An arctic air mass plunged down the east side of the Rocky Mountains in the past day. This air mass will cause record low temperatures for the Denver, CO area. According to the NWS, the record low maximum temperature for April 9th is 27F, which was set in 1973. The record low minimum temperature for April 9th is 12F, which was set in 1959. The temperature at DIA at midnight this morning was 24F. The maximum temperature during the day today will not be higher than 20F, which means the calendar day’s maximum temperature has likely already been set. It’s 15F right now, which is quite frigid for April in Denver.
The storm system that brought this cold air to the area was also supposed to bring considerable snow. Yesterday’s forecast predicted up to 12″. Because of the chaotic nature of the atmosphere, Denver will not receive 12″ of snow. The upper level low split into two smaller pieces as it tried to traverse the intermountain west. This development is not unusual, but numerical models have a hard time handling this behavior due to their limited resolution. When upper level lows split, the energy associated with the storm also splits. So instead of 12″ over the Denver area, lower amounts will be spread over a larger area. The timing of vertical lift and the passage of a series of cold fronts through Denver also affected the beginning of precipitation. Rain was supposed to fall starting around 6P last night, then switch to snow between 9P and midnight. Instead, light snow started to fall around 10P.
This storm system is part of a different pattern than what occurred last year. During early April 2012, record maximum temperatures were set. Most of the change is due to simple interannual weather and climate variability, including low-frequency climate oscillations like the El Nino-Southern Oscillation and the Interdecadal Pacific Oscillation. We can attribute part of the change to the underlying warming climate, which impacts those climate oscillations.
Climate change skeptics will likely point to this storm and the record lows that the NWS will record as “proof” that a warming climate is not occurring. To the contrary, there is a climate-related reason why this storm system is impacting the western US today and bringing record warm temperatures to the eastern US. The following plot shows today’s jet stream configuration:
The strength of the jet stream is characterized by the speed of the winds. As the figure shows, there are very fast winds on the west side of the trough over the western US (red-filled contour where winds are in excess of 125 knots). There are very slow winds south of Louisiana and east of northern Florida. I have included an arrow on this figure to highlight the climate-related impact. As the Arctic warmed more than the equatorial region, the temperature gradient weakened. Temperature gradients cause pressure and density gradients (Ideal Gas Law). As the average annual equator-pole temperature gradient weakens, the average pressure gradient similarly weakens. This reduced pressure gradient causes the west-to-east movement of storm systems to slow down. The arrow above highlights the amplitude of the current wave traversing North America. This wave’s amplitude is characterized as high due to its large latitudinal extent (it stretches from Mexico to northern Canada, which is a very large distance). This high amplitude simultaneously causes cold air to move from the Arctic to more southerly locations, such as Denver, CO, and warm air to move from the sub-tropics to more northerly locations, such as the eastern US.
Absent long-term anthropogenic climate change, this storm system would be much less likely to move slowly and bring record low temperatures to the middle of the US. Instead, the storm would move quickly across the country. Denver would receive cooler than average temperatures, but not record cold temperatures. The cold air would remain further north and impact Canada and the northern US.
To summarize, climate change will not banish record low temperatures. They will become more rare, however. Winter will still occur in the mid- and high-latitudes. But those winters will, on average, become warmer in the future. Precipitation that would have fallen as snow in the 20th century will be likelier to fall as rain as the 21st century progresses. More precipitation will likely fall during each event, but there will be longer time periods between precipitation events. Overall, aridity will increase and flash flooding could become a more common problem for communities.
Thankfully, the NWS predicts temperatures to return to normal by this weekend. I’m sure happy to receive the precipitation, but I wish it came as rain and left the Arctic air up in the Arctic.
A quick word and some questions on a SkepticalScience post that discusses yet another warming analysis that comes up with the same answer than other studies have. The post itself is good if you want a paper summary. Where I think it needs attention is the “so what” part. I’ll start with the concluding paragraph because it is what triggered a desire to actually write something about the post instead of walking away from it.
How much more evidence do we need? The accuracy of the instrumental global surface temperature record is essentially settled science at this point. The Earth is warming, it’s warming very fast, and continuing to deny this fact is a waste of time.
Many researchers and activists won’t like my answer: we don’t need much more scientific evidence. Indeed, I would argue that the science largely weighed in years ago and additional information has only provided small-scale refocusing on parts of the issue. Scientists haven’t discovered anything truly transformative in many years. Are fields advancing as a result of new observations, methodologies, and expertise. Yes, but that doesn’t answer Dana’s question. What climate field advancement will be the one that magically triggers a switch in skeptics’ minds? What new data set or analysis technique will do the trick? I argue that no such advancement will ever occur. Do we really believe that nobody has yet been smart enough to develop the one advancement that unlocks universal understanding of a complex topic? That’s clearly an absurd assumption, but it seems to permeate this and other similar posts. The spectrum of people who care about this topic have made up their minds (whether through tribalism or critical thought). I will not convince any large number of skeptics to accept my argument any more than Hansen, Gore, or McKibben. And here is where things get raw: strategies that those activists and most others have employed will not convince those people who don’t care about this topic. As voices get more shrill and combative, more people tune the arguers out.
