resolution. These estimates have been used in a wide variety of studies characterizing temporal variability of the North Atlantic Ocean, for instance establishing a decline in the AMOC between 2004 and 2013.

Summary from RAPID data analysis

MCCIP reported in 2006 that:

• a 30% decline in the AMOC has been observed since the early 1990s based on a limited number of observations. There is a lack of certainty and consensus concerning the trend;
• most climate models anticipate some reduction in strength of the AMOC over the 21st century due to increased freshwater influence in high latitudes. The IPCC project a slowdown in the overturning circulation rather than a dramatic collapse.And in 2017 that:
• a substantial increase in the observations available to estimate the strength of the AMOC indicate, with greater certainty, a decline since the mid 2000s;
• the AMOC is still expected to decline throughout the 21st century in response to a changing climate. If and when a collapse in the AMOC is possible is still open to debate, but it is not thought likely to happen this century.

And also that:

• a high level of variability in the AMOC strength has been observed, and short term fluctuations have had unexpected impacts, including severe winters and abrupt sea-level rise;
• recent changes in the AMOC may be driving the cooling of Atlantic ocean surface waters which could lead to drier summers in the UK.

Conclusions

• The AMOC is key to maintaining the mild climate of the UK and Europe.
• The AMOC is predicted to decline in the 21st century in response to a changing climate.
• Past abrupt changes in the AMOC have had dramatic climate consequences.
• There is growing evidence that the AMOC has been declining for at least a decade, pushing the Atlantic Multidecadal Variability into a cool phase.
• Short term fluctuations in the AMOC have proved to have unexpected impacts, including being linked
  with severe winters and abrupt sea-level rise.

Background:

Climate Pacemaker: The AMOC

Evidence is Mounting: Oceans Make Climate

Mann-made Global Cooling

 

 

Climates are locally defined according to their weather patterns combining temperature and precipitation. Those two variables determine the flora and fauna to survive and flourish in any locale. A number of posts here support the theme that Oceans Govern Climate, and this is another one, summarizing the findings from a new paper published in Nature Communications Pronounced centennial-scale Atlantic Ocean climate variability correlated with Western Hemisphere hydroclimate by Thirumalai et al. 2018. Below is an overview from Science Daily followed by excerpts from the paper with my bolds. (Note:  SST refers to sea surface temperatures, SSS refers to sea surface salinity, and GOM means Gulf of Mexico.)

Science Daily Rainfall and ocean circulation linked in past and present

Research conducted at The University of Texas at Austin has found that changes in ocean currents in the Atlantic Ocean influence rainfall in the Western Hemisphere, and that these two systems have been linked for thousands of years.

The findings, published on Jan. 26 in Nature Communications, are important because the detailed look into Earth’s past climate and the factors that influenced it could help scientists understand how these same factors may influence our climate today and in the future.

“The mechanisms that seem to be driving this correlation [in the past] are the same that are at play in modern data as well,” said lead author Kaustubh Thirumalai, postdoctoral researcher at Brown University who conducted the research while earning his Ph.D. at the UT Austin Jackson School of Geosciences. “The Atlantic Ocean surface circulation, and however that changes, has implications for how the rainfall changes on continents.”

Thirumalai et al. 2018 Abstract:

Surface-ocean circulation in the northern Atlantic Ocean influences Northern Hemisphere climate. Century-scale circulation variability in the Atlantic Ocean, however, is poorly constrained due to insufficiently-resolved paleoceanographic records.

Here we present a replicated reconstruction of sea-surface temperature and salinity from a site sensitive to North Atlantic circulation in the Gulf of Mexico which reveals pronounced centennial-scale variability over the late Holocene. We find significant correlations on these timescales between salinity changes in the Atlantic, a diagnostic parameter of circulation, and widespread precipitation anomalies using three approaches: multiproxy synthesis, observational datasets, and a transient simulation.

Our results demonstrate links between centennial changes in northern Atlantic surface-circulation and hydroclimate changes in the adjacent continents over the late Holocene. Notably, our findings reveal that weakened surface-circulation in the Atlantic Ocean was concomitant with well-documented rainfall anomalies in the Western Hemisphere during the Little Ice Age.

