From the UNIVERSITY OF ROCHESTER In February NASA astronomers discovered seven Earth-like planets, potentially harboring life, orbiting the star TRAPPIST-1, not too far from Earth. Scientists have yet to discover life, or evidence of civilizations, on these or other planets. But in the search for extra-terrestrial intelligence, they often categorize hypothetical worlds according to the amount…
via Watts Up With That?
September 8, 2017 at 10:54AM
Regarding hurricanes NOAA has issued a statement; “It is premature to conclude that human activities – and particularly greenhouse gas emissions that cause global warming – have already had a detectable impact on Atlantic hurricane or global tropical cyclone activity.”
Hurricanes aside, the evidence for increased extreme events occurring at the moment is not very impressive.
The IPCC’s SREX report of 2012 said there is some evidence of change in some extremes going back to the 1950s. It is very likely that there has been an overall decrease in the number of cold days and nights for North America, Europe and Australasia, and with medium confidence Asia. There is also medium confidence for a change in the length and number of warm spells and heat waves. It is likely that more regions have experienced increases than decreases in heavy precipitation events, though there are large regional uncertainties. It is likely that there has been a poleward shift in northern and southern hemisphere extra tropical storm tracks.
There is medium confidence that some regions have experienced more intense and longer droughts in Southern Europe and Western Australia, but not in Central North America and North West Australia where droughts are less frequent and less intense. There is limited to medium confidence in changes in the magnitude and frequency of floods. SREX goes on to add that there is low confidence of any changes on a global scale with uncertainty as to even the sign of the changes. It is also likely that there might have been changes in coastal high water events.
Descriptions such as “likely” and “medium confidence” are not very firm scientific statements. They do not provide a reliable scientific base from which to discuss the possible effects of man-made climate change. The public, and many advocates, do not realise this weakness, but that doesn’t matter because the subtleties are usually ignored anyway.
An abstract from a paper by Sarojini, Stott and Black, published four years later in Nature Climate Change is no more impressive in the face of a growing realisation of the scale of uncertainties involved in identifying changes.
“Understanding how human influence on the climate is affecting precipitation around the world is immensely important for defining mitigation policies, and for adaptation planning. Yet despite increasing evidence for the influence of climate change on global patterns of precipitation, and expectations that significant changes in regional precipitation should have already occurred as a result of human influence on climate, compelling evidence of anthropogenic fingerprints on regional precipitation is obscured by observational and modeling uncertainties and is likely to remain so using current methods for years to come.”
It’s clear that looking at changes in occurrence rates and other changing parameters is going to take a long time. So some scientists have used a different technique. They compare observations to a virtual Earth on which there has been no man-made climate change. The justification is that there has been improvements in models, and besides they know what should be happening and that makes detecting it easier. The Nature Climate Changes paper adds, “Historical records are not conclusive, large uncertainties, have to wait a long time for the effect to show up. However expected changes may render risks based on historical data inaccurate.” In summary, you don’t get your data through nature, you get it through models.
The idea is to look at a particular heat wave and rerun it on an Earth where man-made climatic effects have been removed. If it’s stronger or longer in the real world than the virtual one the man-made climatic changes have increased its severity or frequency. If you wish you can add some numbers saying the event was made 50% or perhaps ten times more likely because of man-made climate change.
Of course it all depends upon the models and our ability to remove man-made changes from the observations. What’s worrying is that the climate models are very poor at projections and fail to adequately capture the real world. That’s something that has been admitted many times when discussing the so-called hiatus period in global surface temperatures. The hiatus lesson is that decadal natural variability is not understood. The result is, as the Nature Climate Change paper said, large uncertainties.
The process of the detection and attribution of extreme events to man-made climate change is a young one and despite papers published in peer-reviewed journals, which many mistake for statements of certainty, it is tentative. For the public however its power, skill and uncertainties are being misrepresented.
How many hurricanes feature in Al Gore’s Inconvenient Sequel movie I wonder?
Feedback: david.whitehouse@thegwpf.com
via The Global Warming Policy Forum (GWPF)
September 8, 2017 at 10:05AM
by Judith Curry
Cat 5 Hurricane Irma is one for the record books; it’s eye is on Florida.