So if the evidence isn’t the problem, what is? I believe the problem is the use of climate science as a proxy for a values fight. Most people are unwilling to identify and fight about their values; it is much easier to throw climate science in the middle of the ring to fight for them. Skeptics challenge the “facts” because of their beliefs and value system. Advocates challenge the skeptics because of their beliefs and value system, not because of the “facts”. Both groups try to bludgeon each other with “facts” and in so doing talk past each other, not to each other. What concerns do skeptics have regarding climate change; how can advocates listen and address those concerns and vice versa. Bypassing others’ concerns is the thing that wastes time. So why do advocates and skeptics do it so much?
The EU auction failed because bids didn’t reach a secret reserve price. “In the past five years, carbon prices on the ETS have plummeted nearly 90 percent.” The core problem with the ETS is oversupply of credits. The article points out possible solutions: backloading or long-term structural change. I’m not an expert on carbon markets, but my understanding leads me to support the long-term structural change course. The ETS tried to please too many vested interests simultaneously (too complex) and resulted in pleasing too few while not achieving its core objective of emissions reductions resulting from a market signal.
On the other hand, The Regional Greenhouse Gas Initiative had its successful 19th auction of CO2 allowances earlier this month. I wouldn’t characterize it as bad news, but the clearing price of $2.80 per ton, above the reserve price of $1.98 per ton, is too low to directly impact CO2 emissions; it is also lower than the price in Europe and California. Utilities in the region are switching to cheaper fuel sources because they’re cheaper, not because they emit fewer CO2 emissions. According to the article, a significant portion (63%) of the $105.9 million in this quarter’s revenue and the $617 million in historical revenue are earmarked for clean energy technologies like energy efficiency, renewables, and climate change adaptation across RGGI’s nine Northeast US member states. I would certainly like to read a more in-depth analysis of this claim. Where specifically have the investments gone and what are the results to date?
The RGGI realizes their reserve and clearing price are too low:
Just over a month ago, the RGGI states decided to reduce the 2014 CO2 budget (the “cap” in cap-and-trade) from 165 million to 91 million tons and retire unsold 2012 and 2013 allowances. This 45% cut is expected to boost allowance prices to $4 per ton in 2013 and up to $10 per ton in 2020, creating billions of new revenue every year. By comparison, RGGI allowance auction clearing prices have never risen higher than $3.51.
That 2020 price is still too low to have much of a direct impact on carbon emissions. The obvious benefit is the additional revenue however. The more revenue we have available to invest in innovation and deploy efficient infrastructure and technologies, the more we will decrease CO2 emissions. The investment portion of the RGGI policy is a positive feature (I have read less about what the EU does with ETS revenue; I don’t claim with certainty that the RGGI system is “better” than the ETS system). Any national-level tax-and-dividend system will be complex. But even$20 per ton today would not, absent subsidies, provide enough incentive for utilities to switch from fossil fuels to zero-carbon sources.
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 than normal this winter. Similar conditions occurred during the past six boreal winters. Sea ice creation during February measured 766,000 sq. km. Despite this rather rapid growth (38% higher than normal), February′s extent remained well below average for the month. Instead of measuring near 15.64 million sq. km., February 2013′s average extent was only 14.66 million sq. km., a 980,000 sq. km. difference! The Arctic likely reached its maximum annual extent about 10 days ago. In terms of annual maximum values, 2013′s 15.13 million sq. km. was 733,000 lower than normal.February’s relatively high rate of ice formation for February related to the lack of existing sea ice at the beginning of the month. Without ice already in the Ocean, new ice formed as winter continued.
Barents Sea (Atlantic side) ice finally edged toward its climatological normal value during the month after remaining low this winter, as it did in the past 10 winters. Kara Sea (Atlantic side) ice recovered from low extent the past couple of months, which is different from February 2012′s conditions. The Bering Sea (Pacific side), which saw ice extent growth due to anomalous northerly winds in 2011-2012, saw similar conditions in December 2012 through February 2013. This caused anomalously high ice extent in the Bering Sea again this winter. As it did previously this winter, a negative phase of the Arctic Oscillation allowed cold Arctic air to move far southward and brought warmer than normal air to move north over parts of the Arctic. The AO’s tendency toward its negative phase in recent winters is related to the lack of sea ice over the Arctic Ocean in September each fall.