Here we address this shortfall and reconstruct SST and SSS variability over the last 4,400 years using foraminiferal geochemistry in marine sediments cored from the Garrison Basin (26°40.19′N,93°55.22′W, (purple circle in diagrams above), northern GOM. We make inferences about past changes in Loop Current strength by identifying time periods in our reconstruction where synchronous decreases in SST and SSS are interpreted as periods with a weaker Loop Current due to reduced eddy penetration over that period and vice versa. Thus, we assess the spatial heterogeneity of the putative reduction of Atlantic surface-ocean circulation and furthermore, with multiproxy synthesis, correlation analysis, and model-data comparison, we document linkages between changes in Atlantic surface-circulation and Western Hemisphere hydroclimate anomalies. Our findings reveal that regardless of whether changes in the AMOC and deepwater formation occurred or not, weakened surface-circulation prevailed in the northern Atlantic basin during the Little Ice Age and was concomitant with widespread and well-documented precipitation anomalies over the adjacent continents.

Figure 2. Garrison Basin multicore reconstructions and corresponding stacked records. Individual core Mg/Ca (mmol/mol) and δ18Oc data (‰, VPDB), and δ18Osw (‰, VSMOW) and SST (°C) reconstructions (blue–MCA, red- MCB, yellow–MCC) plotted with median and 68% uncertainty envelope incorporating age, analytical, calibration, and sampling errors (a-d) along with corresponding median stacked records with 68% and 95% confidence bounds (e-h). Diamonds in a and e indicate stratigraphic points sampled for radiocarbon. Gray histogram in g is the probability distribution for a changepoint in the δ18Osw time series. Orange circle in g is the mean of available δ18Osw measurements in the GOM and orange line in h is observed monthly mean SST with uncertainty envelope calculated using a Monte Carlo procedure that simulates foraminiferal sampling protocol. Purple line in h is the 100-year running correlation between SST and δ18Osw with corresponding uncertainty with shaded boxes indicating correlations with r > 0.7 (p < 0.001), which is the basis for identifying time periods where Loop Current and associated processes are relevant.

Loop Current control on regional SST and SSS variability

We analyzed long-term (~multidecadal) observations in instrumental datasets to place our reconstructions into a global climatic context. The HadISST data set22 documents 0.4–0.7 °C of multidecadal SST variability in the northern GOM over the last century. On these multidecadal timescales, SSTs in the northern GOM correlate highly with SST in the Loop Current region. In particular, long-term SST variability here is impacted by the Loop Current through its eddy shedding processes which are coupled to the strength of transport from the Yucatan Straits through the Florida Straits: if Loop Current transport is anomalously low, then northern GOM SSTs are anomalously cooler due to decreased eddy penetration and the opposite is the case when Loop Current transport is anomalously higher, i.e., northern GOM experiences anomalously warmer conditions. Furthermore, the Loop Current, sitting upstream of where the Gulf Stream originates, correlates highly with SST associated with regions encompassing downstream currents.

In summary, correlation analysis using SSS datasets provides a blueprint for investigating circulation variability and transport into the North Atlantic Ocean.

We also examine long-term correlations between SSS in the northern GOM and mean annual rainfall in the continents adjacent to the Atlantic Basin using rain-gauge precipitation datasets (Fig. 1). Most notably, GOM SSS is anticorrelated with southern North American rainfall (i.e., fresher GOM with wetter southern North America) and is positively correlated with rainfall in West Africa, northern South America, and the southeast United States (|r| > 0.6, p < 0.01). These inferences demonstrate a correspondence between Western Hemisphere hydroclimate and Atlantic Ocean circulation on multidecadal timescales.

