Landmark 2013 IPCC Report: 95% Chance Most of Global Warming is Human-Caused

By: Dr. Jeff Masters , 10:50 AM GMT on September 27, 2013

"Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased." Thus opens the landmark 2013 Intergovernmental Panel on Climate Change (IPCC) report issued today. Working without pay, hundreds of our most dedicated and talented climate experts have collaborated over a six-year period to create the most comprehensive and authoritative scientific document on climate change ever crafted. The first 31 pages of what will be a 4,000-page tome was released this morning after an all-night approval session that stretched until 6:30 this morning in Stockholm, Sweden. This "Summary For Policymakers" lays out a powerful scientific case that significant climate change with severe impacts is already occurring, humans are mostly responsible, the pace of climate change is expected to accelerate, and we can make choices to cut emission of carbon dioxide and other heat-trapping gases that will limit the damage.

Q: How much has the planet warmed, and what has caused the warming?
The report documents that Earth's surface temperature warmed by 0.85°C (1.5°F) between 1880 - 2012. Two-thirds of this warming (0.6°C, 1.1°F) came after 1950. Human-emitted heat-trapping gases likely were responsible for 0.5 - 1.3°C of this post-1950 warming, while human-emitted aerosol particles reflected away sunlight and likely caused cooling (-0.6° - 0.1°C change in temperature.) Climate change due to variations in solar energy, volcanic dust, and natural sources of heat-trapping greenhouse gases were likely responsible for a small -0.1° - 0.1°C change in temperature since 1950. The sun was in a cool phase between 1978 - 2011, and the report estimates that lower solar output cooled Earth's climate slightly during this period. The influence of cosmic rays on climate over the past century was to weak to be detected, they said. In short, the report shows little support for a significant natural component to global warming since 1950. In fact, natural effects may well have made Earth cooler than it otherwise would have been. The report says that "The best estimate of the human-induced contribution to warming is similar to the observed warming over this period." In other words, close to 100% of the observed warming is due to humans.


Figure 1. The changing view of the IPCC's assessment reports on the human contribution to climate change.

Q: How have the IPCC reports changed through time?
1990: The report did not quantify the human contribution to global warming.

1995: "The balance of evidence suggests a discernible human influence on climate."

2001: Human-emitted greenhouse gases are likely (67-90% chance) responsible for more than half of Earth's temperature increase since 1951.

2007: Human-emitted greenhouse gases are very likely (at least 90% chance) responsible for more than half of Earth's temperature increase since 1951.

2013: Human-emitted greenhouse gases are extremely likely (at least 95% chance) responsible for more than half of Earth's temperature increase since 1951. This is the same confidence that scientists have in the age of the universe, or that cigarettes are deadly, according to an excellent AP article published this week by Seth Borenstein.

Q: Did the new report change the plausible range of global warming?
A. Yes. The "climate sensitivity" is defined as how much the planet would warm if the amount of atmospheric CO2 doubled. A variety of studies have arrived at very different estimates of the exact CO2 sensitivity of the climate, and the 2007 IPCC report gave a range of the most plausible values: 2 to 4.5ºC, with 3ºC deemed the most likely value. Recent research indicates that a sensitivity as low as 1.5ºC may be possible, so the IPCC widened the range of the most plausible values: 1.5 to 4.5ºC. The new lower limit of 1.5ºC is a best-case scenario that appears no more likely than the high end of 4.5ºC. Furthermore, even the lowest sensitivity scenario would not negate the need for emissions reductions. Current trends show that emissions are on track to increase far beyond doubling, which would create dangerous temperature rise even in a low-sensitivity climate. (Note that they give a small but worrisome possibility--0 to 10% chance--that the climate could warm by more than 6ºC for a doubling of CO2.)


Figure 2. Average of NASA's GISS, NOAA"s NCDC, and the UK Met Office's HadCRUT4 monthly global surface temperature departures from average, from January 1970 through November 2012 (blue), with linear trends applied to the time frames Jan '70 - Oct '77, Apr '77 - Dec '86, Sep '87 - Nov '96, Jun '97 - Dec '02, Nov '02 - Nov '12. Climate change skeptics like to emphasize the shorter term fluctuations in global temperatures (blue lines) and ignore the long-term climate trend (red line.) The global surface temperature trend from January 1970 through November 2012 (red line) is +0.16°C (+0.29°F) per decade. Image credit: skepticalscience.com.

