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Over the tipping point

Posted on 6 July 2011 by steve.oconnor

A debate is taking place in a small specialised section of the scientific community that has profound implications for the planet's climate, but you won't hear it mentioned in Parliament any time soon.

The argument is about the Arctic sea-ice and its precipitous decline over the past couple of decades. Those who are up to speed on the issue recognise that the poles are the coalface for climate change, heating up faster than anywhere else on Earth.

Although the polar ice-sheet is thin - in some places less than 1m - it acts like a giant mirror, reflecting the sun and keeping the region cool. Once it’s gone, the dark ocean will heat up faster, accelerating the effects of climate change. If the poles are the coalface, then the Arctic sea-ice is its canary.

Until recently, the conventional wisdom was that once the sea-ice disappears in summer - possibly as early as 2030 - it stays gone, but a study came out recently challenging that view. It concluded that the ice may come and go in somewhat dramatic fits and starts, until it eventually peters out in the second half of this century.

In other words, whichever way you look at it, the canary is dying.

The director of the National Snow and Ice Data Centre, Mark Serreze, and his team have studied the Arctic for over 20 years. He explains: “We’re now committed to an ice-free Arctic in the summer – there’s just too much carbon dioxide in the atmosphere and the planet’s getting too warm. We’ve crossed a tipping point.”

The trouble is, we've really got no idea if (or when) this will automatically trigger other tipping points or feedback mechanisms that could lead to runaway warming. This may take many forms, from shifting ocean currents destabilising vast methane deposits to natural carbon sinks flipping to become sources. Computer models just aren't good enough to tell.

What is known, however, is that natural global warming periods during the Earth's deep past have been severe enough to cause hurricanes with so much force they've left permanent scars on the ocean floor. During these times, the planet shifted to an unstable state where small initial warmings were amplified by only partially-known mechanisms. Some of these episodes were so violent they came close to extinguishing life completely.

We may think we're clever enough to hedge our bets on how much carbon dioxide we can keep pouring into the atmosphere, but just take one look at the recent global financial crisis and ask ourselves, “Are we ready to risk our lives on predictions from a handful of computer simulations?”

Here in Australia, half a world away from the Arctic, the Government will shortly unveil a plan on how we can reduce emissions. It’s a good first step, but it won't be nearly enough by itself.

Beyond Zero Emissions and the University of Melbourne Energy Institute  have teamed up to write a courageous plan to transform our energy sector and propel it into the 21st Century.

The plan, which has wind and solar thermal power at its heart, weans us off fossil fuels within just 10 years, with a cost of about $8 a week for households.

Concentrating solar thermal with molten salt storage can yield baseload power even when the sun isn’t shining. Unlike so-called clean coal, which promised much yet delivered little, it is already a proven technology. Unlike nuclear, it doesn't need long-term plans for disposing radioactive waste and decomissioning obsolete plants. Not only will large-scale solar create thousands of jobs, it will revitalise a flagging industrial sector. It may even jolt other countries into action, lest they be left behind.
Building a renewable energy system will require investments in grid upgrades and specific policies to drive deployment such as a national large-scale feed-in tariff. But more than that, it will need courage and leadership from all sides of politics.

As cyclone Yasi and the floods earlier this year have reminded us yet again, the weather is intensifying. Even if we stopped all emissions immediately, the incredible momentum of the climate makes it likely that the worst is still yet to come. Regarding the Arctic tipping point, Serreze adds: "What I find sobering is that the science has moved beyond accepting the inevitability of a seasonally ice-free Arctic Ocean to only questioning the finer points of how we're going to get there."

Even the most hardened skeptic should surely feel a shiver down their spine at the research collaboration underway in the bowels of three British universities. They’re designing a type of pipe, up to 25km in length with one end to be suspended high into the atmosphere using balloons. If taken to production, sulphur aerosols will be injected directly into the stratosphere via these pipes in a desperate attempt to cool the planet. Although vastly cheaper than fixing the real problem, once we start geo-engineering the climate there will be no turning back: we will be condemning future generations to a dystopian nightmare.

Perhaps instead we should take a long, deep breath and think about what’s really important to us. Not just as a society, but as human beings and as part of a wider web of life on this planet. As Beyond Zero Emissions have demonstrated so brilliantly, if we act now - even in the face of huge uncertainty - we could have a chance at turning things around. Then at least we might have one heck of a story to tell our grandchildren.

Now what kind of price would that be worth paying?