Approach to understanding past circulation and hydroclimate

Taken together, we interpret past periods in the Garrison Basin reconstructions when both SST and δ18Osw variability were positively correlated (salty/warm or fresh/cool) as periods during which Loop Current strength fluctuated. We hypothesize that during these periods, increased Loop Current penetration led to increased SST as well as increased advection of more enriched δ18Osw (or more saline waters) into the northern GOM. Using the correlation analysis as a blueprint28, we can pinpoint whether these past fluctuations in the northern GOM δ18Osw record (such as during the LIA) were concomitant with changes in pan-Atlantic SSS records that would implicate circulation changes in the northern Atlantic Ocean. Finally, the long-term correlations with precipitation allow us to contextualize periods where surface-ocean circulation and continental rainfall anomalies were linked, which can then be placed within a multiproxy framework.

In comparing available reconstructions of precipitation during the LIA with our correlation map (Fig. 1), we find remarkable agreement with the proxy record: tree-ring-based PDSI reconstructions in southern North America, and stalagmites from southern Mexico43 and Peru44 capture a wetter LIA compared to modern times whereas a lake record from southern Ghana, titanium percent in Cariaco Basin sediments, and reconstructed PDSI in the southeast U. S. indicate dry LIA conditions. Additional proxy records appear to corroborate this observation as well (brown and green squares in Fig. 1; Supplementary Table 1). These mean state changes during the LIA all appear to be coeval with an anomalously fresher northern Atlantic Ocean, indicative of weakened Gulf Stream strength and reduced surface-ocean circulation.

Figure 5. Simulated correlations between sea-surface salinity and rainfall over last millennium. Correlation map between northern Gulf of Mexico SSS (dashed red box) and global oceanic SSS (red-blue scale) as well as continental precipitation (brown-green scale) from the MPI-ESM transient simulation of the last millennium along with locations of proxy records used in the study. Proxy markers are filled as in Fig. 1. Correlations were performed with 50–150 year bandpass filters to isolate centennial scale variability, where black stippling indicates significance at the 5% confidence level

The transient simulation indicates that a weaker gyre, increased sea-ice cover, and reduced interhemispheric heat transport causes the ITCZ to shift southward and produces anomalous rainfall over the Americas.

This state of weakened AMOC, observed in millennial-scale and glacial paleo-studies, with cool and fresh north Atlantic anomalies and a southward ITCZ, can induce increased rainfall over the southwest US via atmospheric teleconnections associated with the North Atlantic subtropical high overlying the gyre. Despite this southward shift, positive SSS anomalies can occur in the tropical Atlantic (and negative anomalies in the northern Atlantic) due to reduced freshwater input resulting from decreased rainfall in the Amazon and West African regions. Eventually, the tropical positive salinity anomaly in the southern Atlantic propagates northward, thereby strengthening meridional oceanic transport and providing the delayed negative feedback.

Though the length of the instrumental record limits us from directly analyzing centennial-scale correlations, there is theoretical and modeling evidence to implicate similar ocean-atmosphere processes on multidecadal and centennial timescales. Both model and observational analyses reveal a dipolar structure in Atlantic Ocean SSS that is consistent with the LIA proxies and thereby supports our hypothesis linking meridional salt transport and tropical rainfall. Both analyses also display similarities in continental precipitation patterns over western Africa, northern South America, and the southwestern United States, which are also consistent with the LIA hydroclimate proxies.

Summary

The broad agreement between the analyses supports similar ocean-atmosphere processes on multidecadal-to-centennial timescales, and provides additional evidence of a robust century-scale link between circulation changes in the Atlantic basin and precipitation in the adjacent continents.

Regardless of the specific physical mechanism concerning the onset of the LIA, and whether AMOC changes were linked with circulation changes in the surface ocean, we hypothesize that the reported oscillatory feedback on centennial-time scales involving the surface-circulation in the Atlantic Ocean and Western Hemisphere hydroclimate played an important role in last millennium climate variability and perhaps, over the late Holocene.

 

 

 

 

 

 

 

Professional hydrologist Rob Ellison has for years been thinking and writing to connect the dots between the sun, ocean and climate. Recently he wrote this post at his excellent blog Terra et Aqua, An Earnest Discovery of Climate Causality (link in red)

Below I provide some excerpts from his discussion about an ocean mechanism which would be much better understood, were it not for the CO2 obsession sucking up most of the research funding.