Q: What does the IPCC say about the "speed bump" in surface global warming over the past 10 - 15 years?
Much attention has been given in the press to the fact that the rate of surface warming over the past fifteen years has been slower than during previous decades. The report notes that due to natural variability, trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends. As one example, the rate of warming over the past 15 years (1998–2012) of 0.05 °C per decade, which begins with a strong El Niño, is smaller than the rate calculated since 1951 of 0.12 °C per decade. However, the recent slow-down in surface warming is likely to be a mere "speed bump" on the highway of global warming, caused by natural variability. We have seen such "speed bumps" before, as well as short, sharp downhill stretches where surface warming speeds up. For example, climate scientist Stefan Rahmstorf writes at realclimate.org that "the warming trend of the 15-year period up to 2006 was almost twice as fast as expected (0.3°C per decade), and (rightly) nobody cared. We published a paper in Science in 2007 where we noted this large trend, and as the first explanation for it we named “intrinsic variability within the climate system”. Which it turned out to be." Physics demands that the massive amounts of heat-trapping carbon dioxide humans have dumped into the atmosphere must cause significant warming, but the chaotic complexity of the system is expected to obscure the magnitude of the long-term trend on time scales of a few years to a decade. The attention being to this latest "speed bump" on the highway of global warming is a direct result of a well-funded PR effort by the fossil fuel industry. One has to look at the total warming of the atmosphere, oceans, land, and ice to judge the true progress of global warming, not just the surface temperature. There has been no slowdown in total global warming when we regard this entire system, as I argued in a post earlier this year. More than 90% of the energy of global warming goes into the oceans, and the reason for the relative lack of surface warming this decade is that more heat than usual is being stored in the oceans. That heat will be released to the atmosphere at some point, removing the "speed bump".

The new IPCC report says that there is medium confidence that the "speed bump" in surface warming is due in roughly equal measure to natural multi-year unpredictable variability in the weather, and to changes in the amount of sunlight reaching the surface due to volcanic eruptions and the downward phase of the current solar cycle. Most of the climate models do not reproduce this lower surface warming rate during the past 10 - 15 years. There is medium confidence that this difference between models and observations is due to natural climate variability that is impossible to predict (for example, the El Niño/La Niña cycle), with possible contributions from the models' inadequate handling of volcanic eruptions, changes in solar output, and changes in light-reflecting aerosol particles, and, in some models, a too-strong response to heat-trapping gases. For an explanation of why arguments about the global warming “slowdown” are misleading and should not offer any consolation, see this explainer from Skeptical Science and this one from the Union for Concerned Scientists.

Q: What does the IPCC say about drought?
A: Drought and reduction in water availability due to decreased mountain snow and ice is the greatest threat civilization faces from climate change, since it attacks the two things we need to live--water and food. Unfortunately, the report makes no mention of drought in the text, and we will have to wait for the March 2014 release of the "impacts" portion of the report to hear more about the threat drought poses to society. Today's report does mention drought in one of their two tables, giving “low confidence”--a 20% chance--that we have already observed a human-caused increase in the intensity and/or duration of drought in some parts of the world. This is a reduction in confidence from the 2007 report, which said that it was more likely than not (greater than 50% chance.) However, the forecast for the future is the same as in the 2007 report: we are likely to see dry areas get dryer due to human-caused climate change by 2100. In particular, there is high confidence (80%) in likely surface drying in the Mediterranean, Southwest U.S., and Southern Africa by 2100 in the high-end emissions scenario (RCP8.5), in association with expected increases in surface temperatures and a shift in the atmospheric circulation that will expand the region of sinking air that creates the world's greatest deserts.

Q: What does the IPCC say about sea level rise?
A: Global average sea level has risen 7.5" (19 cm) since 1901. Sea level has accelerated to 1.5" (3.2 cm) per decade over the past 20 years--nearly double the rate of rise during the 20th century. The report projects that sea level will rise by an extra 0.9 - 3.2' (26 to 98 cm) by 2100. While the maximum sea level rise expected has gone up since the 2007 report, when the IPCC did not even consider melt from Greenland and Antarctica because of the primitive state of glacier science then, the new upper bound (3.2') is still is a very conservative number. IPCC decided not to include estimates from at least five published studies that had higher numbers, including two studies with rises of 2 meters (6.6 feet.) This is in contradiction to NOAA's December 2012 U.S. National Climate Assessment Report, which has 6.6 feet (2.0 meters) as its worst-case sea level rise scenario for 2100. Even this number may be too low; at a presentation Thursday in New York City for Climate Week, glaciologist Dr. Jason Box, who knows as much about Greenland's ice sheets as any person alive, explained that Greenland's contribution to global sea level rise doubled over the past ten years. If Greenland's melt rate continues to double every ten years until 2100, Greenland alone will contribute 4.6' (1.4 meters) of global sea level rise, he said. If the doubling time becomes every nine years, then Greenland will cause 16.4' (5 meters) of sea level rise by 2100. His best-guess number for global sea level rise by 2100 is 4.7' (1.5 meters), but warns that our models used to predict melting of ice of Greenland have large unknowns.

