onsdag 3. juli 2019

Magnetic poles / Earth's magnetic field


While the Earth's magnetic axis is shifting somewhat, Earth's rotational axis shifts only a little bit, mostly in response to the mass redistribution of water around the Earth from land-based ice sheet losses. This is a normal response.

The net change in the position of the Earth's rotational axis is about 37 feet. The largest annual change is about 7 inches.

If you move over 37 feet, the climate doesn't change. It changes even less per year if you only move 7 inches.

https://www.jpl.nasa.gov/news/news.php?feature=6332&fbclid=IwAR30M6zx7MmHOFFnFRw8Lygr0WFv2TvbSZWKesUzxXFQ96MMZLdsLYbhSTc



The research paper itself is here:

https://advances.sciencemag.org/content/2/4/e1501693

https://news.nationalgeographic.com/2016/04/160408-climate-change-shifts-earth-poles-water-loss/?fbclid=IwAR0hFsJETBVWZFiMDK23FYggPPYCtiAW24V7jX_1BY_swBs404ds7SlCHno



Since air isn't ferrous, magnetic field polarity shifts are of little consequence to weather and climate.

________________________

While the Earth's magnetic field is weakening a bit and its magnetic axis is shifting somewhat, magnetic field polarity changes have no effects on climate on the timescale of human lifetimes because air isn’t ferrous. The effects on hand-held compasses are insignificant. For purposes of electronic navigation, changes in the position of the magnetic poles are constantly updated in navigational databases.

https://www.ncei.noaa.gov/news/tracking-changes-earth-magnetic-poles?fbclid=IwAR2a0pL9QVM81OF5yQpi5ljijpAiwVJ9BEYtnoi_S7obuW93fKm3tQJDEJw

https://www.ncei.noaa.gov/news/world-magnetic-model-out-cycle-release?fbclid=IwAR01FyhG-vozqBCwcN1IDfk5QUfd_1ygN3fOsRrvUn97_JMVSpgZAi6aXIQ

https://www.ncei.noaa.gov/news/world-magnetic-model-out-cycle-release?fbclid=IwAR01FyhG-vozqBCwcN1IDfk5QUfd_1ygN3fOsRrvUn97_JMVSpgZAi6aXIQ

https://www.ngdc.noaa.gov/geomag/faqgeom.shtml?fbclid=IwAR3hVbT8Z7hMNplhds-w-4VhUppqyyMBClWKkx6Lyzf6T8Ypiz7XbX00h-s

https://www.maritime-executive.com/article/position-of-magnetic-north-pole-officially-changed?fbclid=IwAR0KcNdgM1spcXnw6XHjpW3lRKcUzeNQ9kryLYREhOBgRXd4zuoFy-D9dJU

"The last time that Earth's poles flipped in a major reversal was about 780,000 years ago, in what scientists call the Brunhes-Matuyama reversal. The fossil record shows no drastic changes in plant or animal life. Deep ocean sediment cores from this period also indicate no changes in glacial activity, based on the amount of oxygen isotopes in the cores. This is also proof that a polarity reversal would not affect the rotation axis of Earth, as the planet's rotation axis tilt has a significant effect on climate and glaciation and any change would be evident in the glacial record."

And

"The science shows that magnetic pole reversal is – in terms of geologic time scales – a common occurrence that happens gradually over millennia. While the conditions that cause polarity reversals are not entirely predictable – the north pole's movement could subtly change direction, for instance – there is nothing in the millions of years of geologic record to suggest that any of the 2012 doomsday scenarios connected to a pole reversal should be taken seriously."

https://www.nasa.gov/topics/earth/features/2012-poleReversal.html?fbclid=IwAR2LY7WFUdQBTLnXw8hHjW1sKhf8nfg85tMXR4rqWXYwkmS6pzsMI0M1i64

https://www.livescience.com/18426-earth-magnetic-poles-flip.html?fbclid=IwAR0VuwKQLND8aI5hVA06DEibprJ-r6RdZ8hFjJVe2wIoenhfBY2YbIg0Cg4


"What would happen if the magnetic field of the Earth suddenly changed?

