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February 2013 CO2 Concentrations: 396.80 ppm

During February 2013, the Scripps Institution of Oceanography measured an average of 396.80ppm CO2 concentration at their Mauna Loa, Hawai’i’s Observatory.

This value is a big deal.  Why?  Because not only is 396.80 ppm the largest CO2 concentration value for any February in recorded history, it is the largest CO2 concentration value in any month in recorded history.  More on that below.  This year’s February value is 3.37 ppm higher than February 2012′s!  Most month-to-month differences are between 1 and 2 ppm.  This jump of 3.37 ppm is very high.  Of course, the unending trend toward higher concentrations with time, no matter the month or specific year-over-year value, as seen in the graphs below, is more significant.

Let’s get back to that all-time high concentration value.  The yearly maximum monthly value normally occurs during May. Last year was no different: the 396.78ppm concentration in May 2012 was the highest value reported last year and, prior to this moth, in recorded history (neglecting proxy data).  We can expect March, April, and May of this year to produce new record values.  I wrote the following last month:

If we extrapolate last year’s maximum value out in time, it will only be 2 years until Scripps reports 400ppm average concentration for a singular month (likely May 2014; I expect May 2013′s value will be ~398ppm).  Note that I previously wrote that this wouldn’t occur until 2015 – this means CO2 concentrations are another climate variable that is increasing faster than experts predicted just a short couple of years ago.

For the most part, I stand by that prediction.  But actual concentration increases might prove  me wrong.  Here is why: the difference in CO2 concentration values between May 2012 and February 2012 was 3.13 ppm (396.78 – 393.65).  If we do the simplest thing and add that same difference to February’s value, we get 399.93 ppm.  That is awfully close to 400 ppm.  A more robust approach would be to add an average value – say the annual growth rate from the past 3, 5, or 10 years.  Over those time periods, the average differences are 2.31 ppm, 2.08 ppm, and 2.08 ppm.  So it’s probably safe to assume a growth of at least 2 ppm, which is what I did in my original prediction.  396.78 ppm + 2 ppm = 398.78 ppm (2013′s prediction).  398.78 ppm + 2 ppm = 400.78 ppm (2014′s prediction).  But if we use annual averages, we smooth out the large jumps in concentration values (like the 2013-2012 February difference).  There are other calculations that we could do to come up with a range of predictions, but I unfortunately don’t have the time to do them right now.  We will have to be content with waiting until early June to find out how fast concentrations are rising this year.

It is worth noting here that stations measured 400ppm CO2 concentration for the first time in the Arctic last year.  The Mauna Loa observations are usually closer to globally averaged values than other sites, such as in the Arctic.  That is why scientists and media reference the Mauna Loa observations most often.

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Figure 1 – Time series of CO2 concentrations measured at Scripp’s Mauna Loa Observatory in February: from 1959 through 2012.

This time series chart shows concentrations for the month of January in the Scripps dataset going back to 1959. As I wrote above, concentrations are persistently and inexorably moving upward.  How do concentration measurements change in calendar years?  The following two graphs demonstrate this.

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Figure 2 – Monthly CO2 concentration values from 2009 through 2013 (NOAA).  Note the yearly minimum observation is now in the past and we are two months removed from the yearly maximum value.  NOAA is likely to measure this year’s maximum value between 398ppm and 399ppm. photo CO2_concentration_50y_trend_NOAA_201303_zpscb598ad2.png

Figure 3 – 50 year time series of CO2 concentrations at Mauna Loa Observatory.  The red curve represents the seasonal cycle based on monthly average values.  The black curve represents the data with the seasonal cycle removed to show the long-term trend.  This graph shows the recent and ongoing increase in CO2 concentrations.  Remember that as a greenhouse gas, CO2 increases the radiative forcing toward the Earth, which eventually increases tropospheric temperatures.

In previous posts on this topic, I show and discuss historical and projected concentrations at this part of the post.  I will skip this for now because there is something about this data that I think provides a different context of the same conversation.  The increase in average annual concentrations in 2012 generated quite a bit of buzz in media outlets this week.  I dismissed the first couple of reports I saw because I’ve spent so much time during the past year writing about the concentrations.  But more media outlets wrote and discussed the same topic as the week went on.  So I think it is a valid story, especially after I saw a graphic that I thought should have been the focus the entire time:

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Figure 4 – CO2 concentration (top) and annual average growth rate (bottom). Source: Guardian

The top part of Figure 4 should look familiar – it’s the black line in Figure 3.  The bottom part is the annual change in CO2 concentrations.  If we fit a line to the data, the line would have a positive slope, which means annual changes are increasing with time.  So CO2 concentrations are increasing at an increasing rate – not a good trend with respect to minimizing future warming.  In the 1960s, concentrations increased at less than 1 ppm/year.  In the 2000s, concentrations increased at 2.07 ppm/year.

The greenhouse effect details how these concentrations will affect future temperatures.  The more GHGs in the atmosphere, all else equal, the more radiative forcing the GHGs cause.  More forcing means warmer temperatures as energy is re-radiated back toward the Earth’s surface.  Conditions higher in the atmosphere affects this relationship, which is what my volcano post addressed.  A number of medium-sized volcanoes injected SO2 into the stratosphere (which is above the troposphere – where we live and our weather occurs).  Those SO2 particles reflect incoming solar radiation.  So while we emitted more GHGs into the troposphere, less radiation entered the troposphere in the past 10 years than the previous 10 years.  With less incoming radiation, the GHGs re-emitted less energy toward the surface of the Earth.  This is likely part of the reason why the global temperature trend leveled off in the 2000s after its run-up in previous decades.

This situation is important for the following reason.  Once the SO2 falls out of the atmosphere, the additional incoming radiation will interact with higher GHG concentrations than was present in the late 1990s.  We will likely see a strong surface temperature response sometime in the future.