Long-term sea level rise is expected to be much greater. The IPCC report states with "very high confidence" that 119,000 - 126,000 years ago, during the period before the most recent ice age, sea levels were 16 - 33 feet (5 - 10 meters) higher than at present. Melting of Greenland "very likely" contributed 1.4 - 4.3 meters of this rise, with additional contributions coming from Antarctica. Temperatures at that time weren't more than 2°C warmer than "pre-industrial" levels during that period. Two of the four scenarios used for the report project we will exceed 2°C of warming by 2100, with "high confidence", raising the possibility that we could see sea level rises of many meters over time scales of 1,000 years or so. The report expects sea level rise reach 3.3 - 9.8' (1 - 3 meters) by 2300, assuming CO2 levels rise above 700 ppm (close to what the higher-end RCP6.0 scenario prescribes.)

Q: What does the IPCC say about ocean acidity?
A: The world's oceans have seen a 26% increase in acidity since the Industrial Revolution, as the average pH has dropped from 8.2 to 8.1. Under all report scenarios, the acidification of the world's oceans will increase, with the pH falling by another 0.06 - 0.32 units. According to a 2012 study in Science, the current acidification rate is likely the fastest in 300 million years, and "may have severe consequences for marine ecosystems."

Q: How about hurricanes?
A: The new report gives “low confidence”--a 20% chance--that we have observed a human-caused increase in intense hurricanes in some parts of the world. This is a reduction from the 2007 report, which said that it was more likely than not (greater than 50% chance.) The IPCC likely took note of a landmark 2010 review paper, "Tropical Cyclones and Climate Change", authored by ten top hurricane scientists, which concluded that the U.S. has not seen any long-term increase in landfalling tropical storms and hurricanes, and that "it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes." The 2013 IPCC report predicts that there is a greater than 50% chance (more likely than not) that we will see a human-caused increase in intense hurricanes by 2100 in some regions; this is a reduction from the 2007 report, which said this would be likely (66% chance or higher.)

Q: How about extreme weather events?
"Changes in many extreme weather and climate events have been observed since about 1950. It is very likely that the number of cold days and nights have decreased and the number of warm days and nights has increased on the global scale. It is likely that the frequency of heat waves has increased in large parts of Europe, Asia, and Australia. There are likely more land regions where the number of heavy precipitation events has increased than where it has decreased. The frequency or intensity of heavy precipitation events has likely increased in North America and Europe." The report made no mention of tornadoes and severe thunderstorms, since the uncertainties of how they have behaved in the past and how climate change might affect them in the future are too great.

Q: What does the IPCC say about a "Day After Tomorrow" scenario?
A: In the disaster movie "The Day After Tomorrow", the Atlantic Meridional Overturning Circulation (AMOC)--the ocean current system of which the Gulf Stream Current is a part of--collapses, causing a rapid and extreme change in climate. A collapse of the AMOC is very unlikely (0 - 10% chance) before 2100 according to the report, but cannot be ruled out beyond the 21st century. A weakening of the AMOC by about 11 - 34% by 2100 is expected in the moderate RCP4.5 scenario, where CO2 levels reach 538 ppm in 2100. However, these odds assume that Greenland will dump a relatively modest amount of fresh water into the North Atlantic by 2100. If the higher-end sea level rise estimates that the IPCC did not consider as plausible come true, the AMOC will likely slow down much more, with a higher chance of collapse this century. No slow-down in the AMOC has been observed yet, according to the report.

