Archives par mot-clé : Extreme events

A Critique of the Fourth National Climate Assessment

by Robert W. Endlich, December 18, 2018 in CAtmSciForum


In describing the errors in the Fourth National Climate Assessment, ‘NCA4’, I’ll use the words from the Executive Summary which purport to link climate changes in the USA to global climate change.

The first claim, “The last few years have also seen record-breaking, climate-related weather extremes,“ is shown to be false, simply by examining climate records, some from the National Climate Data Center.

Tornadoes have been decreasing over the past six decades as temperatures moderate from the significant cooling of the 1940s to 1970s.  As a basic knowledge of meteorology teaches, it is the pole to equator temperature difference that drives the intensity of cold season storms and especially the spring-season storms which bring the extremely strong tornado outbreaks.

Figure 1.  Annual count of strong to violent tornadoes from 1954-2014, showing a significant decrease of tornado activity the past 60 years, based on data from NOAAs Storm Prediction Center. [Note: This graphic replaces the original graphic that showed all tornadoes EF1 and stronger. Correction made 1/25/2019].

Extremes

by Judith Curry, June14, 2019 in WUWT


Politics versus science in attributing extreme weather events to manmade global warming.

If you follow me on twitter, you may have noticed that I was scheduled to testify before the House Oversight and Reform Committee on Jun 12 [link].  The subject of the Hearing is Contending with Natural Disasters in the Wake of Climate Change.

Late on Jun 10, I received an email telling me that the Hearing is postponed (as yet unscheduled).  Apparently the Committee finds it more urgent to have a Hearing related to holding the Attorney General and Secretary of Commerce in contempt of Congress [link].  Interesting to ponder that Congressional procedural issues are deemed to be more important than Climate Change.

So I spent all last week working on my testimony (which is why there have been no new blog posts).  I hope the Hearing will eventually happen (Michael Mann is also scheduled to testify).

Hurricanes and climate change constitute a major portion of my testimony.  You may recall my recent series  on Hurricanes & climate change [link].  Specifically with regards to detection and attribution, my bottom line conclusion was:

“In summary, the trend signal in hurricane activity has not yet had time to rise above the background variability of natural processes. Manmade climate change may have caused changes in hurricane activity that are not yet detectable due to the small magnitude of these changes compared to estimated natural variability, or due to observational limitations. But at this point, there is no convincing evidence that manmade global warming has caused a change in hurricane activity.”

Roy Spencer: Why so many tornadoes this year? It’s not what AOC, Bernie Sanders (or maybe even you) think

by Charles the moderator, May 29, 2019 in WUWT


By Roy Spencer | Fox News

Progressive politicians like Al Gore, Sen. Bernie Sanders, I-Vt., and Rep. Alexandria Ocasio-Cortez, D.N.Y., don’t hesitate to blame any kind of severe weather – even if it is decreasing over time – on global warming.

With the devastating Dayton, Ohio tornadoes fresh on our minds, it is useful to examine exactly why (modest) global warming has produced fewer – not more – of such events.

The simple answer is that tornado formation requires unusually cool air.

Very few thunderstorms produce tornadoes. In the hot and humid tropics, they are virtually unheard of. The reason why is that (unlike hurricanes) tornadoes require strong wind shear, which means wind speed increasing and changing direction with height in the lower atmosphere.

These conditions exist only when a cool air mass collides with a warm air mass. And the perfect conditions for this have existed this year as winter has refused to lose its grip on the western United States. So far for the month of May 2019, the average temperature across the U.S. is close to 2 degrees Fahrenheit below normal.

Scientists Find No Human Impact On Extreme Rainfall Events In Southeastern Australia…Rather ENSO Related

by P. Gosselin, May 21, 2019 in NoTricksZone


A new study appearing in the Journal of Weather and Climate Extremes titled “Historical extreme rainfall events in southeastern Australia” – led by LindenAshcroft, School of Earth Sciences, University of Melbourne – shows that even more extreme weather in terms of rainfall existed before 1900 in Melbourne, Sydney and Adelaide.

No real trend when examining Sydney, Australia data going back 178 years. Image: Ashcroft et al 2019.

Moreover, the authors found a “moderate and relatively stable relationship between El Niño–Southern Oscillation (ENSO) and annual variations of total rainfall and the number of raindays.”

40-Year Meteorologist Says Public “Being Fed Bill Of Goods” By Climate Alarmists On Hurricanes, Tornadoes

by P. Gosselin, April 14, 2019 in NoTricksZone


At the latest Saturday Summary at Weatherbell Analytics, Joe Bastardi, a well-known 40-year veteran of meteorology, looks at tornadoes and hurricanes.

Although many meteorologists and climatologists confirm that there is no data suggesting global warming is causing more frequent and intense tornado and hurricane activity, there is a small but influential alarmist group who claim otherwise. And it’s no surprise who the click-baiting media parrot at maximum volume.

Landfalling hurricanes downward trend

At the 5:45 mark, Joe presents a chart depicting the frequency of US landfalling hurricanes since 1900:

 

BBC Repeat Fake Extreme Weather Disaster Claims

by P. Homewood, February 9, 2019 in NotaLotofPeopleKnowThat


Politicians and policymakers have failed to grasp the gravity of the environmental crisis facing the Earth, a report claims.

The think-tank IPPR says human impacts have reached a critical stage and threaten to destabilise society and the global economy.

Scientists warn of a potentially deadly combination of factors.

