Tropical cyclones in the Australian region are influenced by a number of factors, and in particular variations in the El Niño – Southern Oscillation. In general, more tropical cyclones cross the coast during La Niña years, and fewer during El Niño years.
Analysis of historical tropical cyclone data has limitations due to a number of changes in observing practices and technology that have occurred over time. With new and improved meteorological satellites our ability to detect tropical cyclones has improved, as has our ability to differentiate tropical cyclones from other tropical weather systems such as monsoon depressions, which in the past may have been incorrectly named as tropical cyclones. A particularly important change occurred in the late 1970s when regular satellite images became first available from geostationary satellites above the Earth’s equator.
(…) We are left with conjectures and other speculation, both in the recent past and for the future. For this, climatologists develop models with which they can test their hypotheses. But these models are obviously overheating. (…)
Global methane emissions from agriculture are larger than estimated due to the previous use of out-of-date data on carbon emissions generated by livestock, according to a study published in the open access journal Carbon Balance and Management.
In the last 4 months, 40 more graphs taken from 30 more new peer-reviewed scientific papers have made their way into the ever-growing volume of evidence that today’s climate is not only not unprecedented or unusual in the context of the last millennium, but modern temperature values are still among the coldest of the last 10,000 years.
Overall, initial figures suggest that Greenland may have gained a small amount of ice over the 2016-17 year. If confirmed, this would mark a one-year blip in the long-term trend of year-on-year declines over recent decades.
by Tony Heller, September 29, 2017 in DeplorableClimSciBlog
Ninety years ago brought the worst floods in US history. The Mississippi River was flooded for more than six months, forcing hundreds of thousands of people to abandon their homes permanently. Vermont’s worst flood on record occurred in November, 1927. The Red Cross described 1927 as the worst year in history.
A number of authors, including the IPCC, have argued that climate models have systematically overstated the rate of global warming in recent decades. A recent paper by Millar et al. (2017) presented the same finding in a diagram of temperature change versus cumulative carbon emissions since 1870.
In the climate debate, though, it pays to read the small print. Official climatology does not usually admit its many errors: instead, we are ordered to obey the “consensus”, as the Party Line is these days rebranded. On reading the headlines, I suspected at once that the true purpose of the latest admission, by Millar et al. in the current issue of Nature Geo“science”, is to minimize and thus to conceal the true magnitude of past over-predictions.
Solar activity during the current sunspot minimum has fallen to levels unknown since the start of the 20th century. The Maunder minimum (about 1650–1700) was a prolonged episode of low solar activity which coincided with more severe winters in the United Kingdom and continental Europe. Motivated by recent relatively cold winters in the UK, we investigate the possible connection with solar activity. We identify regionally anomalous cold winters by detrending the Central England temperature (CET) record using reconstructions of the northern hemisphere mean temperature.
L’incroyable nouvelle a été annoncée par Mathieu Vidard dans l’émission La Tête au carrésur France Inter, le 20 septembre 2017 (ici, très brièvement, à partir de 10’, il faut bien viser) :
Maintenir le réchauffement climatique en dessous de 1,5°C, c’est encore possible, c’est l’objectif qui avait été fixé par les Accords de Paris à l’issue de la COP 21. La bonne nouvelle vient d’une équipe de recherche internationale. D’après leurs analyses, l’ampleur du réchauffement climatique qui a déjà eu lieu a été surestimée et la quantité de carbone que l’humanité peut émettre à partir de 2015 en restant en-dessous de ce seuil de 1,5°C serait trois fois supérieure à ce qui avait été annoncé.
“Les faits, et seulement les faits” doivent nous éclairer et nous préserver de malentendus entourant toute discussion, alors que l’administration Trump a pris la décision de se retirer de l’Accord de Paris COP21 (2015) qui traite du changement climatique.
Si vous pensez que la conférence sur le climat qui se tiendra à Paris en décembre 2015 (COP21) a quelque chose à voir avec le climat ou la protection de la nature, révisez votre copie. Vous avez tout faux. Les premiers qui s’en rendront compte, après avoir vainement fouillé dans les derniers recoins de ces futurs accords, minimalistes et non-contraignants mais présentés par les politiques comme une grandiose réussite pour l’environnement et le climat, seront les écolos et certaines ONG environnementales.
“It is tempting to say that the record low we are seeing this year is global warming finally catching up with Antarctica,” Meier said. “However, this might just be an extreme case of pushing the envelope of year-to-year variability. We’ll need to have several more years of data to be able to say there has been a significant change in the trend.”