Overview

It is hypothesized that upwelling in the Pacific Ocean is modulated by solar activity over periods of decades to millennia – with profound impacts on communities and ecosystems globally. The great resonant systems of the Pacific respond at variable periods – the tempo increased last century for instance – of La Niña and El Niño alternation. . .The mechanism proposed is a spinning up of the Pacific gyres as a result of colder and denser polar air. Low solar activity spins up the gyres producing more frequent La Niña (more equatorial upwelling) – and vice versa.

Pacific Oscillations Global Impact

The Pacific has a globally influential role in climate variability at scales of months to millennia. The variability in atmospheric temperature, rainfall and biology has its origin in the volume of cold water rising off California and in the equatorial Pacific. It is an ever changing anomaly.

The principle of atmospheric heating and cooling by ENSO is very simple. Cold, nutrient rich currents cascade through the deep oceans over a millennia or more. These turbulent currents don’t generally emerge through a sun warmed surface layer. By far the most significant deep ocean upwelling is in the eastern and central Pacific. Cold water in contact with the atmosphere absorbs heat and warms as the atmosphere cools. At times there is less upwelling and warm water spreads eastward across the Pacific – warming the atmosphere. It is simple enough to see in temperature data.

I have a preference for near global coverage and depth integrated satellite temperature records – it doesn’t miss energy in latent heat at the surface for one thing. 21st century instrumentation is much to be preferred going forward. Over the past century the 20 to 30 year influence of the Pacific Decadal Oscillation (PDO) anomaly can be seen in the surface records. Warming to the mid 1940’s, cooling to 1976, warming to 1998 and little change since. The PDO and ENSO are, moreover, in lockstep. A cooler PDO anomaly and more frequent and intense La Niña – and vice versa.

Pacific Gyres Spinning Up Climate Change

The atmospheric/ocean system of triggers and feedbacks varies – usually abruptly with triggers. The trigger for more upwelling I can only imagine is the great ocean gyres. Ocean gyres spin up on the surface through winds and planetary rotation. Pressure systems shift polar winds and storms into lower latitudes. High polar atmospheric pressures spin up the gyres pushing cold polar water into the Californian and Peruvian currents. Roiling cold water upwelling sets up wind and current feedback across the Pacific.

More polar cold water at the surface facilitates upwelling in critical regions.  Trade winds spin up as a feedback and piles warm water against Australia and Indonesia.  Sometimes the winds falter and warm water flows back eastward suppressing cold upwelling.  The whole is a complex and dynamic system triggered by changes in atmospheric pressure zones in the north and south Pacific.  Great movements of atmospheric mass driven by a marginal change in solar activity.  A large reaction from a small jolt as expected with technically chaotic systems.

Tessa Vance and colleagues from the Antarctic Climate and Ecosystems CRC found a proxy of eastern Pacific upwelling in an ice core at the Law Dome Antarctica.  A higher salt content – from polar westerlies – is a proxy for solar activity.  But also results in changes in the great Pacific gyres and the intensity of upwelling.   More upwelling brings rain and cyclones to Indonesia and northern and eastern Australia, drought in the United States of and South America, cooler global temperatures and biological abundance.   Less in El Niña conditions and we – in Australia – get drought.   The absolute volume of rainfall is roughly constant but where it falls on the planet changes.

The record captures in high resolution the 20 to 30 year Pacific beat, the change in the ENSO tempo last century and has at least a resemblance to the solar signal over a 1000 years.  But even with a millennial high El Niño anomaly last century – conditions have been far more extreme at other times in the past 12,000 years.

Conclusion

Will there be more La Niña over the next centuries? Can we expect more El Niño in a thousand years?  Might we see great herds return to the Sahel?  The future remains unpredictable.   Still – a return to the mean scenario does suggest better odds on a cooler sun and a little more upwelling in the Pacific Ocean – a cooling influence on the atmosphere and the inevitable regional variabilities in rainfall.

Oceans Make Climate is a major theme at this blog, since I fortunately made the acquaintance of Dr. Arnd Bernaerts.  Rob Ellison adds another important dimension with his consideration of the gyres.