In terms of climatological trends, Arctic sea ice extent in February has decreased by 2.9% per decade, the lowest of any calendar month. This rate is closest to zero in the late winter/early 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 (much 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 (e.g., 2011) – 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 February 11, 2013:
As is normal for this time of year, there is not a large difference between these two graphics. Any differences are primarily due to storm systems’ presence that push ice around, or the lack thereof. The lack of sea ice in the Barents Sea (north of Europe) 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 and then out into the Atlantic. The sea ice on the Atlantic side would be among the first that currents transport and then melt during the spring. With sea ice missing on the Atlantic side, currents will more easily transport Arctic sea ice to southern latitudes where it melts.
Many people questioned the overall health of the Arctic ice pack earlier this month when images (like the one below) and video documented extensive cracks in the ice in the Chukchi and Beaufort Seas. A fellow blogger (and new author!) emailed me about this phenomenon and I wrote that I would blog my thoughts on the topic. As Andrew Freedman wrote, “According to the National Snow and Ice Data Center (NSIDC) in Boulder, Colo., this fracturing event appears to be related to a storm that passed over the North Pole on Feb. 8, 2013, creating strong off-shore ice motion. The event is unusual but not unheard of, as similar patterns were seen in early 2011 and 2008. However, the NSIDC said the fracturing this time is more extensive.” The worry is the extent and size of the cracks and leads as well as the early calendar date at which they are all appearing – up to weeks before normal.
I found this article on the topic and agree with Greg Laden, the author. The cracks and leads might be a big deal or they might not. We will have to wait until the minimum sea ice extent occurs in September before we issue judgment. The scientifically sound course of action would be to wait until early cracks appeared in multiple seasons and then see what the range of response later in the year is. For all we know, the cracks could allow for even more ice to form in March than normal and delay the onset of melting. It strikes me as scientifically unsound and even irresponsible to conjecture about the existence and effect of processes, which we do not understand well. If scientists crow about upcoming devastating Arctic sea ice loss this year and reality doesn’t conform to their wishes, how much credibility with the public do they engender? I think observers should stay patient and discuss the phenomena and effects we do understand – there is plenty of material with which to work!
Figure 3 – NOAA AVHRR infrared picture of Arctic sea ice on 20130312.
The following graph of Arctic ice volume from the end of February demonstrates:
Figure 4 – PIOMAS Arctic sea ice volume time series through February 2013.
As the graph shows, volume (length*width*height) hit another record minimum in June 2012. Moreover, the volume remains far from normal since it just returned to the -2 standard deviation envelope (light gray). 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 the Powerball 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 February’s areal extent time series data:
Figure 5 – NSIDC Arctic sea ice extent time series through late March 2013 compared with last five years’ data and climatological norm (dark gray line) and standard deviation envelope (light gray).
As you can see, this year’s extent (light blue cuve) grew more rapidly in December than February. This graph also shows that this year’s extent remained at historically low levels through the winter, well below average values (thick gray curve), just as it did in the previous five winters, which are also shown on this graph. In this month’s version, NSIDC also plotted the previous four years’ data (2008 through 2012). You can also see what happened to conditions during late March and early April last spring (dark green curve). A late season freeze surge occurred, which delayed the date of maximum extent by a number of weeks. Last year’s surge has no bearing on what might happen over the next couple of weeks this year. Weather conditions and some low-frequency climate oscillations (AO) are different this year and have more bearing on ice conditions than last year’s date of maximum extent.
Antarctic Pictures and Graphs
Here is a satellite representation of Antarctic sea ice conditions from February 11, 2013:
Ice growth is easily visible around the continent. There is more Antarctic sea ice today than there normally is on this date in the year. The reason for this is the extra ice in the Weddell Sea (east of the Antarctic Peninsula that juts up toward South America). This ice exists this austral summer due to an anomalous atmospheric circulation pattern: persistent high pressure west of the Weddell sea pushed sea ice north. The same winds that pushed the sea ice north also moved cold Antarctic air over the Sea, which has kept ice melt rate well below normal. A similar mechanism helped sea ice form in the Bering Sea so far this winter. Where did the anomalous winds come from? We can again point to a climatic relationship.
The difference between the noticeable and significant 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. The vortex and associated anomalous high pressure centers kept ice and cold air over places such as the Weddell Sea this year.
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). The strong Antarctic polar vortex will likely weaken back to a more normal state and anomalous high pressure centers that keep ice flowing into the ocean will not form as often. 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 Greenland ice sheet melt. Were we to face a 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 through mid-March:
Given the lack of climate policy development to date, Arctic conditions will likely continue to deteriorate for the foreseeable future. The Arctic Ocean will soak up additional energy (heat) from the Sun due to lack of reflective sea ice. Additional energy in the climate system creates cascading and nonlinear effects throughout the system. For instance, excess energy pushes the Arctic Oscillation to a more negative phase, which allows anomalously cold air to pour south over Northern Hemisphere land masses while warm air moves over the Arctic during the winter. This in turn impacts weather patterns throughout the year across the mid-latitudes.