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Comments 1 to 16:

  1. I wish Beyond Zero Emissions were realistic - but it isn't, as this critique shows. beyond zero critique Wishful thinking won't solve our problems. We need to confront the realities of renewables not (yet) being ready to provide the full answer and focus on what needs to be done to get them there while we put in place bridging solutions. It would be good to see Mark Diesendorf's plans Baseload renewable plan put to the test somewhere with a "utility" that uses a mix of wind (with intelligent predictive anemometering) and solar thermal supported by gas/biofuel turbines (or similar) to manage the variability Or perhaps there are other variations on this theme? A plan to make a relatively modest investment as a sort of "demonstrator" seems smarter to me than trying to push a whole of industry transformation plan that lacks credibility and won't get support because of entrenched interests and easily attacked heroic assumptions. We need to put up proposals that acknowledge we don't know all the answers and need to find out rather than grand schemes that purport to "fix" the problem.
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  2. I delved into the comments over at The Drum... and now my head hurts! Comments about how arctic ice doesn't affect solar heating during the arctic winter; equating "models have uncertainty" with "models are completely wrong"; and the best one of all, quoting WUWT as an authoritative source of scientific information! That one also linked a graphic showing total global sea ice area, claiming it doesn't show any decrease. I tried to post a comment that the graphic in fact clearly shows a decline of at least 2 million km2 over just the last 30 years, which is an area as large as NSW, Victoria, and Sth Australia put together, but that hasn't made it through the ABC moderators yet.
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  3. Zero emissions will always be impossible. Wind turbines are not zero carbon systems, they are very low carbon systems, as are most renewables and sustainable systems. Production, maintenance and decommissioning of the systems will have a small carbon footprint. We can ultimately only do our best and reduce greenhouse gas emissions to the lowest possible.
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  4. Mark, I live in a place that would be perfect for such a test--Hawaii county. We have a relatively small population (185,000) with ample geothermal, solar and wind resources. Yet the vast majority of our electricity is produced from oil. It drives me crazy that this island is not self-sufficient in electrical production. The power utility thinks they are being radical by trying to produce 30% from non oil sources by 2020. Jerry
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  5. Paul D I agree that zero emissions will always be impossible. However I don't think that zero net emissions is out of reach. It's perfectly sensible for people to complain, at the moment, that carbon offsets with tree planting schemes and the like are little more than greenwashing. However, if emissions were only the truly unavoidable ones - say liquid fuels for (some) air travel and other specialty applications, it would be pretty easy to work out the size of the block of olivine (or similar rock) you need to buy for crushing to ensure near instant absorption by weathering of the equivalent amount of airborne CO2. So a little bit of appropriate geoengineering - speeding up absorption of CO2 to exactly match the accelerated release of CO2 - would be manageable. Viola! Zero net emissions.
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  6. @Jerry #4 Perhaps then you need to lobby the relevant pollies in Hawaii who want a highly visible electoral platform to get in touch with Mark Diesendorf and see if they will adopt such a program? I've no idea what the generation cost base is in Hawaii but I can see that it would, on the face of it, be a natural place as you say for geo-thermal, solar and wind. It would also seem to be highly vulnerable to a break in oil supply? Is the power utility there private or government? Who knows - Hawaii could be a great showcase for a renewables experiment? :)
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  7. Considering it is the total amount of CO2 that is put in to the atmosphere that counts for global warming outcome and taking the precaution of wanting a 95% chance of keeping to ~2C (that is at most 350ppm by 2100) then isn't zero emissions just the starting point and aren't all the CO2 used to employ any new energy system CO2 that will have to be re-removed from the atmosphere again? To be safe from latest predictions means 350ppm asap and that means a massive carbon sequestration effort or many years of human activity resulting in carbon sequestration or negative carbon emissions. Peak 400ppm, that means 20% reductions in emissions to 2017 and carbon sequestration is necessary to get to 350ppm by 2100 and that is being optimistic about the carbon cycle! This is never going to happen of course as it means the west would have simplify its lifestyle, so what does unsafe CC mean and will it matter how many renewables there are?
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  8. The PIOMAS ice volume model results were recently updated through the end of June and now show an anomaly of about -9800 km^3... breaking the previous record low anomaly set last year by about 600 km^3. If volume loss from now through September followed the long term average, such that the anomaly remained -9800 km^3, that'd result in a September monthly average of just 2500 km^3... well below even last year's (record low) one day minimum of 4400 k^3. To me this suggests that the sharply falling volume trend of the past five years or so has not been 'just an anomaly' or 'caused by export of thick ice'. Rather, it suggests that alot of the volume loss has been due to ice melting in situ due to warmer ocean waters... which if correct would mean that the trend should only continue to accelerate (rather than reversing if it was a statistical anomaly or leveling off if it was due to export of thick ice which no longer exists). This would also suggest that 'the ice stays gone' view is more likely correct than the 'comes and goes' idea from Amstrup's 2010 study in Nature. Interestingly, while the volume is currently about 3300 km^3 lower than at the same point in 2007 the ice extents are nearly identical. This demonstrates how great the disconnect between the two measurements can be. That said, zero volume perforce means zero extent... so as we get closer to zero volume we should start to see extent dropping dramatically.