Commentary
As I read though the report, digesting the exhaustive list of changes to Earth's atmosphere, oceans, and ice that have occurred over the past few decades, I was struck by how the IPCC report reads like lab results from a sick hospital patient. The natural systems that civilization depends upon to thrive have been profoundly disturbed, and the forecast for the future reads like a medical diagnosis for an overweight smoker with a heart condition: unless the patient makes major lifestyle changes, the illness will grow far worse, with severe debilitation or death distinct possibilities. We can and we must make the huge effort to turn things around. Oil and natural gas are the energy technologies of the 20th century. Coal is the energy technology of the 19th century. We have countless innovative and dedicated people ready to move us to the energy technology of the 21st century; I heard three of them speak last night at the Climate Week event I am at, and they really gave me some needed hope that we can turn things around. We must elect new leaders and pressure our existing leaders to take the strong actions needed to advance us into a new, 21st century energy economy. You can all help make it so!

Jeff Masters

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1329. LAbonbon
2:38 PM GMT on September 28, 2013
This previous blog by Dr M (from April 10, 2013) discusses some of the pre-season forecasts, and why the forecasts were given as they were.

Active 2013 Atlantic Hurricane Season Expected by CSU, TSR, and WSI


Member Since: June 26, 2013 Posts: 0 Comments: 4158
1328. CybrTeddy
2:37 PM GMT on September 28, 2013
Quoting 1320. ncstorm:
Climate change is likely to bring more walloping storms to the United States. Citing several climate factors, NOAA predicts that the 2013 Atlantic hurricane season will be busier than normal. Among the factors at play in the atmosphere, scientists can connect climate change to the warmer water and atmospheric temperatures in the Caribbean and Atlantic, which strengthen storms and raise their rainfall potential. Additionally, rising sea levels caused by climate change will increase storm surges and the destructiveness of hurricanes.



Don't you love misleading headlines? CSU and TSR never used climate change as a support behind an active season, they used climate factors such as SST anomalies and the ENSO to determine that. If so, why didn't they claim climate change to make their 2012 predictions well above average? The same factors were in place then.
Member Since: July 8, 2005 Posts: 259 Comments: 25950
1327. Neapolitan
2:37 PM GMT on September 28, 2013
Quoting 1313. ncstorm:


I saw it posted here many times..but let me check and see If I can find it..

care to comment why GW was supposed to fuel stronger hurricanes for this upcoming season?
Again, I'll do so just as soon as you and/or Tampa Spin show me where any "experts" said GW would lead to an above average year. Now, that's the third time I've asked for that this morning. Givewn that I've yet received no answer, I'm going to assume 'tis nothing but a straw man. Thanks!
Member Since: November 8, 2009 Posts: 4 Comments: 15191
1326. Gearsts
2:37 PM GMT on September 28, 2013
Quoting 1324. GTstormChaserCaleb:
Of the 3 systems we are tracking in the Atlantic, 2 are accompanied by an ULL (96L and the one off the East Coast).

Looks like late october with all that shear.
Member Since: August 2, 2010 Posts: 0 Comments: 5903
1325. Xyrus2000
2:36 PM GMT on September 28, 2013
Quoting 1292. Abacosurf:
Just wait for the next "landmark review paper" It will change again...and again...and again.

So why did the percentage drop from 50% to 20%....

Because of a paper written?? Pathetic.
Maybe this one was not "peer reviewed" enough.


That's how science works. You do some research. You get it reviewed. You publish your results. Someone comes along and improves upon that research. They get it reviewed. They publish. So on and so forth.

There can be any number of reasons that new research can change previous results. Better data. Better physical models. Better algorithms. Better analysis. It happens all the time across all the sciences.

Science is an iterative process of building upon other's research. That's how ALL science works, from genetics to astrophysics.

And to clarify, what the changes in percentage are based on whether or not we have already observed effects, not whether or not the projections themselves will eventually come about.
Member Since: October 31, 2009 Posts: 0 Comments: 2568
1324. GTstormChaserCaleb
2:34 PM GMT on September 28, 2013
Of the 3 systems we are tracking in the Atlantic, 2 are accompanied by an ULL (96L and the one off the East Coast).

Member Since: June 30, 2013 Posts: 12 Comments: 10603
1323. Naga5000
2:33 PM GMT on September 28, 2013
1322. BillDietrich
2:33 PM GMT on September 28, 2013
Typo in the article: "over the past century was to weak to be detected".
Member Since: September 27, 2013 Posts: 0 Comments: 0
1321. Gearsts
2:31 PM GMT on September 28, 2013
SLU and CaribBoy if you guys want we should move to the philippines ;) Weather there is much more interesting i think.
Member Since: August 2, 2010 Posts: 0 Comments: 5903
1319. redwagon
2:30 PM GMT on September 28, 2013
Quoting 1303. GatorWX:


I wish Gro was here to post those animated pouch tracks...
Member Since: August 4, 2007 Posts: 0 Comments: 3649
1318. Skyepony (Mod)
2:27 PM GMT on September 28, 2013
Just started raining again.. There's a bit of rain falling out of that orange air this morning..