More worrisome for long-term concerns is the heat that impacts land-based ice. As glaciers and ice sheets melt, sea-level rise occurs. Beyond the increasing rate of sea-level rise due to thermal expansion (excess energy, see above), storms have more water to push onshore as they move along coastlines. We can continue to react to these developments as we’ve mostly done so far and allocate billions of dollars in relief funds because of all the human infrastructure lining our coasts. Or we can be proactive, minimize future global effects, and reduce societal costs. The choice remains ours.
Errata
Here are my State of Polar Sea Ice posts from February and January 2013. For further comparison, here is my State of Polar Sea Ice post from March 2012.
Update
I meant to include the following two graphs in this post because of the historical nature they represent.
The difference between these two graphics is obvious since they were taken near the time of minimum area (2012) and maximum area (2013). In terms of magnitude, the freeze season of 2012-2013 produced the highest amount of frozen ice area in the modern record (11.168 million sq. km.). The value of ice area last September was the lowest on record and the value of ice area earlier this month was the highest in four years. March’s area value occurred because of the factors I discussed above that boil down to this: the relative lack of thick ice in recent winters permitted rapid ice growth, albeit thin ice that melts quickly the following year. In addition to new record low area values in the future, significant oscillations from minimum to maximum and back again are likely to occur in the future as well. This does not contradict climate change; it is a manifestation of climate change. I hope write more about this topic soon, but countries are reconstructing international policy (military and economic) as a result of the changes seen in the Arctic. Those policy shifts will have societal repercussions, which I venture say few people realize today.
If you have had any exposure to this subject, you probably already have your mind made up about my title. As I’ve gained exposure, via multiple disciplines, I’ve changed my mind. And that allows me to look at climate reporting in new ways. Take this article and interview for instance. It’s meta-related, masked by the climate’s relationship to extreme weather. There are thousands of examples of conservatives ignoring science when it suits them. Doing so actually has more to do with conservatives operating from their value system. Are there similar examples of others ignoring science when it similarly suits them? I think it would be foolhardy to assume otherwise. Here is what I think about this article.
First, the mask: climate-extreme weather. There is no documented causal relationship between the two. In fact, the number of identified causal relationships between climate change and anything is still relatively small. There is a strong temperature signal. There is a growing ocean acidification signal. The sea level change signal is small but present and growing. How about precipitation? Nothing definitive. How about snowstorms? Nothing definitive.
But those signals are small against much stronger climate signals. Would something like drought or hurricanes or floods or tornadoes exhibit a stronger signal. In a word, no. There simply is not a detectable climate and extreme weather link today. That is not to say a future signal will not exist – there very well might be. But as of today, there is not. What science backs up that claim? The 2008 U.S. Climate Change Science Program’s Synthesis Report for starters (p.42; 2.2.2.1):
When averaged across the entire United States (Figure 2.6), there is no clear tendency for a trend based on the PDSI. Similarly, long-term trends (1925-2003) of hydrologic droughts based on model derived soil moisture and runoff show that droughts have, for the most part, become shorter, less frequent, and cover a smaller portion of the U. S. over the last century (Andreadis and Lettenmaier, 2006).
There is not enough evidence at present to suggest high confidence in observed trends in dryness due to lack of direct observations, some geographical inconsistencies in the trends, and some dependencies of inferred trends on the index choice. There is medium confidence that since the 1950s some regions of the world have experienced more intense and longer droughts (e.g., southern Europe, west Africa) but also opposite trends exist in other regions (e.g., central North America, northwestern Australia).
One big impediment to our extreme event trend ascertainment is our basic inability to monitor events in the first place. But based on the observations made, there is, in the IPCC’s own language, only medium confidence that droughts in some areas of the world are increasing in severity while decreasing in other places. Is climate change increasing extreme events? Not droughts – not yet.
What about storms like Sandy or Katrina (note: the former was a tropical system that changed to an extratropical system at landfall while the latter was a full-fledged hurricane at landfall)? There is at this time no global trend in hurricane frequency or intensity that demonstrates a clear causal relationship to climate change. There are indexes that a few scientists have developed to examine the data in different ways with differing results, but they require fairly complex methodologies to calculate. If I created my own index that demonstrated a relationship between the type of food I ate and climate change, does one cause the other? Certainly not directly. The hurricane-climate change relationship should exhibit a detectable signal in 50 more years or so. Until then, scientists cannot confidently say the data supports such a relationship. Extratropical storms increased in strength a little over the past century, although the locations of increase are limited. Their frequency has not increased.
Quickly, the same thing holds for floods and tornadoes. Datasets are simply too limited in space and time to currently identify a robust relationship.
