Climate Links: Resilient Arctic & Pacific Decadal Oscillation

Items that caught my eye this morning on Twitter:

“Scientists: Arctic Is More Resilient To Global Warming Than We Thought” Who is “We” and why did “we” think the Arctic wasn’t resilient?  The second is easier to answer: because climate scientists with bullhorns told us for years that the Arctic was “DOOMED!”  I’ve written about this topic and knew when the record low extent and volume occurred in 2012 that it was likely one bad year and not the end of the world.  I haven’t seen or heard from those same scientists who breathlessly told the public about the doomed Arctic in 2012 that they were wrong (boy, were they wrong!).  While this article makes that point today (3 years too late), I don’t expect anyone to remember it when the Arctic has another bad summer.  2013 was a good Arctic summer: cooler than recent years – and guess what? Arctic ice responded by … growing – you know, what it’s supposed to do according to physics.  Headslap.

“To truly grasp what we’re doing to the planet, you need to understand this gigantic measurement”  This is an article about “giga”: what the prefix means and how people should know about it.  I disagree with it from the perspective that the explanations don’t utilize anything truly useful.  For example: a gigaton is “more than 6 million blue whales”.  Who knows how much a big whale weighs?  Can you envision 6 million of them?  The basic problem with giga is it is so big that it defies our everyday experiences.  The superficial problem is despite being written by someone who understands science, the article likely misses its intended audience and thus is not useful.

At the risk of delving too far into technical issues, this article is useful for me personally based on relevance to my geographic region’s upcoming winter weather: “Subtle Differences to Previous El Niños Key to Winter Forecast, And Why the PDO Matters“.  The PDO is the Pacific Decadal Oscillation – a low-frequency natural climate pattern that has direct and indirect influences on weather across at least the western half of the nation.  Many people in my professional community are aware that there is currently a strong El Nino in the equatorial Pacific.  I noted from recent write-ups that there are also warm sea surface temperature anomalies in the north Pacific (e.g., off the west coast of the U.S.) – in addition to the warm anomalies across the central and eastern equatorial Pacific (hallmarks of El Ninos).

The northern Pacific anomalies are an oddity and this article helps explain why they might be present.  In the late 1990s, the PDO likely entered into a cool pattern, which helps explain a couple of things.  First, El Ninos during the 2000s and 2010s had lower amplitude (cooler).  And second, global temperatures didn’t rise as quickly since 1998 as they did during the previous PDO phase (1977-1998).  This observation is also known as the global warming “hiatus” or “pause”.  A cool PDO means Pacific sea surface temperatures are cooler than average.  One effect of this is the Pacific absorbs heat from the atmosphere and keeps the atmosphere cooler than it otherwise would be.  The opposite is also true: warmer than average Pacific SSTs releases more heat to the atmosphere than is absorbed and the atmosphere warms more than average.

Which leads me to the next article: “Has the PDO Flipped to a Warming Phase?”  The PDO typically stays in a warm or cool regime for 10 to 30 years – hence the “multidecadal” characterization.  As I wrote above, the PDO moved into a cool phase in the late 1990s.  Recent positive temperature anomalies (since 2014) might indicate that the PDO is temporarily positive or it might indicate the PDO switched back to a positive or warm phase.  This has significant implications for global weather patterns until it switches back to its negative phase.  For example, I wrote above that there is currently a strong El Nino.  If the PDO switched to a positive phase, it could enhance any El Nino.  It would also do what I described above: release heat back into the atmosphere.  This means the global warming “hiatus” is, if the PDO switches, over.

Back to the Colorado forecast.  With a warmer north and equatorial Pacific (positive PDO and ENSO), what kind of winter can we expect?  The answer won’t surprise you: it’s hard to tell.  There are few similar historical examples that scientists can use to issue a reliable forecast.  They have to determine if warmer ocean temperatures persist and how the atmosphere’s jet stream responds.  Ridge and trough locations over the western US will ultimately determine when we get snow and how much snow we get during each storm.

Commercialized Carbon Removal

The Guardian has an interesting article about startups working on capturing carbon dioxide from the air – a necessary technology if we are serious about any kind of climate goal with less CO2 than our business-as-usual pathway.  What are the companies doing and why is it important?  The article highlights three businesses: Carbon Engineering, Global Thermostat and Climeworks, which started in the 2000’s.  “All are aiming to make low-carbon fuels, used recycled CO2 and renewable energy to power the process.”  They’re making low-carbon fuels because small markets for them already exist.  Those markets will have to increase in size and scope for these startups to grow.