If the magnetic field of the Earth suddenly changed, and this DOES happen naturally every 250,000 years or so, the consequences would be fascinating. For life, we can see from the fossil record that the past field changes had no significant effect on living organisms. This is most curious because the field reversal ( North magnetic pole shifting to antarctica and the South magnetic pole shifting to the arctic region in the Northern Hemisphere) one might expect the field to go to zero strength for a century or so. This would let cosmic rays freely penetrate to the Earth's surface and cause mutations. This seems not to have had much effect in the past, so we probably don't really know what is going on during these field reversals. There have been a dozen of them over the last few million years, documented in the rock which has emerged and solidified along the mid-Atlantic Ridge where continental plates are slowly separating. These epochs form parallel bands all long the ridge where the rock has stored a fossilized image of the local orientation of the Earth's magnetic field for the last few million years.

Magnetic field wandering would let the aurora borealis occur at any latitude, but other than that there would be no noticeable effects other than changes in the amount of cosmic rays that penetrate to the ground. Even this effect is minimal because we can visit the Arctic and Antarctic and only receive a slight increase in cosmic rays. So long as the strength of the field remains high during this field wandering event, the effects should be pretty benign.



"one total bonus of having a weaker magnetic field is that auroras will be visible from much lower latitudes, so the nighttime skies will be even more epic"


(-technical, non-climate discussion-)


_____________________




















torsdag 13. juni 2019

Mid-century cooling in the 20th Century:explained.



Mid-century cooling in the 20th Century: skeptics point to it and ask about it. What's the real story?

As a preface, scientists have evaluated all natural forcings and factors capable of driving the Earth's climate to change and it is only when the anthropogenic forcing is included that the ongoing observed warming can be explained.

Natural vs Anthropogenic Climate Forcings, per the NCA4, Volume 2:

https://nca2018.globalchange.gov/img/figure/figure2_1.png
Digging into the question, early 20th Century warming (1910-1940) was about one-third caused by human activities. The rest of that was a combination of natural factors. Starting in the war years (1940) and continuing through the 1970s, sulfate aerosol emissions (which act to reflect incoming sunlight, cooling the Earth’s surface) combined with natural cooling held daytime temperatures flat, despite increasing CO2 and other GHG emissions from human activities. However, during this time nighttime low temperatures continued to increase, a hallmark confirmation of the combined effects of increases in GHG emissions from human activities coupled with sulfate aerosol emissions from industrial activities (the explosions during WW2 and the post-war reconstruction boom in industrial activities).

https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0555.1

https://www.osti.gov/biblio/15020102

https://www.tandfonline.com/doi/abs/10.3402/tellusa.v43i4.11944

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006GL028031

Looking at the temperature trends of both the Northern and Southern Hemispheres, if both CO2 and sulfate aerosol emissions were rising, we’d expect to see greater cooling in the Northern Hemisphere than in the Southern Hemisphere, which is exactly what we observe:


https://data.giss.nasa.gov/gistemp/graphs/graph_data/Hemispheric_Temperature_Change/graph.png

By the end of the 1970s, the cleaning of the air due to the passage of the Clean Air Act of 1970 (which limited sulfate aerosol emissions from industry), coupled with the significant increase in CO2 emissions from human activities combined to drive global surface temperatures upwards.

https://19january2017snapshot.epa.gov/clean-air-act-overview/clean-air-act-requirements-and-history_.html

Since 1980 alone, annual global CO2 emissions have doubled:

https://ourworldindata.org/co2-and-other-greenhouse-gas-emissions#co2-emissions-global-and-regional-trends

As a result, global temperatures spiked, with the rise ongoing still today, unabated:


“climate scientists have had a difficult time explaining exactly what caused a warming event in the early 20th century, between about 1910 and 1945. “[…] The new study, published in the Journal of Climate, tackles the discrepancy in part by addressing an issue with ocean temperature data during the second world war, when measurements were more often made from warmer engine room intakes than from buckets lowered over the side of ships. This has resulted in a bias, inflating estimated surface temperatures in the early-to-mid 1940s. The new study removed this bias by focusing on temperatures along continental and island coastlines.[…]
They found that the 0.4C warming from 1910 to 1945 could be accounted for by 0.2C warming from human greenhouse gases offset by 0.08C cooling from human aerosol pollution, 0.2C warming from natural factors (mostly a quiet period for volcanic activity plus a small contribution from increased solar activity), and a bit of natural variability plus some remaining uncertainty in the data.
Since 1950, the authors found that the 0.8C temperature rise is due to 1.2C warming from greenhouse gases offset by 0.3C cooling from human aerosol pollution and 0.1C cooling from volcanoes and the sun.
These findings are important because they improve global surface temperature estimates, explain the causes of the early-20th century warming, and reaffirm that as the IPCC concluded in 2013, humans are responsible for all of the rapid global heating since 1950.”

