In my mind, the newsworthy detail is not that CO2 concentrations increased at the second fastest rate on record in 2012.  In climate, year-to-year differences matter less than long-term trends.  In my mind, the decadal concentration increase is what is noteworthy.  If concentrations rise by an average of >3 ppm/year in the 2010s or 2020s, a great deal of future warming and other climate change effects will occur.

It is my opinion that global temperature rise by 2100 will exceed 2C.  This target is primarily politically-driven.  Scientific research doesn’t exist that dictates 2C is “safe”.  Scientific research does exist that projects the likely temperature response to a range of CO2 concentration values.  If we do want to prevent >2C global temperature rise by 2100, we would have to immediately stop emitting CO2 and begin removing CO2 from the atmosphere.  We currently don’t have technologies to do either.

I have more to say about some details in the Guardian article from which I got Figure 4.  That will have to wait for another post.  The Science study the article mentions is worthy of discussion, as is the Guardian’s comment that concentrations continue to increase despite government action.  The article also links to a recent study of GHG reductions by 2020.  I will address these in an upcoming post.


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January 2013 CO2 Concentrations: 395.55ppm

Up and up the value goes.  The Scripps Institution of Oceanography measured an average of 395.55ppm CO2 concentration at their Mauna Loa, Hawai’i’s Observatory during January 2013.

395.55ppm is the highest value for January concentrations in recorded history. Last year’s 393.14ppm was the previous highest value ever recorded.  This January’s reading is 2.41ppm higher than last year’s.  This increase is significant.  Of course, more significant is the unending trend toward higher concentrations with time, no matter the month or specific year-over-year value, as seen in the graphs below.

The yearly maximum monthly value normally occurs during May. Last year was no different: the 396.78ppm concentration in May 2012 was the highest value reported last year and in recorded history (neglecting proxy data).  Note that January’s value is only 1.23ppm less than May 2012′s.  If we extrapolate last year’s maximum value out in time, it will only be 2 years until Scripps reports 400ppm average concentration for a singular month (likely May 2014; I expect May 2013′s value will be ~398ppm).  Note that I previously wrote that this wouldn’t occur until 2015 – this means CO2 concentrations are another climate variable that is increasing faster than experts predicted just a short couple of years ago.

It is worth noting here that stations measured 400ppm CO2 concentration for the first time in the Arctic last year.  The Mauna Loa observations are usually closer to globally averaged values than other sites, such as in the Arctic.  That is why scientists and media reference the Mauna Loa observations most often.

 photo co2_widget_brundtland_600_graph_201301_zps47426643.gif

Figure 1 – Time series of CO2 concentrations measured at Scripp’s Mauna Loa Observatory in January: from 1959 through 2012.

This time series chart shows concentrations for the month of January in the Scripps dataset going back to 1959. As I wrote above, concentrations are persistently and inexorably moving upward.  How do concentration measurements change in calendar years?  The following two graphs demonstrate this.

 photo CO2_concentration_5y_trend_NOAA_201302_zpsf91fb45e.png

Figure 2 – Monthly CO2 concentration values from 2009 through 2013 (NOAA).  Note the yearly minimum observation is now in the past and we are three months removed from the yearly maximum value.  NOAA is likely to measure this year’s maximum value at ~398ppm.

 photo CO2_concentration_50y_trend_NOAA_201302_zpsd23ef3f0.png

Figure 3 50 year time series of CO2 concentrations at Mauna Loa Observatory.  The red curve represents the seasonal cycle.  The black curve represents the data with the seasonal cycle removed to show the long-term trend.  This graph shows the recent and ongoing increase in CO2 concentrations.  Remember that as a greenhouse gas, CO2 increases the radiative forcing toward the Earth, which eventually increases lower tropospheric temperatures.

We could instead take a 10,000 year view of CO2 concentrations from ice cores and compare that to the recent Mauna Loa observations.  This allows us to determine how today’s concentrations compare to geologic conditions:

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Figure 4 – Historical (10,000 year) CO2 concentrations from ice core proxies (blue and green curves) and direct observations made at Mauna Loa, Hawai’i (red curve) through the early 2000s.

Or we could take a really, really long view into the past:

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Figure 5 – Historical record of CO2 concentrations from ice core proxy data, 2008 observed CO2 concentration value, and 2 potential future concentration values resulting from lower and higher emissions scenarios used in the IPCC’s AR4.

Note that this last graph includes values from the past 800,000 years, 2008 observed values (~8-10ppm less than this year’s average value will be) as well as the projected concentrations for 2100 derived from a lower emissions and higher emissions scenarios used by the IPCC’s Fourth Assessment Report from 2007.  Has CO2 varied naturally in this time period?  Of course it has.  But you can easily see that previous variations were between 180 and 280ppm and took thousands of years to move between the two.  In contrast, the concentration has, at no time during the past 800,000 years, risen to the level at which it currently exists; nor has the concentration changed so quickly (287ppm to 395ppm in less than two hundred years!).  That is important because of the additional radiative forcing that increased CO2 concentrations impart on our climate system.  You or I may not detect that warming on any particular day, but we are just starting to feel their long-term impacts.

Moreover, if our current emissions rate continues unabated, it looks like a tripling of average pre-industrial concentrations will be our reality by 2100 (278 *3 = 834).  Figure 5 clearly demonstrates how anomalous today’s CO2 concentration values are (much higher than the average, or even the maximum, recorded over the past 800,000 years).  It further shows how significant the projected emission pathways are.  I will point out that our actual emissions to date are greater than the higher emissions pathway shown above.  That means that if we continue to emit CO2 at an increasing rate, end-of-century concentration values would exceed the value shown in Figure 5 (~1100ppm instead of 800).  This reality will be partially addressed in the upcoming 5th Assessment Report (AR5), currently scheduled for public release in 2013-14.

