There is little doubt among archaeologists that the Younger Dryas, a cold snap following the initial retreat of Ice Age conditions some 11,000 years ago, had a major impact on human history. It seems that humans are highly motivated to return the impact to the Younger Dryas. Two times in recent years, evidence of an impact, a celestial object whacking into the Earth, has been suggested as the cause of the famous climatic “two step.” As sexy as impacts are, however, it is very unlikely that the Younger Dryas was caused by one. Continue reading The latest newly discovered meteor impact that did not cause the Younger Dryas→
Voters seem to have liked many candidates endorsed by environmental organizations, or who had good climate change related policies. But, they seem to have rejected ballot initiatives, in Colorado, Arizona, and Washington, that would have moved us closer to the necessary energy transition. Continue reading Did Voters Vote Climate? Yes And No→
I have been discussing on this blog for a few years not the problem of quasi-resonant amplification (QRA) of the jet stream. Let me quickly review what that is, then tell you about the new research.
The Earth is encircled by giant twisting donuts of air. The two main donuts lie side by side along the equator. Air warmed at the point where the sun is strongest (a climatological equator that moves north and south with the seasons) rises. It traverses, at altitude, either north or south, towards the polls, then drops and then circles back towards the equator. This drives wetness at the equator as moist air hits cold air aloft and thunderstorms are everywhere.
These primary giant twisting donuts, called Hadley Cells, set up a second set of twisting donuts to the north and south. These donuts, called mid-latitude cells, tend to cause a dry zone to form. Look at a map of the planet, and you can trace the dry zone across the northern hemisphere from the deserts of Central Asia, to the deserts of the US Southwest. In the south, the deserts of Namibia, Botswana and South Africa line up with dry regions of South America and, pretty much all of Australia.
There is a third cell, the Polar cell, north and south of the mid latitude cells.
These cells, as they move around the spinning earth, are the trade winds. Near junctures of the cells, at latitude, air molecules face an interesting mathematical problem. Air pressure, temperature, cell-driven winds, and all the various factors set up a situation where those air molecules sitting between the upper parts of the cells are supposed to be somewhere where they are not, pretty much all the time. In order to solve that problem, the air has to move very rapidly in one direction. This is a bit like nature abhorring a vacuum, large scale. That rapidly moving river of air is the jet stream.
A combination of trade wind effects and the jet stream tends to move storm systems around the planet in the mid latitudes. Under pre-climate change conditions, a low pressure system might ride along just south of the Jet Stream, moving across the planet at a few tens of km an hour, bringing rain followed by fair weather. But if the jet stream either slows or changes direction somewhat, that conveyor belt effect can get kinked up, and the low pressure system can sit in a giant meteorological kink, causing a large region to experience wet conditions for days or weeks at a time. Meanwhile, on the other side of the jet stream, in the counter-kink that a curved jet stream might cause, you can get a stalled high pressure system bringing dry conditions for longer than normal, causing what meteorologist Paul Douglas calls a “flash drought.”
Go back to the beginning a second. This entire process is controlled by the global process of heat accumulated in abundance at the equator moving to the north and south poles. But in recent years, the arctic has warmed considerably. Lack of snow cover in northern Canada and Siberia, loss of sea ice, and, probably, darkening of glacial ice in Greenland, combine to cause the Arctic to warm to a much greater degree than the rest of the planet.
This is a little like putting your refrigerator too close to the wall and building a cabinet around it without proper ventilation. The heat pump that runs your refrigerator will stop working. The behavior of the giant twisting donuts and the jet streams changes.
What occurs is this: The jet stream gets wavy, and that waviness can form a standing wave, like a swirl you see in a running brook that sits in one place because of an underwater obstruction like a rock or log. The wave, in a sense, resonates with the circumference of the earth, so you get a regular number of waves around the planet, and they tend to move only very slowly, or not at all, for months at a time.