As I wrote above, there are clear signals that we have already detected. The effects of those signals are mostly well-known, although some surprises are certainly in store for the planet. Extreme weather is not one of those signals. At least, not yet. If people are concerned about the level of inaction taken on climate change to date, it is folly to chase down or exaggerate signals that do not yet exist. If arguments based on signals detected are not enough to propel action, then we need to address their sets of values and how we communicate them. Fear-mongering and purposeful ignorance of science are not adequate substitutes.
Finally, I question the following from the article:
“I quote the climate skeptics or deniers — whatever term you prefer — when they’re relevant. So when I’m doing a piece about the science itself and what the latest scientific findings are, especially if that’s a short piece, I don’t necessarily feel obliged to quote the climate skeptics the same way that if you were doing a story about evolution, a New York Times reporter wouldn’t feel obliged to call up a creationist and ask them what they think. On the other hand, the climate skeptics are politically relevant at this point in American history [in a way that] the creationists are not, for example. So we have a fair chunk of the Congress … that sees political traction right now in questioning climate science or purporting not to believe it, so in a political story or in a longer story, I usually do give some amount of space to the climate skeptics.”
This quote comes from Justin Gillis, who writes about climate change for The New York Times. Does any of the above evidence make it into his interview with NPR? Here is my question: is Mr. Gillis a climate change writer or a politics writer? Scientific climate change writers should focus on the science. If Mr. Gillis wants to be a political climate change writer, he and the NYT owe it to their readers to make that distinction clear. Especially when double standards are applied to a different type of science writing. I would argue that creationists have a considerable amount of political traction right now also. I do not agree with their viewpoint, but if Mr. Gillis and the NYT want to write comparison pieces and not news pieces, I do not see why that effort should stop at climate change.
Energy intensity, or the amount of energy we use to create one dollar of GDP, has plummeted 58 percent between 1949 and 2011. Even more impressive is the 66 percent decrease in carbon intensity, or the amount of carbon emitted per real dollar of GDP.
The data are what the data are. This comment follows the data:
These improvements are what greens miss when they call for Americans to make painful, costly cutbacks on energy usage.
Let’s take another look at that data, now that we know the bias of the author. There are 62 years in the data cited. That means there was a 0.94% annual decrease in energy intensity. The good news is there was a decrease. We generated the same GDP dollar for less energy, as we expect in an advanced society with research and innovation. Similarly, there was a 1.06% reduction in carbon intensity. This value is important for energy and climate policy. The amount of carbon required for every GDP dollar fell over the past 62 years. Again, this is a good thing generally speaking. Technological efficiency permeated the economy over that time, which reduced the amount of carbon we emitted.
Now an important question: What caused this decrease? Was it emission reductions? No, US emissions have increased since 1950, with only a couple of periods when emission values didn’t increase every year. The US emitted just over 600 million metric tons (MMT) of carbon in 1950 and over 1500MMT in 2011. If carbon intensity is a measure of carbon per unit GDP, then the denominator increased faster than the numerator (GDP rather than carbon), in order for the ratio to decline over time. In 1950, the US real GDP was $2 trillion; in 2011, it was $13 trillion. Indeed, GDP increased faster than carbon emissions over the past 60 years.
What magnitude carbon intensity decrease is necessary to achieve carbon concentration reductions? First of all, carbon emissions have to decrease. Granted this has to occur globally, but let’s keep our focus on the US since we can actually control those emissions. Something between 3% and 4% annual decrease would do the trick. That is 3 to 4 times the historical rate! Let’s go back to the ratio: what has to change to achieve this decrease? It’s one of two things: carbon emissions or GDP. If GDP increases at the same rate it has historically, carbon emissions would have to decrease in value. If carbon emissions increased at the same rate they have historically, GDP would have to triple or quadruple in value. The former case is more likely because while we want GDP to grow as much as possible, tripling or quadrupling the rate of GDP growth won’t happen.
So our goal should be to decrease carbon emissions. If we can simultaneously increase GDP along the way, so much the better. We obviously should not look at “solutions” that decrease GDP. Walter Russell is unfortunately partially correct when he says that some greens miss part of reality. They place too much focus on decreasing emissions regardless of the consequences. In the real world, people still have to eat and pay for the mortgage. Walter does miss his own share of reality however. These graphs do not indicate a wildly efficient economy. We should not break out into celebration because of the graphs. We should instead examine them soberly and then determine what our goals should be. Do we want to decrease emissions and concentrations and if so to what level? Those goals will help us establish the requisite policies to achieve them. I for one do not think we are decarbonizing nearly fast enough and I think we can decarbonize faster via some common sense policies.
According to the Drought Monitor, drought conditions improved recently across some of the US. As of Mar. 12, 2013, 51.4% of the contiguous US is experiencing moderate or worse drought (D1-D4). That is the lowest percentage in a number of months. The percentage area experiencing extreme to exceptional drought increased from 17.7% to 16.5% in the last month. Percentage areas experiencing drought across the West stayed mostly the same while snowpack generally increased. Drought across the Southwest decreased slightly and rain from storms improved drought conditions in the Southeast.