Member Since: August 10, 2005 Posts: 412 Comments: 43674
1317. SLU
2:27 PM GMT on September 28, 2013
Quoting 1314. hydrus:
One can always pull the stakes and find a spot in the Philippines..You will get your fill of the biggest and baddest.:)

Like 79,s Tip..
http://upload.wikimedia.org/wikipedia/commons/7/7 a/Typhoon_tip_peak.jpg
58,s Ida...Notice the thunderstorms literally being sucked into the center of this monster. 4th strongest ever.

Vanessa ranked 7th at 190 mph..

Forrest..Super Typhoon Forrest was one the fastest intensifying tropical cyclones ever recorded with its pressure dropping 90 mbar in just under 24 hours. Its maximum winds explosively went from 75 miles per hour (121 km/h) to 173 miles per hour (278 km/h) in just a day.



We live in the wrong part of the world ...
Member Since: July 13, 2006 Posts: 13 Comments: 6228
1316. RGVtropicalWx13
2:26 PM GMT on September 28, 2013
I wouldn't say less than 10% either. It'll happen. Got to get that 2013 shell people. Snap out of it.
Member Since: May 30, 2013 Posts: 0 Comments: 567
1315. SLU
2:26 PM GMT on September 28, 2013
Member Since: July 13, 2006 Posts: 13 Comments: 6228
1314. hydrus
2:26 PM GMT on September 28, 2013
Quoting 1300. SLU:


So sad to see them become extinct. :(
One can always pull the stakes and find a spot in the Philippines..You will get your fill of the biggest and baddest.:)

Like 79,s Tip..

58,s Ida...Notice the thunderstorms literally being sucked into the center of this monster. 4th strongest ever.

Vanessa ranked 7th at 190 mph..

Forrest..Super Typhoon Forrest was one the fastest intensifying tropical cyclones ever recorded with its pressure dropping 90 mbar in just under 24 hours. Its maximum winds explosively went from 75 miles per hour (121 km/h) to 173 miles per hour (278 km/h) in just a day.
Member Since: September 27, 2007 Posts: 1 Comments: 28034
1313. ncstorm
2:25 PM GMT on September 28, 2013
Quoting 1304. Neapolitan:
Sorry for your continued confusion in this matter. But it's been explained many times before, so I'm certain you can find the answers you seek with a mere modicum of honest searching.

So far as the rest, I was responding specifically to Tampa Spin's claim that "experts" had predicted this year would be above average. Do you know where s/he might've seen that?


I saw it posted here many times..but let me check and see If I can find it..

care to comment why GW was supposed to fuel stronger hurricanes for this upcoming season?
Member Since: August 19, 2006 Posts: 13 Comments: 18134
1312. SLU
2:25 PM GMT on September 28, 2013

Member Since: July 13, 2006 Posts: 13 Comments: 6228
1311. Skyepony (Mod)
2:24 PM GMT on September 28, 2013
Quoting 1307. GatorWX:


Humidity is 80% right now here in swFL.


East Central FL I've got 99%. Had a quick 0.51" downpour this morning from the little perturbed area of clouds hanging around Cape Canaveral..
Member Since: August 10, 2005 Posts: 412 Comments: 43674
1310. GatorWX
2:24 PM GMT on September 28, 2013
Quoting 1305. GTstormChaserCaleb:
Global Warming didn't only imply that extreme weather would lead to more hurricanes, it implied to other extremities like Drought, Flooding, Wildfires, and Blizzards, and we are talking about on a Global scale, not just what's going on in the US either. Let's see last year we had Superstorm Sandy and this year we have had the Colorado flooding and droughts in Brazil. Now one could use a better argument and that would be has Arctic Ice melt over the recent years shown to limit activity in the Atlantic Ocean this year? Think about why ULL's form, from mid-latitude systems, think about what causes mid-latitude systems to form from the Jet Stream, think about where the Jet Stream originates from? The Arctic and North Pole. Now has high pressure ridging dominated the Arctic region this summer and has there also been persistent troughiness on the East Coast this year? Happen to notice most every time a system tries to get going there happens to be an ULL nearby? So why is that? Is because of the reasons I just explained?