Footnote:

Recently I noticed how sea surface temperatures drove the 2015-2016 global warming, as shown in the HadSST3 record:

Note that higher temps in 2015 and 2016 are first of all due to a sharp rise in Tropical SST, beginning in March 2015, peaking in January 2016, and steadily declining back to its beginning level. Secondly, the Northern Hemisphere added two bumps on the shoulders of Tropical warming, with peaks in August of each year. Finally, note that the global release of heat was not dramatic, due to the Southern Hemisphere offsetting the Northern one.

Much ado will be made of this warming, including claims of human causation, despite the obvious oceanic origin. Further, it is curious that CO2 functions as a warming agent so unevenly around the world, and that the Tropics drove this event, contradicting CO2 warming theory.

Anatomy of the Hottest Years Ever

 

Internal Climate Variability Trumps Global Warming (here) is a
great post by hydrologist Rob Ellison confirming how the Oceans Make Climate. He was intrigued by discovering that rivers in eastern Australia changed form – from low energy meandering to high energy braided forms and back – every few decades. For almost 30 years he looked for the source and import of this variability, and has found it in the ocean.

Turns out that it is a combination of conditions in the northern and central Pacific Ocean that is of immense significance. A 20 to 30 year change in the volume of frigid and nutrient rich water upwelling from the abysmal depths. A generally warmer or cooler sea surface in the northern Pacific and greater frequency and intensity of El Niño or La Niña respectively. This sets up changes in patterns of wind, currents and cloud that cause changes in rainfall, biology and temperature globally. In the cool pattern shown above – booming ecologies, drought in the Americas and Europe, rainfall in Australia, Indonesia, Africa, China and India and cooler global temperatures. The reverse in the warm phase. Warming to 1944, cooling to 1976, warming again to 1998 and – at the least – not warming since. It leads to a prediction that the La Niña currently emerging is likely to be large.

A Persistent Ocean Cycle

Changes in the Pacific Ocean state can be traced in sediment, ice cores, stalagmites and corals. A record covering the last 12,000 years was developed by Christopher Moy and colleagues from measurements of red sediment in a South American lake. More red sediment is associated with El Niño. The record shows periods of high and low El Niño activity alternating with a period of about 2,000 years. There was a shift from La Niña dominance to El Niño dominance 5000 years ago that is associated with the drying of the Sahel. There is a period around 3,500 years ago of high El Niño activity associated with the demise of the Minoan civilisation (Tsonis et al, 2010).

Tessa Vance and colleagues devised a 1000 year record from salt content in an Antarctic ice core. More salt is La Niña as a result of changing winds in the Southern Ocean. It revealed several interesting facts. The persistence of the 20 to 30 year pattern. A change in the period of oscillation between El Niño and La Niña states at the end of the 19th century. A 1000 year peak in El Niño frequency and intensity in the 20th century which resulted in uncharacteristically dry condition since 1920.

Conclusion

The whole post is worth reading and a solid contribution to our understanding. Ellison’s summary is pertinent, compelling and wise.

It is quite impossible to quantify natural and anthropogenic warming in the 20th century.  The assumption that it was all anthropogenic is quite wrong.  The early century warming was mostly natural – as was at least some of the late century warming.  It seems quite likely that a natural cooling with declining solar activity – amplified through Pacific Ocean states – will counteract rather than add to future greenhouse gas warming.   A return to the more common condition of La Niña dominance – and enhanced rainfall in northern and eastern Australia – seems more likely than not.

I predict – on the balance of probabilities – cooler conditions in this century.  But I would still argue for returning carbon to agricultural soils, restoring ecosystems and research on and development of cheap and abundant energy supplies.  The former to enhance productivity in a hungry world, increase soil water holding capacity, improve drought resilience, mitigate flooding and conserve biodiversity.  We may in this way sequester all greenhouse gas emissions for 20 to 30 years.  The latter as a basis for desperately needed economic growth.  Climate change seems very much an unnecessary consideration and tales of climate doom – based on wrong science and unfortunate policy ambitions – a diversion from practical and measured development policy.