Given our historical emissions to date and the likelihood that they will continue to grow at an increasing rate for at least the next 25 years, we will pass a number of “safe” thresholds – for all intents and purposes permanently as far as concerns our species. It is time to start seriously investigating and discussing what kind of world will exist after CO2 concentrations peak at 850 or 1200ppm. No knowledgeable body, including the IPCC, has done this to date. To remain relevant, I think institutions who want a credible seat at the climate science-policy table will have to do so moving forward.  The work leading up to AR5 will begin to fill in some of this knowledge gap.  I expect most of that work has recently started and will be available to the public around the same time as the AR5 release.  This could potentially cause some confusion in the public since the AR5 will tell one storyline while more recent research might tell a different storyline.

The fourth and fifth graphs imply that efforts to pin any future concentration goal to a number like 350ppm or even 450ppm will be incredibly difficult – 350ppm more so than 450ppm, obviously. Beyond an education tool, I don’t see the utility in using 350ppm – we simply will not achieve it, or anything close to it, given our history and likelihood that economic growth goals will trump any effort to address CO2 concentrations in the near future (as President Obama himself stated in 2012).  That is not to say that we should abandon hope or efforts to do something.  On the contrary, this series informs those who are most interested in action.  With a solid basis in the science, we become equipped to discuss policy options.  I join those who encourage efforts to tie emissions reductions to economic growth through scientific and technological research and innovation.  This path is the only credible one moving forward.


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Climate Sensitivity and 21st Century Warming

I want to write about shoddy opining today.  I will also write about tribalism and cherry-picking; all are disappointing aspects in today’s climate discussion.  In climate circles, a big kerfuffle erupted in the past week that revolves around minutiae and made worse by disinformation.  The Research Group of Norway released a press release that somebody’s research showed a climate sensitivity of ~1.9°C (1.2-2.9°C was the range around this midpoint value) due to CO2-doubling, which is lower than other published values.

Important Point #1: The work remains un-peer reviewed.  It is part of unpublished PhD work and therefore subject to change.

Moving from that context, what happened next?  The Inter-tubes were ablaze with skeptics cheering the results.  Additionally, groups like Investor’s Business Daily jumped on the “global warming is hooey” bandwagon.  Writers like Andy Revkin provided thoughtful analysis.

Important Point #2: Skeptics view some model results as truthful – those that agree with their worldview.

IBD can, of course, opine all it wants about this topic.  What obligation to their readers do they have to disclose their biases, however?  All the other science results are wrong, except this one with which they agree.  What makes the new results so correct when every other result is so absolutely wrong?  Nothing, as I show below.

Important Point #3: These preliminary results still show a sensitivity to greenhouse gas emissions, not to the sun or any other factor.

For additional context, you should ask how these results differ from other results.  What are IBD and other skeptics crowing about?

 photo Climate_Sensitivity_500_zps9f1bcb3a.jpg

Figure 1Distributions and ranges for climate sensitivity from different lines of evidence. The circle indicates the most likely value. The thin colored bars indicate very likely value (more than 90% probability). The thicker colored bars indicate likely values (more than 66% probability). Dashed lines indicate no robust constraint on an upper bound. The IPCC likely range (2 to 4.5°C) is indicated by the vertical light blue bar. [h/t Skeptical Science]

They’re crowing about a median value of 1.9°C in a range of 1.2-2.9°C.  If you look at Figure 1, neither the median nor the range is drastically different from other estimates.  The range is a little smaller in magnitude than what the IPCC reported in 2007.  Is it surprising that if scientists add 10 more years of observation data to climate models, a sensitivity measurement might shift?  The IPCC AR4 dealt with observations through 2000.  This latest preliminary report used observations through 2010.  What happened in the past 10 years that might shift sensitivity results?  Oh, a number of La Niñas, which are global cooling events.  Without La Niñas, the 2000s would have been warmer, which would have affected the sensitivity measurement differently.  No  mention of this breaks into the opinion piece.

Important Point #4: Climate sensitivity and long-term warming are not the same thing.

The only case in which they are the same thing is if we limit our total emissions so that CO2 concentrations are equal to CO2-doubling.  That is, if CO2 concentrations peak at 540ppm sometime in the future, the globe will likely warm no more than 1.9°C.  Note that analysis’s importance.  It brings us to:

Important Point #5: On our current and projected emissions pathway, we will more than double pre-industrial CO2 concentrations.

 photo CO2_Emissions_IPCC_Obs_2011_zpsa00aa5e8.jpg

Figure 2.  Historical emissions (IEA data – black) compared to IPCC AR4 SRES scenario projections (colored lines).

As I’ve discussed before, our historical emissions continue to track at the top of the range considered by the IPCC in the AR4 (between A2 and A1FI).  Scientists are working on the AR5 as we speak, but the framework for the upcoming report changed.  Instead of emissions, planners built Representative Concentration Pathways (RCPs) for the AR5.  A graph that shows these pathways is below.  This graph uses emissions to bridge between the AR4 and AR5.

 photo CO2EmissionsScenarios-hist-and-RCP-2012.png

Figure 3. Representative Concentration Pathways used in the upcoming AR5 through the year 2100, displayed using yearly emissions estimates.

The top line (red; RCP8.5) corresponds to the A1FI/A2 SRES scenarios.  As Figure 3 shows, our historical emissions most closely match the RCP8.5 pathway.  The concentration for this pathway through 2100 is 1370ppm CO2-eq, which results in an anomalous +8.5W/m^2 forcing.  This forcing is likely to result in 4 to 6.1°C warming by 2100.  A couple of critical points: in this scenario, emissions don’t peak in the 21st century; therefore this scenario projects additional warming in the 2100s.  I want to make absolutely clear this point: our business-as-usual concentration pathway blows past CO2-doubling this century, which means the doubling sensitivity is a moot point.  We should investigate CO2-quadrupliung.  Why?  The peak emissions and concentration, which dictates the peak anomalous forcing, which controls the peak warming we face.