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Summary
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Well, the 12 year drought of major hurricane landfalls in the U.S. is ending with a vengeance in 2017. Following the devastation in Texas by Hurricane Harvey, Hurricane Irma is bearing down on Florida. Landfall is expected this weekend. This blog post provides forecast history for Irma, and the latest predictions from my company, Climate Forecast Application Network (CFAN). And finally, I address the debate on the link between hurricanes and global warming.
Genesis of Irma
On 8/25, we began monitoring an African Easterly wave that was expected to form and was showing some early signs of developing into a tropical cyclone.
The National Hurricane Center (NHC) issued an invest on 8/28. The plot below shows an early forecast from CFAN, showing CFAN’s calibrated tracks and intensities for the ECWMF deterministic (red) and the ensemble mean (black). The NOAA GFS ensemble forecast was similar.
Irma became a named storm on 8/30. By 8/30, the tracks for the ECMWF model were shifting closer to Florida
CFAN’s calibrated probability distribution of tracks on 8/30 showed: 38% of the tracks in the Gulf of Mexico for ECMWF, and 23% of the tracks from NOAA GEFS in the Gulf of Mexico.
Intensification
Irma became a hurricane on 8/31. CFAN’s calibrated track probabilities are shown below for ECMWF (top) and NOAA GEFS (bottom).
For reference, the sea surface temperatures (ECMWF operational analysis) is shown below. Irma formed where SST was about 80F (26.5C).
In a matter of a few hours, Irma became a major hurricane. The surprising thing about this development into a major hurricane was that it developed over relatively cool waters in the Atlantic – 26.5C — the rule of thumb is 28.5C for a major hurricane (and that threshold has been inching higher in recent years). On 8/31, all the models were predicting a major hurricane to develop, with some hints of a Cat 5.
So why did Irma develop into a major hurricane? We can’t blame 26.5 C temperatures in the mid Atlantic on global warming.
The dynamical situation for Irma was unusually favorable. In particular, the wind shear was very weak.
Further, the circulation field (e.g. stretching deformation) was very favorable for spinning up this hurricane.
Irma intensified to Cat 5 on 9/5. This intensification was picked up by the models on 8/31, but at this point it was mostly a case of ‘right answer for the wrong reason’, since the models hadn’t yet settled down regarding track.
Astonishingly, Irma has hung on to its Cat 5 status through the time of this writing.
Zeroing in on the track
The track forecast for Irma has been challenging because of:
A Florida landfall has been the favored prediction from CFAN’s calibrated ECMWF tracks since 9/03:
The NHC models have vacillated a bit more – in the diagram below, focus on the GFS (blue), HWRF (orange), HMON (green).
The value add of CFAN’s track calibration and Monte Carlo resampling technique is particularly evident in the earlier ECMWF track forecasts:
CFAN’s calibrated ECMWF tracks with Monte-Carlo resampling
Raw ECMWF
Several interesting analyses re Irma’s track forecast biases:
Landfall impacts
At the time of this post, Irma’s intensity has dropped to Cat 4 after an eyewall replacement cycle.
Here is CFAN’s latest cone of uncertainty for ECMWF (top) and NOAA GEFS (bottom):
Here is CFAN’s high predictability cluster from ECMWF (red is deterministic, bold black is ensemble mean):
Here are the latest tracks from NHC (blue is GFS, green is HMON, orange is HWRF)
Here is max wind speed plot for Florida, based on CFAN’s calibrated winds from ECMWF DET:
Here is an estimate of the storm surge from Irma (fortunately landfall on Sunday around 2 am will be low tide):
Global warming
Ever since Hurricane Harvey, the global warming – hurricane hysteria has ratcheted up to levels I haven’t seen since 2006.
NOAA GFDL has written a good article on Global Warming and Hurricanes. Their main conclusions:
I agree wholeheartedly with #1. I agree qualitatively with 2-4, but GFDL has much greater faith in the models than I do (and of course the 21st century projections assume substantial warming, which I don’t necessarily agree with). However, I much prefer their model-based quantitative estimates (but they need some serious uncertainty estimates, including structural uncertainty), relative to hysterical arm waving by Mann and Trenberth using undergraduate basic thermodynamics reasoning. There is nothing basic or simple about hurricanes.