tirsdag 11. juni 2019

Al Gore "failed" predictions debunked

While there are minor errors in An Inconvenient Truth, the main truths presented - evidence to show mankind is causing global warming and its various impacts is consistent with peer reviewed science.


http://www.realclimate.org/index...

http://ninepoints.pbworks.com/w/...

https://www.skepticalscience.com...

And, do you think they’d give him a Nobel Prize if the science was that bad?


The Nobel Peace Prize 2007

The Nobel Peace Prize 2007 was awarded jointly to Intergovernmental Panel on Climate Change (IPCC) and Albert Arnold (Al) Gore Jr. "for their efforts to build up and disseminate greater knowledge about man-made climate change, and to lay the foundations for the measures that are needed to counteract such change."
THE AL GORE POLAR ICE PREDICTION SMEAR CAMPAIGN DEBUNKED:
WHY DO WE NEVER SEE AMATEUR DENIERS LINKING TO GORES "QUOTE" ABOUT THE POLAR ICE?
HINT;
HE NEVER SAID IT.
Gores predictions about artic ice was about
SUMMER ice.
In the artic.
The word SUMMER is always left out when denier bloggs recycle this lie story. And it was only about
"some of the summer months".
The NASA report was about Antartica ice. (Misrepresented by deniers). Thus the meme in question is also comparing a quote on north pole ice to Antartica. Another lie.
The Navy researcher that leads this "new study" team that the former vice president alludes to is Wieslaw Maslowski at the Naval Post Graduate School in Monterey, California. The team's research was funded by the Department of Energy (DOE), the Office of Naval Research (ONR), the National Science Foundation (NSF), the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA).
Maslowski also
did not say "by 2013"
in his original research in 2007 or when it was republished in 2009. This grandstanding about sea ice and Gore, for whatever reason, is a huge and egregious deception. The actual prediction from Maslowski's 2009 publication is, "Autumn could become near ice free between 2011 and 2016."
One study estimated that it could be completely gone during summer in less than 22 years."
So in reality, Gore tried to echo one of Maslowski's prediction predictions. Maslowski's prediction, originally made in 2006, was that Arctic sea ice would decline to <1,000,000 square kilometers extent (with no ice at the North Pole) by the end of the September melt by 2016, +/- 3 years. So 2013-2019...and still valid today.
Gore picked the worst scenario and didnt even refer to it accurate.
THE SMEAR CAMPAIGNS:
As an online climate change debate grows longer, the probability that denier arguments will descend into attacks on Al Gore approaches 1."
“The problem with attacking Al Gore is that he has absolutely xxxx all to do with the science of climate change, no matter his carbon footprint, PMRC involvement, Manbearpig, etc. You really can't find a better instance of poisoning the well. He could live in a mud hut and walk everywhere and they'd call him a hypocrite because the aglets on his shoelaces were made of plastic, a petroleum product. ”
The claim that Gore and his ilk are hypocrites is a classic conservative attack strategy of redirection (because it ignores the core issue of climate change) and of poisoning the well (because it attempts to discredit the message by discrediting the messenger).This is much easier, and perhaps more rhetorically effective, than debunking climate science itself. That’s why you only see groups like the National Center for Public Policy Research releasing “studies” on Gore’s energy use. NCPPR, which has been funded by oil interests, advocates against policies to fight global warming because it denies that global warming exists.