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  9. Wonder what weather changes the rapid loss of arctic summer ice will bring?
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  10. @3. Paul D "Wind turbines are not zero carbon systems, they are very low carbon systems, as are most renewables and sustainable systems." Paul, the necessity to burn FF to produce any form of alternative power is an initial cost only. Once we get to the point where a substantial fraction of our energy comes from alternative sources, the clean energy they generate will make a substantial contribution to the manufacture of any further windmills etc. Therefore, clean energy will get to the point where it will produce more clean energy while reducing and soon replacing all FF.
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  11. @villabolo: don't forget CO2 emissions from concrete and steel manufacture also. Certainly they're a relatively small part, compared to the electricity generation. And they'd certainly be manageable. There are even alternatives for steel - e.g. direct reduced iron instead of coke-fired blast furnaces. Either way, a wind turbine produced using the dirtiest of brown-coal-fired electricity is *still* one of the lowest-carbon sources of electricity we have available to us. It's certainly an awful lot better than continuing to burn that brown coal...
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  12. Ranyl wrote: "Wonder what weather changes the rapid loss of arctic summer ice will bring?" Yeah, that's the looming question. The problem is, as the article notes, it is just such a huge change that we can't tell what will happen. Will the removal of the sea ice allow a strong Pacific to Atlantic current to develop through the Arctic ocean? Will that change the course of the Gulf Stream and thus replace warm North Atlantic waters pulled up from the equator with frigid waters pulled down from the North Pole? Will the albedo shift be enough to warm Arctic waters to the point that clathrates release large amounts of methane into the atmosphere? What will all these changes do to the melt rate of the Greenland ice cap? And if the weather has been on a crazy roller-coaster ride for the past couple of decades what will a fundamental change to the planet's climate system provoke? The whole world is about to get a first hand demonstration of why the saying, 'May you live in interesting times', is considered a curse.
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  13. Adelady #5: A CO2-balancing scheme may have worked in a pre-350 ppm world. However, our present situation is far worse because there are now more sources of CO2 (soil aeration, deforestation, permafrost, methane clathrates, etc...) than those caused by human burning of fossil fuels. In other words, EVEN if human emissions when to zero NOW, the Earth is still probably headed to 1200 ppm CO2 within 200 years. Maybe 800 ppm by 2100. We are in a deep hole, but still digging. Have you seen the video where a cruise ship Captain tries to avoid crashing into a dock, but can't stop the momentum of the ship? Well, imagine you are a passenger on that ship, and the only means you have to avert the crash is to move the Ocean! Because that is the equivalent task for the Public in averting Climate Change... As we capture CO2, the world Ocean simply gives up its sink of dissolved CO2 to maintain gas pressure equilibrium between the ocean and atmosphere. This is why Climate Change is unstoppable for millennia. The only reasonable solution is restoring the biosphere, and letting time take it's course. Do we have the wisdom and courage to take this action? Or will the Captains of Industry pilot Human Civilization onto the rocks? Remember who took the lifeboat seats on the Titanic...
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  14. Artful Dodger @13, currently the annual increase in atmospheric CO2 is still less than annual human CO2 emissions. Therefore natural sources are still a net sink of CO2, and where we to stop all CO2 emissions tomorrow, the CO2 concentration in the atmosphere would start to slowly decrease. It is true that evidence is showing the natural carbon cycle is becoming less efficient as a sink for anthropogenic CO2. Further, it is true that we may be approaching one of several potential tipping points that would turn natural sources into a net source of CO2. Indeed, warming currently in the pipeline due to thermal lag may even take us over such a tipping point. Consequently it is possible that natural processes could take us to 1200 ppm CO2 by 2200, but it is not likely. In the event that we stopped all emissions in the next 10 or even 20 years, it is more likely than not that CO2 concentrations would decrease. But the longer we delay, the more likely that natural mechanisms will double or even triple CO2 concentrations.
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  15. #13, Artful Dodger, I answered that question in another thread /argument.php?p=2&t=113&&a=80#54888 and a link to a simple spreadsheet. There was general agreement that if we stopped now, the current level would fall half way back to preindustrial within 50 years.
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    Moderator Response:

    (DB) Umm, no, there was not "general agreement"; please re-read the responses and look for mine and Sphaerica's comments (the guest post by Dr Franszen has discussion supporting Dodger's position on oceanic outgassing of CO2).


    [DB] The post I referenced is the Seawater Equilibria thread.  The relevant discussion I alluded to starts at comment 30.  Specific relevant comments are numbers 33, 41, 43, 45, 67, 78 and 81.

  16. Joe Romm posted on this today: Climate Change Reducing Ocean’s Carbon Dioxide Uptake
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