The IBD article contains plenty of skeptic-speak: “Predictions of doom have turned out to be nothing more than madness”, “there are too many unknowns, too many variables”, and “nothing ever proposed would have any impact anyway”.

They do have a point with their first quoted statement.  I avoid catastrophic language because doom has not befallen the vast majority of people on this planet.  Conditions are changing, to be sure, but not drastically.  There are too many unknowns.  Most of the unknowns scientists worked on the last 10 years ended up with the opposite result that IBD assumes: scientists underestimated feedbacks and results.  Events unfolded much more quickly than previously projected.  That will continue in the near future due mainly to our lack of knowledge.  The third point is a classic: we cannot act because others will not act in concert with us.  This flies in the face of a capitalist society’s foundation.  Does IBD really believe that US innovation will not increase our competitiveness or reduce inefficiencies?  Indeed, Tim Worstall’s Forbes piece posited a significant conclusion: climate change becomes cheaper to solve if the sensitivity is lower than previously estimated.  IBD should be cheering for such a result.

Finally, when was the last time you saw the IBD latch onto one financial model and completely discard others?  Where was IBD in 2007 when the financial crisis was about to start and a handful of skeptics warned that the mortgage boom was based on flawed models?  Were they writing opinion pieces like this one?  I don’t think so.  Climate change requires serious policy consideration.  This opinion piece does nothing to materially advance that goal.


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State of Polar Sea Ice – January 2013: Arctic Below and Antarctic Above Normal

Global polar sea ice area in early January 2013 remains below climatological normal conditions (1979-2009), but has improved in the past month.  Antarctic sea ice loss is occurring at a climatological normal rate.  Arctic sea ice gain is slightly more rapid than normal, but we should expect this given the record low extent that occurred in September 2012.  Polar sea ice recovered from an extensive deficit of -2.5 million sq. km. area late last year to a -500,000 sq. km. anomaly within the last week.

In March-April 2012, global sea ice area was above normal, but sea ice area anomaly quickly turned negative and then spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2012.  Generally poor environmental conditions (warm surface temperatures and certain wind patterns) established and maintained this condition, predominantly across the Arctic last year.  For the third time in modern history, the minimum global sea ice area fell below 17.5 million sq. km. and for the fourth time in modern history, the anomalous global sea ice area fell below -2 million sq. km.  This is a significant development given that Antarctic sea ice area has been slightly above average during the past few years.  This means that the global anomaly is almost entirely due to worsening Arctic ice conditions.

The rapid ice melt and record-setting area and extent values that occurred in 2012 are the top weather/climate story for 2012, in my opinion.  I think we have clearly seen a switch to new conditions in the Arctic.  Whether these events will occur in similar magnitude or are merely transitory as the Arctic continues to move to a new stable state that the climate will not achieve for years or decades remains to be seen.  The problem is we don’t know all of the ramifications of moving toward or achieving that new state.  Additionally, I don’t think we want to know.

Arctic Ice

According to the NSIDC, weather conditions once again caused less freezing to occur on the Atlantic side of the Arctic Ocean and more freezing on the Pacific side.  Similar conditions occurred during the past six years.  Sea ice creation during December measured 2.33 million sq. km.  Despite this rather rapid growth, December′s extent remained far below average for the month.  Instead of measuring near 13.36 million sq. km., December 2012′s extent was only 12.2 million sq. km., a 1.16 million sq. km. difference!  The Barents and Kara Seas remained ice-free, which is a very unusual condition for them in December.  Recent ice growth in the Seas has slightly alleviated this state, but this is happening very late in the season.  The Bering Sea, which saw ice extent growth due to anomalous northerly winds in 2011-2012, saw similar conditions in December 2012.  This has caused anomalously high ice extent in the Bering Sea.  Temperatures over the Barents and Kara Seas were 5-9°F above average while temperatures over Alaska were 4-13°F below average.  The reason for this is another negative phase of the Arctic Oscillation, which allows cold Arctic air to move southward.  This allows warm sub-arctic air to move north.

In terms of longer, climatological trends, Arctic sea ice extent in December has decreased by 3.5% per decade.  This rate is closest to zero in the spring months and furthest from zero in late summer/early fall months.  Note that this rate also uses 1979-2000 as the climatological normal.  There is no reason to expect this rate to change significantly (more or less negative) any time soon, but increasingly negative rates are likely in the foreseeable future.  Additional low ice seasons will continue.  Some years will see less decline than other years (like this past year) – but the multi-decadal trend is clear: negative.  The specific value for any given month during any given year is, of course, influenced by local and temporary weather conditions.  But it has become clearer every year that humans have established a new climatological normal in the Arctic with respect to sea ice.  This new normal will continue to have far-reaching implications on the weather in the mid-latitudes, where most people live.

Arctic Pictures and Graphs

The following graphic is a satellite representation of Arctic ice as of September 17, 2012 (yes, it’s been that long since I’ve written a Polar post):

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Figure 1UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20120917.

Here is the similar image from January 9, 2013:

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Figure 2UIUC Polar Research Group‘s Northern Hemispheric ice concentration from 20130109.

September’s picture shows the minimum extent that occurred in 2012.  You can easily see the substantial growth of sea ice since then.  This comparison provides a good opportunity to point out something important: even in an epoch of anthropogenic global warming, the Arctic will continue to see wintertime sea ice.  There is no solar radiation warming the surface directly and temperatures fall well below freezing for a long time.  The loss of sea ice will continue to occur and will worsen significantly in the summer.  That loss of ice when the sun is overhead is what climate scientists expect to drive numerous changes around the globe.  Incoming solar radiation, instead of being largely reflected back out into space, will instead be mostly absorbed by a darker ocean.  That radiation will stay in the Earth’s climate system as heat, which will cause many cascading effects to occur – effects we largely do not know about because we’ve never lived on a planet with missing summer sea ice at a pole.