I include this text from my 2010 post Hurricane Katrina – 5 years later, particularly relevant given the cool SST values that Irma formed and intensified.
The relationship between sea surface temperature and hurricane intensity. The causal chain for global warming to increase hurricane intensity has been argued to occur via the increase in sea surface temperature (SST) (e.g. Curry et al. 2006 ). A nominal SST threshold of 26.5-27oC is used as a criterion for tropical cyclogenesis, and a nominal threshold of 28.5oC for intensification to a major hurricane. Some new insights into the relationship between a warming climate and hurricane intensity is suggested by Hoyos and Webster (2010, forthcoming). During the latter half of the 20th century, the tropical warm pool defined by the isotherm of 28oC has expanded in area. However, the region of tropical cyclogenesis has not expanded, owing to the area of convective activity remaining nearly constant. Hoyos and Webster argue that the temperature threshold for tropical cyclogenesis increases as the average tropical ocean temperature increases. It is the increasing intensity of the convection with warmer temperatures that seems to be the link between SST increase and hurricane intensity, rather than the absolute value of the SST itself. Further, the location of the intense convection is related to the difference between the local SST and global tropical average SST, rather than to the absolute value of the SST itself (Vecchi et al. 2008)
This is particularly relevant for interpretating the formation of extremely strong hurricanes in the early half of the 20th century, when SSTs were significantly cooler.
At some point, probably in the 2020’s, the Atlantic Multidecadal Oscillation (AMO) will flip to the cool phase (which typically lasts several decades), which is associated with low Atlantic hurricane activity. At this point, natural variability (interannual, decadal, multi-decadal) is swamping any potential signal of global warming on hurricanes.
After I wrote the above article, I spotted this article by Chris Mooney: The science behind the strange hurricane ‘drought’ — and its sudden end. This para illustrates the level of disagreement and faulty reasoning on this whole topic:
“A debate continues about why the 1970s and 80s were relatively quiet in the Atlantic,” said MIT hurricane researcher Kerry Emanuel. “Some believe that it was the consequence of a natural climate oscillation called the Atlantic Multi-decadal Oscillation (AMO), while others, including me, think is was mostly a consequence of sulfate aerosol pollution.”
I guess Kerry Emanuel didn’t read the IPCC AR5 or any of the more recent research, showing that sulfate aerosol forcing of climate (generally, and also mid 20th century) is much smaller than thought circa the AR4. Not to mention the massive amounts of sulfate being emitted by Asia in recent decades.
Florida preparedness
In contrast with Texas, Florida is massively prepared for hurricanes, with strict building codes, emergency management procedures, and comprehensive procedures to rapidly restore electric power.
That said, this is the biggest and baddest landfall strike in the U.S. in a long time. Irma is worse than Andrew (1992) and Wilma (2005), which were also Cat 5; Irma has a large horizontal extent, which means larger swath of hurricane force winds, bigger storm surge, more rainfall and tornadoes.
Lets see how it plays out, but I anticipate that this will go much better than Hurricane Harvey and Houston.
I’ve been talking with Floridians that remember Andrew (1992). I reminded them how MUCH better the forecast information is now, relative to 1992.
Apart from Florida, Georgia and the Carolinas are also facing impacts from Irma. Atlanta could see hurricane force winds! From a massive storm like this, there will be perhaps a hundred tornadoes generated inland, mostly in the right forward quadrant of the storm.
Operational notes
Huge thanks and acknowledgements to CFAN’s Jesse Marks, Violeta Toma and our software engineers for sleepless nights and doing a tremendous job in ensuring the timely delivery of our forecast products in this very challenging operational environment. I will need to dish out some good bonuses in their September pay checks.
Stay safe everyone!
via Climate Etc.
September 8, 2017 at 09:43AM
But while the U.S. may be the only country producing commercially significant volumes of shale today, it’s not the only one with sizable shale reserves—according to the U.S. Energy Information Administration, Argentina, Algeria, and China all have more shale gas than the United States, and Russia has nearly as much tight oil. Given the American example of the transformative power of this recently “unlocked” resource, there’s plenty of motivation for these countries to get the hydrocarbons flowing, and there has been for many years. So where are they now?