There are two phenomena that have caused the plethora of wild and wicked weather we have been experiencing across the globe for the last five or six years. One is the increase in strength and possibly frequency of various storm systems as a nearly direct effect of warming. The other is this QRA system causing major weather patterns to pan out abnormally.
These two problems can interrelate, by the way, but that is a subject of a different essay, perhaps.
The result of quasi-resonant waves? The California drought, massive multi day rainfall events in Calgary, Boulder, Minnesota, China, Japan, Mediterranean Europe, and on and on and on.
Two questions arise from the research showing this effect. One: is it real, is there really a QRA effect? Two: will this persist, get worse, or get better, over time?
The answer to the first question has been getting more and more solid with the publication of research paper after research paper. There isn’t any longer a doubt, in my view, that this phenomenon is for real and seroius. The second question is harder. The paper that came out today on this topic says that the degree of extra warming in the Arctic is probably the biggest factor affecting the future of QRA effects. The research also suggest that it could get worse and it could persist. But there still is some uncertainty.
We find that the incidence of QRA events would likely continue to increase at the same rate it has in recent decades if we continue to simply add carbon dioxide to the atmosphere. But there’s a catch: The future emissions scenarios used in making future climate projections must also account for factors other than greenhouse gases. Historically, for example, the use of old coal technology that predates the clean air acts produced sulphur dioxide gas which escapes into the atmosphere where it reacts with other atmospheric constituents to form what are known as aerosols.
These aerosols caused acid rain and other environmental problems in the U.S. before factories in the 1970s were required to install “scrubbers” to remove the sulphur dioxide before it leaves factory smokestacks. These aerosols also reflect incoming sunlight and so have a cooling effect on the surface in the industrial middle-latitudes where they are produced. Some countries, like China, are still engaged in the older, dirtier-form of coal burning. If we continue with business-as-usual burning of fossil fuels, but countries like China transition to more modern “cleaner” coal burning to avoid air pollution problems, we are likely to see a substantial drop in aerosols over the next half century. Such an assumption is made in the Intergovernmental Panel on Climate Change (IPCC)’s “RCP 8.5” scenario—basically, a “business as usual” future emissions scenario which results in more than a tripling of carbon dioxide concentrations relative to pre-industrial levels (280 parts per million) and roughly 4-5C (7-9F) of planetary warming by the end of the century.
As a result, the projected disappearance of cooling aerosols in the decades ahead produces an especially large amount of warming in middle-latitudes in summer (when there is the most incoming sunlight to begin with, and, thus, the most sunlight to reflect back to space). Averaged across the various IPCC climate models there is even more warming in mid-latitudes than in the Arctic—in other words, the opposite of Arctic Amplification i.e. Arctic De-amplification (see Figure below). Later in the century after the aerosols disappear greenhouse warming once again dominates and we again see an increase in QRA events.
Author Michael Mann notes, “Most stationary jet stream disturbances will dissipate over time. However, under certain circumstances the wave disturbance is effectively constrained by an atmospheric wave guide, something similar to the way a coaxial cable guides a television signal. Disturbances then cannot easily dissipate and very large amplitude swings in the jet stream north and south can remain in place as it rounds the globe.”
From the abstract of the original paper:
Persistent episodes of extreme weather in the Northern Hemisphere summer have been associated with high-amplitude quasi-stationary atmospheric Rossby waves, with zonal wave numbers 6 to 8 resulting from the phenomenon of quasi-resonant amplification (QRA). A fingerprint for the occurrence of QRA can be defined in terms of the zonally averaged surface temperature field. Examining state-of-the-art [Coupled Model Intercomparison Project Phase 5 (CMIP5)] climate model projections, we find that QRA events are likely to increase by ~50% this century under business-as-usual carbon emissions, but there is considerable variation among climate models. Some predict a near tripling of QRA events by the end of the century, while others predict a potential decrease. Models with amplified Arctic warming yield the most pronounced increase in QRA events. The projections are strongly dependent on assumptions regarding the nature of changes in radiative forcing associated with anthropogenic aerosols over the next century. One implication of our findings is that a reduction in midlatitude aerosol loading could actually lead to Arctic de-amplification this century, ameliorating potential increases in persistent extreme weather events.