The lack of sea ice in the Barents and Kara Seas (north of Europe and far western Russia) is problematic because wind and ocean currents typically pile sea ice up on the Atlantic side of the Arctic.  Sea ice presence in the Bering Sea (between Alaska and Russia) does not alleviate this problem because currents take ice from that area and transport it into the Arctic.  That sea ice will be among the first to melt completely come spring.  With sea ice missing on the Atlantic side, currents will transport Arctic sea ice to southern latitudes where it melts.  The possibility that January’s picture will look similar to September’s picture is therefore higher in 2013 than it was in say 1983.

Overall, the health of the remaining ice pack is not healthy, as the following graph of Arctic ice volume from the end of December demonstrates:

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Figure 3PIOMAS Arctic sea ice volume time series through December 2012.

As the graph shows, volume (length*width*height) hit another record minimum in June 2012.  Moreover, the volume is far, far outside the 2 standard deviation envelope (lighter gray contour surrounding the darker gray contour and blue median value).  I understand that most readers don’t have an excellent handle on statistics, but conditions between -1 and -2 standard deviations are rare and conditions outside the -2 standard deviation threshold (see the line below the shaded area on the graph above) are incredibly rare: the chances of 3 of them occurring in 3 subsequent years under normal conditions are extraordinarily low (you have a better chance of winning your state lottery than this).  Hence my assessment that “normal” conditions in the Arctic are shifting from what they were in the past few centuries; a new normal is developing.  Note further that the ice volume anomaly returned to near the -1 standard deviation envelope in early 2011, early 2012, and now early 2013.  In each of the previous two years, volume fell rapidly outside of the -2 standard deviation area with the return of summer.  That means that natural conditions are not the likely cause; rather, another cause is much more likely to be responsible for this behavior: human influence.

Arctic Sea Ice Extent

Take a look at December’s areal extent time series data:

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Figure 4NSIDC Arctic sea ice extent time series through early January 2013.

As you can see, the extent (light blue line) grew rapidly in October, then remained at historically low levels through November and December.  The extent remained well below average values (thick gray line) throughout the fall and early winter.  The time series of sea ice extent for previous low years is also shown on this graph, which is what I term NSIDC’s supplemental graph.  In this month’s version, they also plotted the previous five years’ data.  You can see the effect of the winter-time conditions that I described above: the difference between a year’s extent and the average value in Jan/Feb is smaller than the difference in October.  This leads us to examine the differences between the historical mean, the negative two standard deviation (light gray) below that mean, and the 2012-2013 time series.  I can come up with a number of adjectives to describe that difference, but I’ll settle with “stunning”.

Antarctic Pictures and Graphs

Here is a satellite representation of Antarctic sea ice conditions from September 17th:

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Figure 5UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20120917.

And here is the corresponding graphic from January 9th:

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Figure 6UIUC Polar Research Group‘s Southern Hemispheric ice concentration from 20130109.

Ice loss is easily visible around the continent, the more so since there is a 3+ month time difference between Figures 5 and 6.  There is slightly more Antarctic sea ice today than there normally is on this date in the year.  As a reminder, the difference between long-term Arctic ice loss and relative lack of Antarctic ice loss is largely and somewhat confusingly due to the ozone depletion that took place over the southern continent in the 20th century.  This depletion has caused a colder southern polar stratosphere than it otherwise would be, reinforcing the polar vortex over the Antarctic Circle.  This is almost exactly the opposite dynamical condition than exists over the Arctic with the negative phase of the Arctic Oscillation.  The southern polar vortex has helped keep cold, stormy weather in place over Antarctica that might not otherwise would have occurred to the same extent and intensity.  As the “ozone hole” continues to recover during this century, the effects of global warming will become more clear in this region, especially if ocean warming continues to melt sea-based Antarctic ice from below (subs. req’d).  For now, we should perhaps consider the lack of global warming signal due to lack of ozone as relatively fortunate.  In the next few decades, we will have more than enough to contend with from melting on Greenland.  Were we to face melting West Antarctic Ice Sheet at the same time, we would have to allocate many more resources.  Of course, in a few decades, we’re likely to face just such a situation.

Finally, here is the Antarctic sea ice extent time series from January 9th:

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Figure 8NSIDC Antarctic sea ice extent time series through early January 2013.

Antarctic sea ice extent remained at or above average to some extent through the austral spring and early summer, which is good news.

Policy

I just read an opinion piece in Scientific American regarding the sorry state of Arctic sea ice. The author, a scientist, advocated that we do not have time to negotiate mitigation treaties. In order to save the ice, we have to research and deploy geoengineering technologies. Let me state by position on this clearly and strongly: we do not know the effects from geoengineering (solar radiation management or carbon dioxide removal) and more than the know the range and magnitude of effects from greenhouse gas emissions. Moreover, basic governance structures for geoengineering research do not currently exist, to say nothing of deployment. If you think international climate policy is complex and hasn’t moved forward quickly, you should think long and hard before advocating for geoengineering research and deployment. Single-actors are probably the biggest worry when you consider the lack of accountability if somebody conducts an experiment. The few small-scale experiments that have come close to real-world execution by national government scientists around the world caused quick and severe public outcries. The main reason for this is something that affects most scientific endeavors: the lack of effective communication with the public prior to carrying out research.  Engaging the public could be viewed as surrendering power and autonomy.  But I view it as a critical component to continued public funding of science and technology research.

Errata

Here are my State of the Poles posts from September and July.

You can find NSIDC’s January report here.


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December 2012 CO2 Concentrations: 394.39ppm

The Scripps Institution of Oceanography measured an average of 394.39ppm CO2 concentration at their Mauna Loa, Hawai’i’s Observatory during December 2012.

394.39ppm is the highest value for December concentrations in recorded history. Last year’s 391.79ppm was the previous highest value ever recorded.  This December’s reading is 2.60ppm higher than last year’s.  This increase is significant.  Of course, more significant is the unending trend toward higher concentrations with time, no matter the month or specific year-over-year value, as seen in the graphs below.