Certainly this is not an El-Nino year, so has a point been made? That even in non-El-Nino year, hurricane season can be inactive? How about in 2004 another extreme an El-Nino year that was active? See this is what makes the weather so fascinating because there is so much aspects involved and there is still lots of studies being done on the weather. You have to look at the low levels, the mid levels, the upper levels, the stratosphere, the troposphere, conditions have to be ripe in all of those levels, then you have to look at sea surface temperatures, TCHP, SAL, Vertical and Horizontal Instability, High Pressure and Low Pressure, Trade Winds, Prevailing Westerlies, African Easterly Waves, African Easterly Jet, ITCZ, TUTT's, and Airmass.

Teleconnection, is the Indian Ocean active because usually when they are the Atlantic is active. Man I could go on and on, but there is still lots to be learn and the effects that climate change are having on these weather systems is one that will be a subject to study for many years to come. Good luck to all who are pursuing a career in Meteorology or one of the Geosciences and may the force be with you.


A weaker jet stream and stronger secondary upper level features; that's my theory.
Member Since: January 1, 2008 Posts: 0 Comments: 4274
1309. pottery
2:22 PM GMT on September 28, 2013
Quoting Neapolitan:
Sorry for your continued confusion in this matter. But it's been explained many times before, so I'm certain you can find the answers you seek with a mere modicum of honest searching.

So far as the rest, I was responding specifically to Tampa Spin's claim that "experts" had predicted this year would be above average. Do you know where s/he might've seen that?

Correct me if I'm wrong here, but I thought the average was 12, and the overall predicted average (by the expert weather forecasters) was for 16.
Member Since: October 24, 2005 Posts: 0 Comments: 26906
1308. Skyepony (Mod)
2:21 PM GMT on September 28, 2013
RAMMB has a floater on the cold core system east of the Bahamas. Gfs keeps it cold core. CMC warms it up some as it moves north. Click pic to see shear working it.

Member Since: August 10, 2005 Posts: 412 Comments: 43674
1307. GatorWX
2:21 PM GMT on September 28, 2013
Quoting 1290. Patrap:


Most is at the mid levels, so squeaking out that Rain is not uncommon, happened here last weekend .


Humidity is 80% right now here in swFL.

Member Since: January 1, 2008 Posts: 0 Comments: 4274
1306. LAbonbon
2:20 PM GMT on September 28, 2013
Member Since: June 26, 2013 Posts: 0 Comments: 4158
1305. GTstormChaserCaleb
2:19 PM GMT on September 28, 2013
Global Warming didn't only imply that extreme weather would lead to more hurricanes, it implied to other extremities like Drought, Flooding, Wildfires, and Blizzards, and we are talking about on a Global scale, not just what's going on in the US either. Let's see last year we had Superstorm Sandy and this year we have had the Colorado flooding and droughts in Brazil. Now one could use a better argument and that would be has Arctic Ice melt over the recent years shown to limit activity in the Atlantic Ocean this year? Think about why ULL's form, from mid-latitude systems, think about what causes mid-latitude systems to form from the Jet Stream, think about where the Jet Stream originates from? The Arctic and North Pole. Now has high pressure ridging dominated the Arctic region this summer and has there also been persistent troughiness on the East Coast this year? Happen to notice most every time a system tries to get going there happens to be an ULL nearby? So why is that? Is because of the reasons I just explained?

Certainly this is not an El-Nino year, so has a point been made? That even in non-El-Nino year, hurricane season can be inactive? How about in 2004 another extreme an El-Nino year that was active? See this is what makes the weather so fascinating because there is so much aspects involved and there is still lots of studies being done on the weather. You have to look at the low levels, the mid levels, the upper levels, the stratosphere, the troposphere, conditions have to be ripe in all of those levels, then you have to look at sea surface temperatures, TCHP, SAL, Vertical and Horizontal Instability, High Pressure and Low Pressure, Trade Winds, Prevailing Westerlies, African Easterly Waves, African Easterly Jet, ITCZ, TUTT's, and Airmass.