That’s one important aspect.  Another is the so-called “climate goal”.  As stated by international groups and increasing numbers of scientists, the climate goal is keeping CO2 concentrations below a certain threshold in order to keep global temperatures from increasing above 2C.  There is another international climate conference scheduled for later this year – the Conference of Parties in Paris, France (COP-21).  Leading up to that conference, countries are submitting carbon reduction goals that can be internationally monitored and verified.  Goals stated so far will definitely not meet the <2C goal – read about the UK’s goals here, for example, or here about the 45 countries who submitted plans already.  The reason is simple: we cannot deploy enough renewable energy generation or institute enough efficiency measures or change fuel types fast enough that will translate into halving global CO2 emissions within 10 years and going net negative by 2050.

What these companies are doing is directly related to that last goal: net negative CO2 emissions.  It won’t happen by 2050 or any other year unless we push serious money into research, development, and deployment.  It will take the private and public sectors working together for decades for utility-scale CO2 withdrawal from fuel burning and the free atmosphere.  These companies, and others, are the forefront of that industry.  But they need capital – a lot of it.  Cashflow at this juncture of their existence is crucial for them to exist long enough to deploy their technologies and evolve them as they run in the real world.  Anyone have a spare million or so dollars sitting around?

Water efficiency

I saw a tweet last night that I found interesting.

To those who say water-use efficiency can’t save much #water, it’s the only thing that can. http://t.co/g1OeYMUsr3 pic.twitter.com/1y52YhuTp3

— Peter Gleick (@PeterGleick) July 9, 2015

“The only thing that can.”  I hope Peter means water-use efficiency for all users.  The graphic he includes with this tweet suggests he’s focused on household toilet usage in California.  I’ll round the numbers used in the graphic: 1980 usage was 800,000 acre-feet per year; current use (no efficiency) is 1,200,000 acre-feet per year.  Current savings from efficiency improvements: 640,000 acre-feet per year.  Additional potential savings: 290,000 acre-feet per year.

The 640,000 AFY is laudable.  That’s a lot of water that Californians don’t have to use and thankfully aren’t.  That is a real accomplishment.  An additional 290,000 AFY is a good goal to work on – why waste a resource when you don’t have to.

But toilet water usage isn’t the primary usage of California water – and it’s that small point that troubled me when I saw the tweet.  Total water usage in California is 40,00,000 AFY.  That 640,000 efficiency represents just 1.6% of the total usage.  It also represents >50% reduction from what water usage could be without any efficiency measures.  What I want to know is what efficiencies water-thirsty California agriculture implements.  Agriculture is by far the dominant user of water – if we achieved just 1% sector efficiency, how much more water could California save because of the scale of industry usage compared to residential usage?

Agriculture is a sizable part of the California economy – $43 billion industry that generates $100 billion in overall economic activity.  Because of that, agriculture wields political clout in Sacramento.  This means that while physical scientists can inform policymakers on the ongoing drought, we need the social sciences to inform policymakers how to deal with it.  I would also like to see quantitative results of efficiency gains by sector.

Climate Papers

I found this article from a Tweet this morning:
Prof John Mitchell: How a 1967 study greatly influenced climate change science

The Carbon Brief blog asked climate scientists to nominate the most influential refereed paper.  Manabe & Wetherland’s 1967 paper entitled, “Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity” was the winner.  The paper incorporated the transfer of heat from the Earth’s surface to the atmosphere and back for the first time in a model.  Their model produced surface temperatures that were closer to reality than previous efforts.  They also tested constant and doubled atmospheric CO2 and found global mean temperatures increased by 2.4C under a doubling scenario.  In a nutshell, a simple model in 1967 projected the same warming signal as dozens of more sophisticated models do today.

I am not the first to pose the following question: what additional value do today’s extensive models provide over simple models?  Climate scientists still use simple models in their investigations.  They’re obviously useful.  But posing the question differently addresses my more recent interests: does the public derive more value from today’s climate model results than they did before with simpler and cheaper models?  The most obvious addition to me is the increasing ability to resolve regional climate change which is more variable than the global mean.  I do wonder how the public would react if they heard that climate models are largely generating the same projections given the amount of money invested in their development and analysis.  We have a partial answer already with the growth of climate skeptics in the public sphere.  Some people are obviously drawn to the problem.  As complex as all the aspects of the problem are and as busy as most people are, perhaps it is in science’s best interest to not make too much noise.

I will also note that one of the drawbacks of climate science in the academy is the utter lack of historical context for results.  My experience really has been the proverbial information dump as part of the information deficit model of learning.  The Facts Speak For Themselves.  I don’t remember hearing about this article that so many in my field consider seminal.  My colleagues would benefit from exposure to the history of their science.