Global warming is already upon us, but when was the last time you had a proper chat about it?? For Green Great Britain Week, ClimateAdam speaks to a climate communication expert (Steve) to take his conversation skills from amazing to brilliant.
Last month, deep in a 500-page environmental impact statement, the Trump administration made a startling assumption: On its current course, the planet will warm a disastrous 7 degrees by the end of this century.
A rise of 7 degrees Fahrenheit, or about 4 degrees Celsius, compared with preindustrial levels would be catastrophic, according to scientists. Many coral reefs would dissolve in increasingly acidic oceans. Parts of Manhattan and Miami would be underwater without costly coastal defenses. Extreme heat waves would routinely smother large parts of the globe.
But the administration did not offer this dire forecast, premised on the idea that the world will fail to cut its greenhouse gas emissions, as part of an argument to combat climate change. Just the opposite: The analysis assumes the planet’s fate is already sealed.
Climate activists and poets, Kathy Jetnil-Kijiner and Aka Niviana, travel to the latter’s home of Greenland to recite their collaborative poem, Rise, on a melting glacier that might threaten the former’s home nation of the Marshall Islands in the Pacific
It is never too soon to talk about human caused climate change in relation to hurricanes. This is a bed we made and we are now sleeping in it.
Rather than yammering on and on about how a warmer atmosphere is a damper, but also more evaporation-inducing (and thus drying), and energetic atmosphere, and about how warmer air going over warmer sea water produces more and bigger storms globally, and all that, I’ll point you to some resources below.
But first I want to address two misconceptions: 1) that you can never attribute to a particular storm the effects of climate change THIS IS FALSE and 2) that climate scientists believe that Atlantic hurricanes will become less and less of a problem with climate change THIS IS ALSO FALSE.
On the attribution. Let’s say there is a disease with a 50% mortality rate. But then a treatment is invented that reduces that to zero. We use the treatment widely and nobody dies of it any more. Then, you get the disease, are cured, and go on a public speaking tour in which you espouse the greatness of this cure.
But one night, while you are speaking in front of a large audience, someone stands up and says, “Hey, wait one darn minute there! You might have been one of the 50% that would have lived! You can’t say that this cure did ANYTHING. Faker!”
The audience, realizing that the cure does not actually work, stands up and walks out.
Was that fair? Was what just happened in this scenario a honest, thoughtful turn of events?
With climate change it is a little like that. People who want to deny the importance of climate change, including journalists still stuck in the false balance mode (if there are Senators in the Senate claiming that human caused global warming is a hoax, then we must consider that as equally likely as what all the world’s scientists are saying), pull the attribution rabbit out of the hat all the time. Since you can’t yada yada. Even some climate scientists used to say this because the were badly trained in what to say.
Indeed, the binary (cure/not cured) I gave you above is not really like climate change. The fact that ALL the sea surfaces in the tropics and sub tropics — every single square centimeter — are on average (and in fact most of the time, for most of the seconds of most of the days, all year) anomalously warm, all of the tropical weather systems are affected all of the time. Fail to understand that at your peril.
The second falsehood, that Atlantic hurricanes will become less of a problem, is perhaps even more pernicious. There once was a study that seemed to show that some of the climatic conditions that would attenuate tropical cyclones, denying them the chance to form into hurricanes, would become more common in the Atlantic. This is probably true. However, the climatic conditions that cause tropical storms to form and advance to hurricane stage are also increased — different effects — and these effects have the added bonus of causing hurricanes to form much more rapidly and sometimes (perhaps often) grow much larger and, by the way, exist farther north. Indeed, if Florence does reach Category 5 for a short time today or tomorrow, it will be the farthest north Cat 5 hurricane ever in the Atlantic.