The yearly maximum monthly value normally occurs during May. Last year was no different: the 396.78ppm concentration in May 2012 was the highest value reported this year and in recorded history (neglecting proxy data).  Note that December 2012′s value is only 2.39ppm less than May 2012′s.  If we extrapolate last year’s maximum value out in time, it will only be 2 years until Scripps reports 400ppm average concentration for a singular month (likely May 2014; I expect May 2013′s value will be ~398ppm).  Note that I previously wrote that this wouldn’t occur until 2015 – another climate variable that is increasing faster than energy or climate experts predicted.

It is worth noting here that stations measured 400ppm CO2 concentration for the first time in the Arctic last year.  The Mauna Loa observations represent more well-mixed (global) conditions while sites in the Arctic and elsewhere more accurately measure local and regional concentrations.  That is why scientists and media reference the Mauna Loa observations most often.

Earlier last year, I predicted that 2012 would not see an average monthly CO2 concentration below 390ppm.  I was correct: September and October 2012 concentration values were the lowest recorded last year (391ppm).  It wasn’t the hardest prediction to make: the trend was going up at a steady rate and based on humanity’s continued reliance on fossil fuels, we weren’t going to break that trend.  The next prediction to verify is the first month at Mauna Loa during which Scripps records an 400ppm average.  After that, the first year during which the minimum concentration is at least 400ppm, which I think will occur within the next 5 years.

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Figure 1 – Time series of CO2 concentrations measured at Scripp’s Mauna Loa Observatory in December: from 1958 through 2012.

This time series chart shows concentrations for the month of December in the Scripps dataset going back to 1958. As I wrote above, concentrations are persistently and inexorably moving upward.  How do concentration measurements change in calendar years?  The following two graphs demonstrate this.

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Figure 2 – Monthly CO2 concentration values from 2008 through 2013 (NOAA).  Note the yearly minimum observations are now in the past and we are five months removed from the yearly maximum value.

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Figure 3 50 year time series of CO2 concentrations at Mauna Loa Observatory.  The red curve represents the seasonal cycle.  The black curve represents the data with the seasonal cycle removed to show the long-term trend.  This graph shows the ongoing increase in CO2 concentrations.  Remember that as a greenhouse gas, CO2 increases the radiative forcing toward the Earth, which eventually increases lower tropospheric temperatures.

We could instead take a 10,000 year view of CO2 concentrations from ice cores and compare that to the recent Mauna Loa observations.  This allows us to determine how today’s concentrations compare to geologic conditions:

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Figure 4 – Historical (10,000 year) CO2 concentrations from ice core proxies (blue and green curves) and direct observations made at Mauna Loa, Hawai’i (red curve).

Or we could take a really, really long view into the past:

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Figure 5 – Historical record of CO2 concentrations from ice core proxy data, 2008 observed CO2 concentration value, and 2 potential future concentration values resulting from lower and higher emissions scenarios used in the IPCC’s AR4.

Note that this last graph includes values from the past 800,000 years, 2008 observed values (~8-10ppm less than this year’s average value will be) as well as the projected concentrations for 2100 derived from a lower emissions and higher emissions scenarios used by the IPCC’s Fourth Asssessment Report from 2007.  Has CO2 varied naturally in this time period?  Of course it has.  But you can easily see that previous variations were between 180 and 280ppm.  In contrast, the concentration has, at no time during the past 800,000 years, risen to the level at which it currently exists.  That is important because of the additional radiative forcing that increased CO2 concentrations impart on our climate system.  You or I may not detect that warming on any particular day, but we are just starting to feel their long-term impacts.

Moreover, if our current emissions rate continues unabated, it looks like a tripling of average pre-industrial concentrations will be our reality by 2100 (278 *3 = 834).  Figure 5 clearly demonstrates how anomalous today’s CO2 concentration values are (much higher than the average, or even the maximum, recorded over the past 800,000 years).  It further shows how significant projected emission pathways are.  I will point out that our actual emissions to date are greater than the higher emissions pathway shown above.  That means that if we continue to emit CO2 at an increasing rate, end-of-century concentration values would exceed the value shown in Figure 5.  This reality will be partially addressed in the upcoming 5th Assessment Report (AR5), currently scheduled for public release in 2013-14.

Given our historical emissions to date and the likelihood that they will continue to grow at an increasing rate for at least the next 25 years, we will pass a number of “safe” thresholds – for all intents and purposes permanently as far as concerns our species. It is time to start seriously investigating and discussing what kind of world will exist after CO2 concentrations peak at 850 or 1200ppm. No knowledgeable body, including the IPCC, has done this to date. To remain relevant, I think institutions who want a credible seat at the climate science-policy table will have to do so moving forward.  The work leading up to AR5 will begin to fill in some of this knowledge gap.  I expect most of that work has recently started and will be available to the public around the same time as the AR5 release.  This could potentially cause some confusion in the public since the AR5 will tell one storyline while more recent research might tell a different storyline.

The fourth and fifth graphs imply that efforts to pin any future concentration goal to a number like 350ppm or even 450ppm will be incredibly difficult – 350ppm more so than 450ppm, obviously. Beyond an education tool, I don’t see the utility in using 350ppm – we simply will not achieve it, or anything close to it, given our history and likelihood that economic growth goals will trump any effort to address CO2 concentrations in the near future (as President Obama himself stated in 2012).  That is not to say that we should abandon hope or efforts to do something.  On the contrary, this series informs those who are most interested in doing something.  With a solid basis in the science, we become well equipped to discuss policy options.  I join those who encourage efforts to tie emissions reductions to economic growth through scientific and technological research and innovation.  This path is the only credible one moving forward.