My previous post preceded a major winter storm that affected much of the US. In some places in the High Plains and Midwest, 12″ or more of snow fell. With relatively high liquid water equivalency, this snow represented ~1″ of water precipitation. Unfortunately, these same areas required 2-4″ of rain to break their long-term drought. In other words, while welcome, recent snows have not substantially reduced drought severity affecting the middle of the nation, as the following map shows.
Figure 1 – US Drought Monitor map of drought conditions as of the 12th of March.
If we focus in on the West, we can see recent shifts in drought categories:
Figure 2 – US Drought Monitor map of drought conditions in Western US as of the 12th of March.
Some small relief is evident in the past couple of weeks, including some changes in the mountains as storms recently dumped snow across the region. Mountainous areas and river basins will have to wait until spring for snowmelt to significantly alleviate drought conditions. As you can probably tell, this is a large area experiencing abnormally dry conditions for almost a year now.
Here are conditions for Colorado:
Figure 3 – US Drought Monitor map of drought conditions in Colorado as of the 12th of March.
Drought conditions improved somewhat across the southwestern portion of the state in the past couple of weeks. The percentage area that is experiencing less than Severe drought conditions continues to track downward, which is a good sign. Unfortunately, Exceptional drought conditions continued their hold over the eastern plains.
Here are conditions for the High Plains states:
Figure 4 – US Drought Monitor map of drought conditions in the High Plains as of the 12th of March.
Again, even with large snowfalls in the past month, little drought relief is evident across this region. What these states need are frequent soaking rains in the spring and summer to alleviate their long-term drought. Agriculture certainly could use that relief this year.
And finally the area that experienced the most relief in the past month, the Southeast:
Figure 5 – US Drought Monitor map of drought conditions in the Southeast as of the 12th of March.
The shifts in the numbers in the table tell a good story. Frequent storms tracked over this region recently, which helped bust the worst conditions (Severe and worse). Look at the ‘None’ category now versus three months ago: the percent area doubled! Now the rains need to continue through the rest of the year.
US drought conditions are related to Pacific and Atlantic sea surface temperature conditions. Different natural oscillation phases preferentially condition environments for drought. Droughts in the West tend to occur during the cool phases of the Interdecadal Pacific Oscillation and the El Nino-Southern Oscillation, for instance. Beyond that, drought controls remain a significant unknown. Population growth in the West in the 21st century means scientists and policymakers need to better understand what conditions are likeliest to generate multidecadal droughts, as have occurred in the past.
As drought affects regions differentially, their policy responses vary. A growing number of water utilities recognize the need to be proactive with respect to drought impacts. The last thing they want is their reliability to suffer. Americans are privileged in that clean, fresh water flows when they turn their tap. Crops continue to show up at their local stores despite terrible conditions in many areas of their own nation. Power utilities continue to provide hydroelectric-generated energy.
That last point will change in a warming and drying future. Regulations that limit the temperature of water discharged by power plants exist. Warmer conditions include warmer water today than what existed 30 years ago. Warmer water into a plant either mean warmer water out or a longer time spent in the plant, which reduces the amount of energy the plant can produce. We can continue to generate the same amount of power if we are willing to sacrifice ecosystems which depend on a very narrow range of water temperatures. As with other facets of climate change, technological innovation can help increase plant efficiency.
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.
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.
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.
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:
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.
Climate change skeptics used the recent slowdown in observed surface warming to claim that 20th century warming was temporary and that the Earth would return to lower average annual temperatures. They offered up many potential explanations for the slowdown, none of which make physical sense. The Sun’s 11-year cycle (often used to explain away warming), a primary argument brought forth, is not the reason: this cycle’s solar maximum is near at hand, yet warming has slowed down recently.
Recently accepted research points to a viable physical explanation. In addition to oceanic transport of heat to the deep ocean and recent La Nina events, sulfuric emissions from small and mid-sized volcanoes entered the lower stratosphere and reflected more incoming solar radiation than normal. This research separated the effect of natural sulfur emissions from anthropogenic emissions, using a model, to determine the former had a much larger influence than thought. Aerosol optical depth (AOD) is a calculated metric used to represent how opaque or transparent the atmosphere is to different radiation wavelengths. The layer between 20 and 30 km increased 4-10% per year since 2000, which is a significant change from normal conditions – significant enough to have effects on Earth’s climate.
Here is one of the paper’s graphical results:
Figure 1. Observed and modeled time series of stratospheric AOD from three latitude bands. Satellite observations are represented by the black line. Base-line model runs are in green. Model runs with the increase in anthropogenic emissions from China and India are in blue. The dashed blue line depicts a model run with 10x the actual increase in anthropogenic emissions. The model run with volcanic emissions is in red. The black diamonds and initials along the bottom of the plot represent the volcanic eruptions that were included in the model run. (Source: Neely paper; subs. req’d.)