Here’s the thing. We will see periods of time when hurricanes that might have formed, say, 20 years ago, won’t. But we will also see periods of time when more and bigger and worser hurricanes form. The actual average number of hurricanes in the Atlantic has not gone down, but rather, stayed fairly stable, over recent decades. The frequency of large and dangerous hurricanes globally has gone up, and that trend is probably observable in the Atlantic.
Point is, we are not seeing a decrease in Atlantic hurricane activity or impressiveness, and we are seeing records being broken with respect to time to formation, size, strength, etc.
Climate Signals has a page on Hurricane Florence. They point out that sea level rise and coastal storms are a significant coastal erosion threat. warmer waters make for more and bigger hurricanes, keeping the hurricanes big longer, and making them form faster. These hurricanes are wetter.
Indeed, we have replaced the term “Biblical Flooding” with “Harvey Size Flooding” since we no longer have to imagine it.
Here is a helpful video:
This graph showing the relationship between sea surface temperature and hurricane activity.
Steve Goddard, or as I like to call him, Dorothy (because Dorothy of the Wizard of Oz is his avatar, and I think he might live in Oz) is one of those science deniers who now and then produces a graphic that shows that global warming isn’t real. He is increasingly being ignored by even the ingenuous, but his latest attempt to deny reality has been slapped down so effectively by scientist and blogger Tamino that thought you should see it.
I’m just going to give you a little bit of the story, and then send you to Tamino’s excellent post.
First, here is Goddard’s graphic attempting to show that global warming is not real.
See how temperatures are going down? How can that be? Note that this is average maximum temperature over time, 1918-present, in the US.
Why 1918 (the data set goes back farther)? Why the US? Also, why is he using absolute temperatures instead of the usually used anomalies? Maybe he knows something we don’t know. Or, maybe he is counting on his audience not knowing some stuff that all the experts know.
Now look at this graph, produced by climate scientist Tamino.
That’s a silly graph, isn’t it. It appears to show the mean latitude of something over time. Of what? Of the stations used to estimate temperatures. How is this relevant to the present discussion?
And that is the United States, and that is because of Donald Trump. From WaPo:
The Trump administration on Thursday announced plans to freeze fuel-efficiency requirements for the nation’s cars and trucks through 2026 — a massive regulatory rollback likely to spur a legal battle with California and other states, as well as create potential upheaval in the nation’s automotive market.
The proposal represents an abrupt reversal of the findings that the government reached under President Barack Obama, when regulators argued that requiring more-fuel-efficient vehicles would improve public health, combat climate change and save consumers money without compromising safety.
Trump’s plan also undercuts California’s long-standing ability to set its own tailpipe restrictions, most recently in an effort to curb greenhouse-gas emissions.
What is the rational for this? There is only one. Hippie punching. He is showing his base that he has yet another way to make the liberals cry.
But guess what. The liberals will not cry. But they will fight.
My only remaining Republican friend, Paul Douglas, provided this information.
Considering the top 20 most destructive California fires from Cal Fire’s database, 6 of those have happened in the last 10 months.
The worse so far is the Tubbs Fire last October, and that was HUGE. Nearly 6,000 structures were burned, 22 people were killed. The sixth on the list is the Carr fire, with just under 1,500 structures burned and six killed as of this writing, but that fire is still burning.
I’ll just add this. There was a moment in time between about 2 and 3 years ago, when it was apparent to me and many others that fires were getting worse. But the data was just coming in. There were studies that stopped their data roughly a year or a year and a half earlier that showed no statistically convincing increase. The delay in data range is normal. You get your data, clean it up, then Reviewer three adds eight months to the publication process, etc. so most studies are one or maybe two years late. Anyway, I was being told over and over again that I was wrong whenever I talked about fires. Much of that came from those who were sufficiently in the game to pretend they were not denying climate change, but who chose to get into the contrarian game despite the huge moral cost of doing so.
Well, we were right. We told you so. Shame.
Eventually, of course, the wildfires will stop. Like the surgeons say, the bleeding always stops. Eventually. One way or another.