These include climate change, mass loss of species, topsoil erosion, forest felling and acidifying oceans.

The report from the centre-left Institute for Public Policy Research says these factors are “driving a complex, dynamic process of environmental destabilisation that has reached critical levels.

“This destabilisation is occurring at speeds unprecedented in human history and, in some cases, over billions of years.”

The IPPR warns that the window of opportunity to avoid catastrophic outcomes is rapidly closing.

The authors urge three shifts in political understanding: on the scale and pace of environmental breakdown; the implications for societies; and the subsequent need for transformative change.

​They say since 2005, the number of floods across the world has increased by 15 times, extreme temperature events by 20 times, and wildfires seven-fold.

At least climate change features in policy discussions, they say – but other vitally important impacts barely figure.

What issues are being under-played?

New GWPF Paper Shows Hurricanes Are Not Getting Worse

by P. Homewood, January 14, 2019 in NotaLotofPeopleKnowThat


https://www.thegwpf.org/content/uploads/2019/01/Homewood-Hurricanes.pdf

I am pleased to report that the GWPF have now published my latest paper on hurricane trends.

It demonstrates that, contrary to popular myth, hurricanes are not getting more frequent or more powerful.

The paper is based throughout on official data, scientific papers and IPCC reports.

Here is the Executive Summary:

Another Climate Propaganda Story Promoting the Normal as Abnormal

by Dr Tim Ball, January 8, 2019 in WUWT


Other stories focus on a pattern or change in a pattern again with the idea that it is new or abnormal. Headlines like this one from 2012, “Why have there been more tornadoes than usual this year?” Often, they are suggestive such as this 2017 New York Times story. “The 2017 Hurricane Season Really Is More Intense Than Normal.” When you read the story, you find, as is usually the case, that the caveats at the end indicate it is not unusual. The problem is the headline already set the pattern in the public mind.

U.S. Media Bans Scientific Dissent – Claim Wildfires, Floods, Droughts, Hurricanes Are Human-Controlled

by K. Richard, January 7, 2019 in NoTricksZone


NBC News’ Chuck Todd recently asserted that we humans can control the climate and the frequency or intensity of extreme weather events (hurricanes, floods, droughts) and disasters (wildfires) with our CO2 emissions. He has declared the science is “settled” on this point and therefore no “denier” is allowed on his Meet the Press program. But Todd and the members of his panel have recited claims that are contravened by observational evidence and scientific publications.

Kerala Floods “Likely Due To Climate Variability, Not AGW”–New Study

by P. Homewood, January 5, 2019 in NotaLotofPeopleKnowThat


Since there is no increase in mean and extreme precipitation in Kerala over the last six decades, the extreme event during August 2018 is likely to be driven by anomalous atmospheric conditions due to climate variability rather anthropogenic climate warming. The severity of the Kerala flood of 2018 and the damage caused might be affected by several factors including land use/ land cover change, antecedent hydrologic conditions, reservoir storage and operations, encroachment of flood plains, and other natural factors. The impacts of key drivers (anthropogenic and natural) on flood severity need to be established to improve our understanding of floods and associated damage.

http://www.geosocindia.org/index.php/jgsi/article/view/137443

Extreme weather is the most likely and severe threat facing humanity!

by P. Homewood, November 8, 2018 in NotaLotofPeopleKnowThat


My very first foray into climate blogging was an analysis of extreme weather events in 1971. (I wrote it in 2011, so it was not a cherrypicked year, merely a nice round 40 years before.)

I won’t bore you with it again, as it was basically just a very long list. You can see it here though.

But here is a summary, which goes to show that extreme weather is the norm, not the exception:

 

The rise of Climate superstition: Droughts, heatwaves, random noise is “proof” of anything you like

by JoNova, August 7, 2018


All around the world the climate druids are at work.

Show me the error bars

Once upon a time a scientist talked about thirty year trends and anachronistic things like “confidence intervals”. Now, thanks to the discovery of Unscience, any noisy, random short data is fair game to be declared undeniable climate change. Periods of flooding also qualify, as do periods of nice weather, though strangely no one mentions those. Where are the headlines? If climate change caused drought on the East Coast of Australia, it’s also causing average rain and good crops in Western Australia.

In terms of scientific data analysis we don’t get that many droughts or six-day-August-heatwaves to analyze. They’re complex phenomena caused by multiple factors and we only have short records. This makes them ideal to be oversold to hapless folk as a “sign” of climate change.

(…)

Weather-related Natural Disasters: Should we be concerned about a reversion to the mean?

by Prof. Roger Pielke Jr, July 31, 2017, University of Colorado Boulder


The world is presently in an era of unusually low weather disasters. This holds for the weather phenomena that have historically caused the most damage: tropical cyclones, floods, tornadoes and drought. Given how weather events have become politicized in debates over climate change, some find this hard to believe. Fortunately, government and IPCC (Intergovernmental Panel on Climate Change) analyses allow such claims to be adjudicated based on science, and not politics.  Here I briefly summarize recent relevant data.

US Climate Report Edits Out Highly Embarrassing Section

by Paul Homewood, August 10, 2017, in WUWT


I mentioned in my previous post that the latest draft climate report, published in June, had seemingly left out a rather embarrassing table from the Executive Summary, one that had previously been written into the Third Draft, published last December.

As the link to the Third Draft had disappeared from the NYT, I could not show it.

However, Michael Bastasch, writing over at WUWT, did have the link, so we can now compare the relevant sections.

See also here