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November 2012 CO2 Concentrations: 392.92ppm

The Scripps Institution of Oceanography measured an average of 392.92ppm CO2 concentration at their Mauna Loa, Hawai’i’s Observatory during November 2012.

392.92ppm is the highest value for November concentrations in recorded history. Last year’s 390.31ppm was the previous highest value ever recorded.  This November’s reading is 2.61ppm higher than last year’s.  This increase is significant.  Of course, more significant is the unending trend toward higher concentrations with time, no matter the month or specific year-over-year value, as seen in the graphs below.

The yearly maximum monthly value normally occurs during May. This year was no different: the 396.78ppm concentration in May 2012 was the highest value reported this year and in recorded history (neglecting proxy data).  If we extrapolate this year’s maximum value out in time, it will only be 2 years until Scripps reports 400ppm average concentration for a singular month (likely May 2014).  Note that I previously wrote that this wouldn’t occur until 2015 – another climate variable that is increasing faster than energy or climate experts predicted.

I’ve seen comments in the skeptic blogosphere that CO2 measured at Mauna Loa should be higher than anywhere else because of its elevation and specific location.  This is an effort to challenge the credibility of the dataset.  It is important to understand that this statement exists somewhere between correct to purposefully confusing to outright deceitful.  CO2 is a well-mixed constituent of the atmosphere.  That means that emissions of new CO2 are quickly and pretty evenly distributed in space.  While point locations might vary between each other (differences between polar and tropical CO2 concentrations at the same point in time vary the most, for example), the observations at Mauna Loa are very representative of those found across the set of observation stations on the globe.  In addition, as the graphs below will help demonstrate, the historical record is very clear – concentrations have done only one thing in the past 50+ years at any station you want to discuss: increased.  There has been no plateauing or decrease in that time period.

That being said, it is worth noting here that stations measured 400ppm CO2 concentration for the first time in the Arctic earlier this year.  The Mauna Loa observations represent more well-mixed (global) conditions while sites in the Arctic and elsewhere more accurately measure local and regional concentrations.  That is why scientists and media reference the Mauna Loa observations most often.

Earlier in the year, I predicted that 2012 would not see an average monthly CO2 concentration below 390ppm.  It wasn’t the hardest prediction to make: the trend was going up at a steady rate and based on humanity’s continued reliance on fossil fuels, we weren’t going to break that trend this year.  The next prediction to verify is the first month at Mauna Loa during which Scripps records an 400ppm average.  After that, the first year during which the minimum concentration is at least 400ppm, which I think will occur within the next 5 years.

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Figure 1 – Time series of CO2 concentrations measured at Scripp’s Mauna Loa Observatory in November: from 1958 through 2012.

This time series chart shows concentrations for the month of November in the Scripps dataset going back to 1958. As I wrote above, concentrations are persistently and inexorably moving upward. Alternatively, we could take a 10,000 year view of CO2 concentrations from ice cores and compare that to the recent Mauna Loa observations:

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Figure 2 – Historical (10,000 year) CO2 concentrations from ice core proxies (blue and green curves) and direct observations made at Mauna Loa, Hawai’i (red curve).

Or we could take a really, really long view into the past:

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Figure 3 – Historical record of CO2 concentrations from ice core proxy data, 2008 observed CO2 concentration value, and 2 potential future concentration values resulting from lower and higher emissions scenarios used in the IPCC’s AR4.

Note that this graph includes values from the past 800,000 years, 2008 observed values (~6-8ppm less than this year’s average value will be) as well as the projected concentrations for 2100 derived from a lower emissions and higher emissions scenarios used by the IPCC’s Fourth Asssessment Report from 2007.  Has CO2 varied naturally in this time period?  Of course it has.  But you can easily see that previous variations were between 180 and 280ppm.  In contrast, the concentration has, at no time during the past 800,000 years, risen to the level at which it currently exists.  That is important because of the additional radiative forcing that increased CO2 concentrations impart on our climate system.  You or I may not detect that warming on any particular day, but we are just starting to feel their long-term impacts.

Moreover, if our current emissions rate continues unabated, it looks like a tripling of average pre-industrial concentrations will be our reality by 2100 (278 *3 = 834).  This graph clearly demonstrates how anomalous today’s CO2 concentration values are (much higher than the average recorded over the past 800,000 years).  It further shows how significant projected emission pathways are.  I will point out that our actual emissions to date are greater than the higher emissions pathway shown above.  This reality will be partially addressed in the upcoming 5th Assessment Report (AR5), currently scheduled for public release in 2013-14.

Given our historical emissions to date and the likelihood that they will continue to grow at an increasing rate for at least the next 25 years, we will pass a number of “safe” thresholds – for all intents and purposes permanently as far as concerns our species. It is time to start seriously investigating and discussing what kind of world will exist after CO2 concentrations peak at 850 or 1100ppm. No knowledgeable body, including the IPCC, has done this to date. To remain relevant, I think institutions who want a credible seat at the climate science-policy table will have to do so moving forward.  The AR5 might possibly fill in some of this knowledge gap.  I expect most of that work has recently started and will be available to the public around the same time as the AR5 release, which is likely to cause some confusion in the public.

As the second and third graphs imply, efforts to pin any future concentration goal to a number like 350ppm or even 450ppm will be incredibly difficult – 350ppm more so than 450ppm, obviously. Beyond an education tool, I don’t see the utility in using 350ppm – we simply will not achieve it, or anything close to it, given our history and likelihood that economic growth goals will trump any effort to address CO2 concentrations in the near future (as President Obama himself stated recently).  That is not to say that we should abandon hope or efforts to do something.  On the contrary, this series informs those who are most interested in doing something.  With a solid basis in the science, we become well equipped to discuss policy options.  I join those who encourage efforts to tie emissions reductions to economic growth through scientific and technological research and innovation.  This path is the only credible one moving forward.