As the caption says, satellite measurements are denoted by the thick black curve. Note the large increase in AOD (higher opacity) over the tropics in the mid-2000s (b) and the large AOD increase over the northern mid-latitudes in the late-2000s (a). While not a perfect fit to the observations, the model run with volcanic eruptions (red curve) does the best job of explaining the origin of the SO2. Individual eruptions are indicated by black diamonds on the bottom of each sub-plot. The effects of volcanic eruptions on climate are, in a general sense, well-known. Injections of SO2 into the stratosphere reflects sunlight, which reduces the amount of energy entering the Earth’s climate system. The difference between one large-scale eruption (e.g. Pinatubo in 1991) or many mid-sized eruptions in a short time-period (see above) is not large as far as the climate is concerned.
This could be good news as far as the climate is concerned, at least in the shorth-term. If incoming energy were reflected back into space instead of being stored in the system, we can physically explain the observed temperature trend slowdown (see Figure 2) and treat the slowdown as real instead of waiting for that energy to transfer from the oceans to the atmosphere, for example.
There is also bad news however. From the study (emphasis mine):
The significant portion of the radiative forcing due to increases in stratospheric aerosol from 2000 to 2010, interpreted as a mechanism of global cooling [Solomon et al., 2011], may now be completely attributed to volcanic sources and should not be considered a trend. Rather, the stratospheric aerosol layer should be treated as a natural source of radiative forcing that is continuously perturbed by volcanic injections of a range of sizes, and potentially other sources such as large fires.
Figure 2. Global mean surface temperature anomaly maps and 12-month running mean time series through January 2013 from NASA.
We can see from the 12-month running mean time series (lower-right in Figure 2) that NASA’s temperature index increased more slowly during the latter part of the 2000s than the 1990s. Neely et al. suggest that there is no physical reason to conclude that slowdown is a trend of opposite sign than that seen throughout the 20th century. In other words, once the SO2 precipitates from the stratosphere, as it eventually will, the background warming trend will re-establish itself. Indeed, future warming will likely be stronger than past warming because CO2 concentrations have not decreased in the past ten years. To the contrary, they have increased at a faster rate than before. Greenhouse gases have simply had less incoming radiation to absorb than they did 10 years ago due to the recent presence of SO2 in the stratosphere.
Neely’s coauthor Brian Toon had this to say:
Toon of CU-Boulder’s Department of Atmospheric and Oceanic Sciences. “But overall these eruptions are not going to counter the greenhouse effect. Emissions of volcanic gases go up and down, helping to cool or heat the planet, while greenhouse gas emissions from human activity just continue to go up.”
This situation provides a good example of another aspect of climate policy. I wrote about geoengineering earlier this year as part of a Polar Sea Ice post (much more discussion took place here). One proposed mechanism to reduce the impacts of climate change is human injection of SO2 into the stratosphere, which would mimic natural volcanic effects. If we implemented such a strategy without simultaneously reducing atmospheric greenhouse gas concentrations, then abruptly stopped the injection (due to lack of funds or international controversy), the resulting warming signal would be higher post-injection than pre-injection. The result would be unprecedented due to the large warming signal such a halt would introduce to the climate system.
In one more respect then, policymakers have wasted the past decade. Instead of developing and implementing climate mitigation policies, international inaction continued. Once the atmosphere removes the SO2, the climate signal will be stronger than before. We cannot and should not rely on future volcanic SO2 emissions to mitigate our GHG emissions. The lack of robust policies is a choice, but it is not a wise long-term choice.
According to data released by NASA and NOAA last week, January was the 6th and 9th warmest January’s (respectively) globally on record. Here are the data for NASA’s analysis; here are NOAA data and report. The two agencies have slightly different analysis techniques, which in this case resulted in not only different temperature anomaly values but somewhat different rankings as well. The two techniques provide a check on one another and confidence for us.
The details:
January’s global average temperatures were 0.61°C (1.098°F) above normal (1951-1980), according to NASA, as the following graphic shows. The warmest regions on Earth coincide with the locations where climate models have been projecting the most warmth will occur: high latitudes (especially within the Arctic Circle). The past three months have a +0.58°C temperature anomaly. And the latest 12-month period (Feb 2012 – Jan 2013) had a +0.58°C temperature anomaly. The time series graph in the lower-right quadrant shows NASA’s 12-month running mean temperature index. The recent downturn (2010-2012) is largely due to the latest La Niña event (see below for more) that ended early last summer. Since then, ENSO conditions returned to a neutral state (neither La Niña nor El Niñ0). Therefore, as previous anomalously cool months fall off the back of the running mean, and barring another La Niña, the 12-month temperature trace should track upward again in 2013.
Figure 1. Global mean surface temperature anomaly maps and 12-month running mean time series through January 2013 from NASA.