Partly in response to the crazy claims of the usual global warming experts (Stevie Wonder, Beyoncé, Jennifer Lawrence, Mark Ruffalo, Bill Nye the Science Guy, Neil deGrasse Tyson, Pope Francis), I decided to write another Kindle e-book. This one is entitled, Inevitable Disaster: Why Hurricanes Can’t Be Blamed On Global Warming.
by P. Homewood, September 22, 2017 in NotaLotofPeopleKnowThat
As Hurricane Maria heads north as a Cat 3 storm, much is being made of the fact that it is the strongest hurricane to hit Puerto Rico since 1928. The implication is that Maria must have been exceptionally strong.
But the reality is that Puerto Rico is little more than a speck in the vastness of the Atlantic Ocean. The odds of the eye of a major hurricane, often just 10 or 20 miles wide, making a direct hit on Puerto Rico are probably hundreds to one, given that there are thousands of miles of ocean through which hurricanes can commonly travel.
With the help of satellite observations from 188 lakes worldwide, scientists have shown that the warming of large lakes amplifies their color. Lakes which are green due to their high phytoplankton content tend to become greener in warm years as phytoplankton content increases. Clear, blue lakes with little phytoplankton, on the other hand, tend to become even bluer in warm years caused by declines in phytoplankton. Thus, contrary to previous assumptions, the warming of lakes tends to amplify their richness or poverty of phytoplankton.
Results indicate climate models where the initiation of glaciation depends strongly on CO2concentrations over astronomical controls significantly overpredict the duration of the present-day warm period compared to past interglacial analogs.
(…) Upon our return to the Hotel after visiting the Glacier, we noticed that our brand-new photos appear to show that the Grinnell Glacier has grown slightly from the 2008 images that are displayed on the Hotel walls. There has been no reporting of this in any newspaper or broadcast that we know of. (In fact, all news coverage reports the precise opposite.) The smaller Gem Glacier—which is visible from the valley miles below—also appears to be slightly larger than it is shown in 2008 pictures on display.
by Sebastien Laye, September 18, 2017 in NotaLotofPeopleKnowThat
Those voices are the impetus behind what Subramanian calls a “green and clean coal coalition” spanning both the developed and developing worlds. Emerging markets in Asia and Africa will continue to build new coal-fired power stations for at least the next two decades. In that timeframe, coal-fired solutions are indispensable to meeting their demands for electrification and growth. As clean coal solutions emerge, new plants in the developing world can and should be far cleaner than previous generations of coal-fired plants in Europe and America.
The study is published in the journal Nature Geoscience by a team of scientists led by Richard Millar of the University of Oxford. It has recalculated the carbon budget for limiting the Earth’s warming to 1.5 degrees Celsius above temperatures seen in the late 19th century. It had been widely assumed that this stringent target would prove unachievable, but the new study would appear to give us much more time to act if we want to stay below it.
by Arthur Viterio, 2016, in J Earth Science Climate Change
Earth’s climate is a remarkably “noisy” system, driven by scores of oscillators, feedback mechanisms, and radiative forcings. Amidst all this noise, identifying a solitary input to the system (i.e., HGFA MAG4/6 seismic activity as a proxy for geothermal heat flux) that explains 62% of the variation in the earth’s surface temperature is a significant finding.
by Cédric Moro, 18 septembre 2017 in Mythes,Mancies&Mathématiques
Que n’a-t-on pas entendu dans une partie de la presse et dans les déclarations à chaud de scientifiques et d’experts du climat sur l’uragan Irma. C’était du jamais vu, du jamais mesuré, d’une puissance inégalée, Europe 1 allant jusqu’à parler « du plus important de l’histoire climatologique ». Des eaux extraordinairement chaudes devaient expliquer son intensité effroyable (sous-entendu : Irma, c’est la faute au réchauffement), ses vents destructeurs records, son diamètre exceptionnel, ses pluies diluviennes, son raz de marée démesuré, son intensification inouïe ou ses dégâts hors normes…
by Javier, September 15, 2017, in Judith Curry Climate Etc.
The existence of a 1500-year climatic cycle during the Holocene, related to the glacial Dansgaard-Oeschger cycle, is a matter of intense debate. However, by introducing precise timing requirements it can be shown that the 1500-year cycle displayed in Northern Hemisphere glacial records is also observed in Holocene records from all over the world.
The cycle is most prominently displayed in oceanic subsurface water temperatures, Arctic atmospheric circulation, wind deposits, Arctic drift ice, and storminess records.
La géologie, une science plus que passionnante … et diverse