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State of the Poles – Mid-September 2012: Record Low Arctic Ice Extent; Antarctic Ice Above Climatological Normal

Judging by recent search terms used to get to this blog and the relative recent peak in traffic, readers have been searching for this post.  I wanted to wait a little longer into the month so that I could capture the expected Arctic minimum, which officially occurred on the 16th of September.  The NSIDC announced this date, after which I started gathering the plots that are found below.  This post will be longer than it usually is because this year’s minimum shattered the record minimum set in 2007, which shattered the previous record set in 2005.  Most of the post is made up of figures, so I encourage readers to at least view them to get a good picture of today’s conditions.  I’m purposefully framing things this way to relay the truly stunning situation the Arctic is in today.  2012 is additional proof the Arctic cryosphere is searching for a new stable point, but hasn’t found it yet.  That does not bode well for the rest of the globe.  With that, let’s begin.

The state of global polar sea ice area in mid-September 2012 remains significantly below climatological normal conditions (1979-2009).  Arctic sea ice loss is solely responsible for this condition.  In fact, if Antarctic sea ice were closer to its normal value, the global area would be much lower than it is today.  Arctic sea ice melted quickly in August and the first half of September because it was thinner than usual and winds helped push ice out of the Arctic where it could melt at lower latitudes; Antarctic sea ice has refrozen at a faster than normal rate during the austral winter.  Polar sea ice recovered from an extensive deficit of -2 million sq. km. area late last year to a +750,000 sq. km. anomaly in March 2012 before falling back to a -2.2 million sq. km. deficit earlier this month.

After starting the year at a deficit from normal conditions, sea ice area spent an unprecedented length of time near the -2 million sq. km. deficit in the modern era in 2011 (i.e., almost the entire calendary year).  Generally poor environmental conditions (warm surface temperatures and certain wind patterns) established and maintained this condition, predominantly across the Arctic last year.  The last time global sea ice area remained near 19 million sq. km. during May was in 2007, when the Arctic extent hit its modern day record minimum.  The maximum in the boreal spring the past two years was ~19.5 million sq. km.

Conditions were prime for another modern-day record sea ice extent minimum to occur in September.  Specific weather conditions helped to determine how 2012′s extent minimum ranks compared to the last 33 years, but it was the overall poor condition of Arctic sea ice that contributed to this year’s record low values.

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Climate Change Basics – Energy & Projections

In July, I wrote a post that laid the groundwork for the discussion of climate change basics: Gases, Forcing & Surface Temperature.  This post follows onto that initial post by discussing energy within Earth’s climate system.  As in that post, I will focus on the results in the IPCC’s AR4.  There is a wealth of additional results in the scientific literature since the 2007 Report and I will share some of those in future posts.  In other words, the IPCC information will be used as a baseline.  This post is a little long, but I think it’s worth reading in its entirety.

Energy Content

First, here are two views of the energy content in the climate system.  The first is from the IPCC’s WGI Technical Summary:

Source: IPCC AR4 Figure TS.15.  Energy content changes in different components of the Earth for two periods (1961-2003 (blue) and 1993-2003 (burgundy)).

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Climate Change Basics – Gases, Forcing & Surface Temperature

After running across some resources again recently, I thought it would be a good idea to put some posts together that showed the background of many of the common facts I discuss.  In this first post, I wanted to show the relationship between greenhouse gases, radiative forcing and temperatures.  In doing, I will use graphics from the IPCC’s 4th Assessment Report Technical Summary.

First, here is a graphic of changes in greenhouse gases from ice core and modern observational data, spanning the time period of 20,000 years ago through current:

The portion of this graph I’d like to focus on is the upper left quadrant displaying the time series of atmospheric carbon dioxide concentration.  First, note is the transition from ~180ppm 20,000 years ago to between 260 and 280ppm.  This transition helped bring the last interglacial period to an end.  Of greater import is the more recent transition from 280ppm to 380ppm (as of ~2005; current concentrations are ~390ppm).

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2010 Warmest Year On Record, Says NASA & NOAA

The news is in and it isn’t good.  Despite a strong La Nina during the second half of the year and cold air able to escape the Arctic and affect Europe and the eastern U.S., 2010 was the warmest year since 1880.

The top-10 warmest years in the NASA record are now:

2010, 2005 (actually 0.018°F less than 2010), 1998, 2002, 2003, 2006, 2007, 2009, 2004 and 2001.

9 out of the 10 warmest years on record have now all occurred since 2002.  The 12 warmest years on record have occurred since 1997.  Global warming has not stopped.  Global warming will not stop unless and until we stop polluting the climate system with greenhouse gas emissions at a tiny fraction of our current pace.

NOAA has put together their annual global report, which acts as confirmation of the NASA result: 2010 is statistically tied with 2005 as the warmest year in their dataset.

To the climate zombies that infest the discussion over what to do about global warming, consider the following: 2010 was “only” 1.12°F (0.62°C) above the 20th century average of 59.0°F.  Our current emissions trajectory is closest to the A1FI emissions scenario in the IPCC’s SRES family.  Results of running that scenario through climate models produced the following results: best estimate temperature rise of 7.2°F with a likely range of 4.3 to 11.5°F (4.0 °C with a likely range of 2.4 to 6.4 °C).

Multiple extreme weather events also characterized 2010 and continue to do so in early 2011.  From a heat wave worse than any seen in the past few thousand years across eastern Europe and Russia that claimed many lives and spawned massive wildfires to related Pakistani floods that affected tens of millions of people to floods in Australia that cover more area than several countries in Europe, loaded die are starting to land.  The costs of these disasters already reach into the tens to hundreds of billions of dollars.  If these kinds of horrific events are already occurring with only 1.12°F warming, what will happen when the globe warms by an average of 4.3°F, 7.2°F, or even 11.5°F?  It can be summed up simply: stress will move beyond impacting disparate societies; our civilizations will be stressed to breaking points, to say nothing of ecosystems across the planet.

Cross-posted at SquareState.

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