According to NOAA, January’s global average temperatures were 0.54°C (0.97°F) above the 20th century mean of 14.0°C (57.2°F). NOAA’s global temperature anomaly map for January (duplicated below) shows where conditions were warmer than average during the month.
The two different analyses’ importance is also shown by the preceding two figures. Despite differences in specific global temperature anomalies, both analyses picked up on the same temperature patterns and their relative strength.
The very warm conditions found over Greenland and Alaska are a concern. These areas were warmer than average during more months in recent history than not. Additionally, Australia was much warmer than usual. Indeed, Australia’s January average temperature was the highest on record: +2.28°C (4.10°F!) above the 1961–1990 average, besting the previous record set in 1932 by 0.11°C (0.20°F). In contrast to 2012, Siberian temperatures were cooler than normal. This is likely a temporary, seasonal effect. Long-term temperatures over northern Siberia continue to rise at among the fastest rate for any region on Earth.
These observations are also worrisome for the following reason: the globe came out of a moderate La Niña event in the first half of the year. During the second half of the year, we remained in a ENSO-neutral state (neither El Niño nor La Niña):
The last La Niña event hit its highest (most negative) magnitude more than once between November 2011 and February 2012. Since then, tropical Pacific sea-surface temperatures peaked at +0.8 (y-axis) in September 2012. You can see the effect on global temperatures that the last La Niña had via this NASA time series. Both the sea surface temperature and land surface temperature time series decreased from 2010 (when the globe reached record warmth) to 2012. So a natural, low-frequency climate oscillation affected the globe’s temperatures during the past couple of years. Underlying that oscillation is the background warming caused by humans. And yet temperatures were still in the top-10 warmest for a calendar year (2012) and individual months, including January 2013, in recorded history.
Skeptics have pointed out that warming has “stopped” or “slowed considerably” in recent years, which they hope will introduce confusion to the public on this topic. What is likely going on is quite different: since an energy imbalance exists (less outgoing energy than incoming energy) and the surface temperature rise has seemingly stalled, the excess energy is going somewhere. That somewhere is likely the oceans, and specifically the deep ocean. Before we all cheer about this (since few people want surface temperatures to continue to rise quickly), consider the implications. If you add heat to a material, it expands. The ocean is no different; sea-levels are rising because of heat added to it in the past. The heat that has entered in recent years won’t manifest as sea-level rise for some time, but it will happen. Moreover, when the heated ocean comes back up to the surface, that heat will then be released to the atmosphere, which will raise surface temperatures as well as additional water vapor. Thus, the immediate warming rate might have slowed down, but we have locked in future warming (higher future warming rate).
In a previous post on global temperatures, I pointed a few things out and asked some questions. The Conference of Parties summit produced no meaningful climate action (November 2012). Countries agreed to have something on paper by 2015 and enacted by 2020. If everything goes as planned (a huge assumption given the lack of historical progress), significant carbon reductions wouldn’t occur until later in the 2020s – too late to ensure <2°C warming by 2100. If, as is much more likely, everything doesn’t go as planned, reductions wouldn’t occur until later than the 2020s. Additional meetings are scheduled for this year, but I maintain my expectation that nothing meaningful will come from them. The international process is ill-equipped to handle all the legitimate interest groups in one fell swoop.
Instead, actions that start locally and grow with time are more likely to address emissions and eventual warming and other climate change effects. People started small-scale activities in cities around the world in recent years. There are also regional and international carbon markets. While most markets were poorly designed, lessons learned from the first generation can be used to make future generation markets more effective. As these small-scale efforts grow and their effects combine, larger bodies will need to address differences between them so that they work for larger populations and markets.
Paying for recovery from seemingly localized severe weather and climate events is and always will be more expensive than paying to increase resilience from those events. As drought continues to impact US agriculture, as Arctic ice continues to melt to new record lows, as storms come ashore and impacts communities that are not prepared for today’s high-risk events (due mostly to poor zoning and destruction of natural protections), economic costs will accumulate in this and in future decades. It is up to us how many costs we subject ourselves to. As President Obama begins his second term with climate change “a priority”, he tosses aside the most effective tool available and most recommended by economists: a carbon tax. Every other policy tool will be less effective than a Pigouvian tax at minimizing the actions that cause future economic harm. It is up to the citizens of this country, and others, to take the lead on this topic. We have to demand common sense actions that will actually make a difference. But be forewarned: even if we take action today, we will still see more warmest La Niña years, more warmest El Niño years, more drought, higher sea levels, increased ocean acidification, more plant stress, and more ecosystem stress. The biggest difference between efforts in the 1980s and 1990s to scrub sulfur and CFC emissions and future efforts to reduce CO2 emissions is this: the first two yielded an almost immediate result while it will take decades before CO2 emission reductions produce tangible results humans can see.