“The world isn’t warming,” the group falsely claimed in a 2014 paper arguing against climate regulations. Thus, it’s in their interest to try to undermine one of the most effective advocates of aggressive climate action.
And isnt it convenient?
If Gore doesn’t invest in green energy companies, you call him a hypocrite who isn’t willing to put his money were his mouth is. If he does, you accuse him of having a conflict of interest. Either way, you get to avoid actually considering what he’s saying.
I don’t give a crap what politicians and the media think or say. Both of them are repeatedly wrong about the science (on both “sides” of the topic). So I don’t care what Al Gore said or thinks, I don’t care what erroneous claims CNN or Fox News has made, etc. I care about the science, and the scientific evidence overwhelmingly shows that climate change is happening and it is our fault. Can people spin that for personal gain? Sure, but that doesn’t make the science any less true.
Using politicians and the media to attack science is a guilt by association fallacy, because what they think, say, and do is completely, 100% irrelevant to whether or not the science is correct. I care about what peer-reviewed studies have found, not what politicians and news anchors say.
And behold:
The Michael Jordan Fallacy
This one can be used to impugn the motives of anyone in the world, in an effort to prove they are driven by greed and don't care about anyone else's problems:
"Just think if Michael Jordan had used all his talents and wealth to feed third world children, rather than to play a sport."
Of course, you can say this about anyone, famous or not:
"If your doctor really cared about people's health, he'd sell everything he owned and become a charitable frontier doctor in Africa."
Climate science was a bipartisan issue until fossil fuels money flooded the republican party some 20 years ago.
GORE IS NOT A SCIENTIST.
When scientists do make their predictions, its based upon reports from many researchers all around the world. Not one group of researchers or individuals.
Go directly to the scientists and to the peer reviewed science.
Using Gores "failed" predictions about polar ice is a major red herring used by deniers to look away from the fact that artic ice is at a record low:
From NOAA's December 12, 2017 Arctic Report Card:
Sea ice loss "is beyond the range of natural variability, implying a human component to the drastic decrease observed in the records."
"This time series shows the Arctic sea ice extent in millions of square kilometers over the past roughly 1,500 years. Scientists use climate proxies like sediment/ice cores, tree rings, and fossilized shells of ocean creatures to extend the sea ice extent records back in time. These records show that while there have been several periods over the past 1,450 years when sea ice extents expanded and contracted, the decrease during the modern era is unrivaled. And just as importantly, it is beyond the range of natural variability, implying a human component to the drastic decrease observed in the records."The minimum sea ice extent, which occurs each summer, is influenced by the atmospheric circulation, air temperature, and variations in the amount of warm water that flows into the Arctic. Since 1900, waters that enter the Arctic Ocean through the Fram Strait have increased by 2 degrees Celsius (4 degrees Fahrenheit). Meanwhile, proxy records show that the current warming trend in surface air temperatures has not been observed in the Arctic over at least the last 2,000 years."