Let’s start in Argentina, which contains the Vaca Muerta shale formation, one of the world’s largest. Argentina has more shale gas than the United States, and is second only to China, but thus far has yet to ramp up commercial production. But companies are spending more money on exploratory drilling in the region (to the tune of $1 billion per year), and according to Argentinian Energy Minister Juan José Aranguren, the Vaca Muerta will attract $15 billion annually in investment by 2020. That influx of foreign capital will be in many ways dependent on further market reforms—price controls, labor unions, and extensive subsidies have all been barriers to entry into Argentina’s fledgling shale industry. Meanwhile, production costs are, according to the country’s state-owned oil and gas company YPF, falling far enough to allow certain shale plays to turn a profit in today’s bargain crude market. Still, YPF’s shale chief admitted that the Vaca Muerta formation requires a lot more infrastructure to become competitive. With more strident market reforms, more foreign investment, and more developed oil and gas field infrastructure, Argentina can kick off its own shale success story.
Those same problems crop up elsewhere in the world, though other countries have their own unique challenges. In Algeria, there’s not yet enough demand for shale gas to kickstart the industry there. Algeria’s Energy Minister Noureddine Boutarfa said earlier this year that the country “doesn’t need, in the short term, to use its shale gas, because it has other natural resources, including [conventional] gas.” Algeria also has a state-owned oil company that controls the country’s hydrocarbon reserves, which makes it difficult to secure the foreign involvement so necessary to succeed in the technologically difficult shale space.
Russia has a similar demand problem, as the country already produces huge quantities of oil and gas in its conventional fields. But as these fields mature, production is slowing, and eyes are turning toward unconventional (read: shale) reserves for the future. No Russian shale formation is more promising than the Bazhenov, which the EIA estimates contains 74.6 billion barrels of tight oil, just shy of America’s estimated reserves. Moscow was slow to embrace the shale boom, initially dismissing it as a fringe phenomenon, but thanks to the current price of oil (in large part a result of surging American output from fracking), it now recognizes the importance of these unconventional reserves. But U.S. sanctions have prevented Western companies from plumbing the Bazhenov shale, and without the expertise, equipment, and technology that those firms have developed in America’s various shale formations, Russia has been unable to unlock its own. That may be changing, though, as Gazprom Neft—the oil division of the state-owned gas company Gazprom—has begun trying to frack without American assistance. As Gazprom Neft’s director of exploration Alexei Vashkevich put it, “it’s not a question of will we do it or not: it’s a question of time. It might take a little bit longer but we will get there.” That seems to be something of a theme for shale development outside of the United States—it’s a question of when, not if.
In the UK, shale progress has been stymied more by public opposition than by a lack of private investment, but there are green shoots in the country that contains some 1.3 quadrillion cubic feet of shale gas. Just this past month, the British company Cuadrilla began drilling the first shale well in the country since 2011, after the industry was shut down following a series of small earthquakes near exploratory shale operations. The British public is still deeply skeptical of fracking, though, and lacking any mineral rights, landowners have little reason to go along with the extraordinary disruptions that accompany major oil and gas projects. Theresa May’s government is setting up a Shale Wealth Fund, supported by taxes levied on shale firms, that will compensate affected communities, but it will still be an uphill battle to bring people around in a country with a higher average population density than those regions of the United States where shale is being drilled most vigorously.
Australia has seen political support wane for fracking, and just this week the state of Western Australia, led by the recently elected Left-leaning Labor Party, moved to ban the drilling process. It’s the fifth Australian state to place limits on hydraulic fracturing, leaving only two states—South Australia and Queensland—where the practice is permitted. That’s a big blow for a country which is estimated to contain 429 trillion cubic feet of shale gas, roughly two-thirds of America’s shale gas resource base.
But we’ve saved the best for last, and China may be the closest to replicating the American shale experience.
via The Global Warming Policy Forum (GWPF)
September 8, 2017 at 09:07AM
Iowa Climate Science Education 