Sea ice extent in the Bering Sea was the 2nd lowest on record in February 2019 (after last year). This isn't some obscure statistic. This has significant impacts to Alaskan communities and ecosystems.

"The annual mean Arctic sea-ice extent decreased over the period 1979 to 2012, with a rate that was very likely in the range 3.5 to 4.1% per decade. Arctic sea-iceextent has decreased in every season and in every successive decade since 1979, with the most rapid decrease in decadal mean extent in summer (high confidence). It is very likely that the annual mean Antarctic sea-ice extent increased in the range of 1.2 to 1.8% per decade between 1979 and 2012.
"Arctic temperatures are rising faster than the global average. The Arctic was warmer from 2011 to 2015 than at any time since instrumental records began in around 1900, and has been warming more than twice as rapidly as the world as a whole for the past 50 years. January 2016 in the Arctic was 5°C warmer than the 1981–2010 average for the region, a full 2°C higher than the previous record set in 2008, and monthly mean temperatures in October through December 2016 were 6°C higher than average for these months. Sea temperatures are also increasing, both near the surface and in deeper water"
BONUS :
DEBUNKING "THE MOVIE WAS BANNED IN ENGLAND AND HAD 9 ERRORS MYTH":
UK High Court judge rejected a call to restrict the showing of Al Gore’s An Inconvenient Truth (AIT) in British schools.
The judge, Justice Burton found that “Al Gore’s presentation of the causes and likely effects of climate change in the film was broadly accurate”(which accords with our original assessment). There has been a lot of comment and controversy over this decision because of the judges commentary on 9 alleged “errors” (note the quotation marks!) in the movie’s description of the science. The judge referred to these as ‘errors’ in quotations precisely to emphasize that, while these were points that could be contested, it was not clear that they were actually errors.
There are a number of points to be brought out here. First of all, “An Inconvenient Truth” was a movie and people expecting the same depth from a movie as from a scientific paper are setting an impossible standard. Secondly, the judge’s characterisation of the 9 points is substantially flawed. He appears to have put words in Gore’s mouth that would indeed have been wrong had they been said (but they weren’t). Finally, the judge was really ruling on how “Guidance Notes” for teachers should be provided to allow for more in depth discussion of these points in the classroom.
  • Ice-sheet driven sea level rise Gore correctly asserted that melting of Greenland or the West Antarctic ice sheet would raise sea levels 20ft (6 meters). In the movie, no timescale for that was specified, but lest you think that the 20 ft number is simply plucked out of thin air, you should note that this is about how much higher sea level was around 125,000 years ago during the last inter-glacial period. Then, global temperatures were only a degree or two warmer than today – and given that this is close to the minimum temperature rise we can expect in the future, that 20 ft is particularly relevant. The rate at which this is likely to happen is however highly uncertain as we have discussed previously.
  • Pacific island nations needing to evacuate Much of Tuvalu is only a few feet above sea level, and any sea level rise is going to impact them strongly. The impacts are felt in seemingly disconnected ways – increasing brine in groundwater, increasing damage and coastal erosion from tides and storm surges, but they are no less real for that. The government of Tuvalu has asked New Zealand to be ready to evacuate islanders if needed, and while currently only 75 people per year can potentially be resettled, this could change if the situation worsened.
    In the movie there is only one line that referred to this: “That’s why the citizens of these pacific nations have all had to evacuate to New Zealand”, which is out of context in the passage it’s in, but could be said to only be a little ahead of it’s time.
  • Climate impacts on the ocean conveyor The movie references the Younger Dryas event that occurred 11,000 years ago when, it is thought, a large discharge of fresh water into the North Atlantic disrupted the currents, causing significant regional cooling. That exact scenario can’t happen again, but similar processes are likely to occur. The primary unresolved scientific issue regards how quickly the circulation is likely to change as we move forward. The model simulations in the latest IPCC report show a slowdown in the circulation – by about 30% by 2100 – but there is much we don’t understand about modeling that circulation and future inputs of freshwater from the ice sheets, so few are willing to completely rule out the possibility of a more substantial change in the future. Further discussion on what this really means and doesn’t mean is available here and here.
  • CO2 and Temperature connections in the ice core record Gore stated that the greenhouse gas levels and temperature changes over ice age signals had a complex relationship but that they ‘fit’. Again, both of these statements are true. The complexity though is actually quite fascinating and warrants being further discussed by those interested in how the carbon cycle will react in the future. We’ve discussed the lead/lag issue previously. A full understanding of why CO2 changes in precisely the pattern that it does during ice ages is elusive, but among the most plausible explanations is that increased received solar radiation in the southern hemisphere due to changes in Earth’s orbital geometry warms the southern ocean, releasing CO2 into the atmosphere, which then leads to further warming through an enhanced greenhouse effect. Gore’s terse explanation of course does not mention such complexities, but the crux of his point–that the observed long-term relationship between CO2 and temperature in Antarctica supports our understanding of the warming impact of increased CO2 concentrations–is correct. Moreover, our knowledge of why CO2 is changing now (fossil fuel burning) is solid. We also know that CO2 is a greenhouse gas, and that the carbon cycle feedback is positive (increasing temperatures lead to increasing CO2 and CH4), implying that future changes in CO2 will be larger than we might anticipate.
  • Kilimanjaro Gore is on even more solid ground with Kilimanjaro. In the movie, the retreat of Kilimanjaro is not claimed to be purely due to global warming , but it is a legitimate example of the sort of thing one expects in a warmer world, and is consistent with what almost all other tropical mountain glaciers are doing. There is indeed some ongoing discussion in the literature as to whether or not the retreat of ice on Kilimanjaro is related to the direct effects (warming atmospheric temperatures) or indirect effects (altered patterns of humidity, cloud cover, and precipitation influencing Kilimanjaro’s ice mass) of climate change, and that argument isn’t yet over. But these arguments would be of more relevance if (a) we were not witnessing the imminent demise of an ice field that we know has existed for at least the past 12,000 years and (b) most of the other glaciers weren’t disappearing as well.
  • Drying up of Lake Chad It is undisputed that Lake Chad has indeed shrunk rapidly in recent decades. While irrigation and upstream water use are probably contributing factors, the dominant cause is the reduction of rainfall across the entire Sahel from the 1950s to the 1980s and with rainfall today still substantially below the high point 50 years ago. There is substantial evidence that at least a portion of this drying out is human-caused. A few recent papers (Held et al, PNASChung and Ramanathan and Biasutti and Giannini) have addressed causes ranging from Indian Ocean changes in sea surface temperature to the increase in atmospheric aerosols in the Northern hemisphere. Gore uses this example to illustrate that there are droughts in some regions even while other areas are flooding. Unfortunately this is exactly what the models suggest will happen.
  • Hurricane Katrina and global warming Katrina is used in the film as a legitimate illustration of the destructive power of hurricanes, our inability to cope with natural disaster, and the kind of thing that could well get worse in a warmer world. Nowhere does Gore state that Katrina was caused by global warming. We discussed this attribution issue back in 2005, and what we said then still holds. Individual hurricanes cannot be attributed to global warming, but the statistics of hurricanes, in particular the maximum intensities attained by storms, may indeed be.
  • Impact of sea ice retreat on Polar bears As we presaged in August, summer Arctic sea ice shattered all records this year for the minimum extent. This was partially related to wind patterns favorable to ice export in the spring, but the long term trends are almost certainly related to the ongoing and dramatic warming in the Arctic. Polar bears do indeed depend on the sea ice to hunt for seals in the spring and summer, and so a disappearance of this ice is likely to impact them severely. The specific anecdote referred to in the movie came from observations of anomalous drownings of bears in 2004 and so was accurate. However, studying the regional populations of polar bears is not easy and assessing their prospects is tough. In the best observed populations such as in western Hudson Bay (Stirling and Parkinson, 2006), female polar bear weight is going down as the sea ice retreats over the last 25 years, and the FWS is considering an endangered species listing. However, it should be stated that in most of the discussions about polar bears, they are used as a representative species. Arctic ecosystems are changing on many different levels, but it is unsurprising that charismatic mega-fauna get more press than bivalves. In the end, it may be the smaller and less photogenic elements that have the biggest impact.
  • Impact of ocean warming on coral reefs Corals are under stress from a multitude of factors; overfishing, deliberate destruction, water pollution, sea level rise, ocean acidification and, finally, warming oceans. The comment in the movie that rising temperatures and other factors cause coral bleaching is undoubtedly true. Bleaching episodes happen when the coral is under stress, and many examples have been linked to anomalously warm ocean temperatures (Australia in 1998 and 2002, all over the Indian Ocean in recent years). Corals are a sobering example of how climate change exacerbates existing vulnerabilities in eco-systems, potentially playing the role of the straw that breaks the camel’s back in many instances.
Overall, our verdict is that the 9 points are not “errors” at all (with possibly one unwise choice of tense on the island evacuation point). But behind each of these issues lies some fascinating, and in some cases worrying, scientific findings and we can only applaud the prospect that more classroom discussions of these subjects may occur because of this court case.
ANd:
Lambert goes on to look closely at the nine contended points. His conclusion:
Overall, there are a couple of points where I wish Gore would have talked about timescales and probabilities (sea level rise and thermohaline circulation), and a couple of examples that could have been better chosen (Kilimanjaro and Lake Chad). Burton was mistaken on the other points where he felt that Gore went past the consensus. I don’t think that there is any harm in the Guidance Notes on Burton’s nine points, but the usual suspects will, of course, ignore the fact that the judge found that Gore was “broadly accurate” and try to make it look as if there are serious problems with AIT and climate science.

Out of this — a judge rejects the suit, but finds nine points in the film he thinks differ slightly from the consensus, and it turns out he’s wrong about several and the others were at best matters of interpretation, omission, or insufficient context — the mainstream media pulled, in the words of an AP headline I saw earlier this evening, “Judge Says Gore Movie Not Scientific” (it has since been changed).

Magnetic poles / Earth's magnetic field

While the Earth's magnetic axis is shifting somewhat, Earth's rotational axis shifts only a little bit, mostly in response to th...