Teleconnection, is the Indian Ocean active because usually when they are the Atlantic is active. Man I could go on and on, but there is still lots to be learn and the effects that climate change are having on these weather systems is one that will be a subject to study for many years to come. Good luck to all who are pursuing a career in Meteorology or one of the Geosciences and may the force be with you.
Member Since: June 30, 2013 Posts: 12 Comments: 10603
1304. Neapolitan
2:19 PM GMT on September 28, 2013
Quoting 1291. ncstorm:


not GW but climate change but I cant keep the two straight..
Sorry for your continued confusion in this matter. But it's been explained many times before, so I'm certain you can find the answers you seek with a mere modicum of honest searching.

So far as the rest, I was responding specifically to Tampa Spin's claim that "experts" had predicted this year would be above average. Do you know where s/he might've seen that?
Member Since: November 8, 2009 Posts: 4 Comments: 15191
1303. GatorWX
2:18 PM GMT on September 28, 2013
Member Since: January 1, 2008 Posts: 0 Comments: 4274
1302. GatorWX
2:15 PM GMT on September 28, 2013
Pretty close:

Member Since: January 1, 2008 Posts: 0 Comments: 4274
1301. SLU
2:15 PM GMT on September 28, 2013
Quoting 1278. CaribBoy:
Man... that's just pitiful.

.SYNOPSIS...SURFACE HIGH PRESSURE ACROSS THE CENTRAL ATLANTIC WILL REMAIN
THE DOMINANT WX FEATURE THROUGH THE END OF NEXT WEEK. TROPICAL
WAVE APPROACHING THE LESSER ANTILLES MAY WEAKEN SIGNIFICANTLY
BEFORE REACHING THE EASTERN CARIBBEAN
.


&&

.DISCUSSION...ISOLATED SHOWERS WERE OBSERVED ACROSS THE LOCAL
WATERS OVERNIGHT WITH SOME THUNDERSTORMS ACROSS THE ATLANTIC
WATERS AS WELL. WEATHER CONDITIONS ARE EXPECTED TO BE SIMILAR TO
THE LAST FEW DAYS...WHERE ISOLATED SHOWERS AND THUNDERSTORMS ARE
EXPECTED ACROSS THE NORTHWESTERN QUADRANT OF PUERTO RICO IN THE
AFTERNOON HOURS WHILE THE REST OF PUERTO RICO...AS WELL AS THE
U.S. VIRGIN ISLANDS...REMAIN WITH LITTLE TO NO WEATHER AND ABOVE
AVERAGE TEMPERATURES.


SOUTHEASTERLY WINDS WILL PREVAIL FOR THE NEXT FEW DAYS AND IT IS
NOT UNTIL MONDAY WHEN THE WINDS SHIFT A LITTLE BIT MORE TO THE
EAST. THESE VERY WARM TEMPERATURES THAT WE HAVE OBSERVED FOR THE
PAST FEW DAYS WILL LIKELY CONTINUE TODAY AND SUNDAY...AT THE VERY
LEAST...BUT WITH THE TROPICAL WAVE WEAKENING AS IT
APPROACHES
...ABOVE AVERAGE TEMPERATURES ARE QUITE POSSIBLE NEXT
WEEK AS WELL.


No hope anymore. 2013, please go away.


I feel like someone should draw a gun to 2013's head and pull the trigger for once and for all so we can both move on to our long and boring dry season CaribBoy.
Member Since: July 13, 2006 Posts: 13 Comments: 6228
1300. SLU
Quoting 1283. hydrus:
The latest addition to the endangered species list, The Atlantic hurricane..lol



So sad to see them become extinct. :(
Member Since: July 13, 2006 Posts: 13 Comments: 6228
Quoting 1280. PensacolaDoug:
Water vapor loop sure looks like the ncgom is closed for a while, probably the season.


I certainly hope that's the case :)
Member Since: June 26, 2013 Posts: 0 Comments: 4158
1298. SLU
Quoting 1279. hydrus:
Good morning Slu. It is only me harmless opinion, but I believe we will still get a major hurricane this year. Atmospheric conditions have been submarginal and a small window of better conditions should arise in the Central and Western Caribbean during the secondary peak. You have been here a long time, if a crow falls on my plate, I will still think of the fodder that taught me another lesson on the dynamic and sometimes unpredictable tropics..:)
'

LOL. Well the MJO is due in the WCAR by the 15th so that's our last and final chance 'til possibly August 2015 of seeing a decent major hurricane like we used to back in the good old days....
Member Since: July 13, 2006 Posts: 13 Comments: 6228
Quoting 1290. Patrap:


Most is at the mid levels, so squeaking out that Rain is not uncommon, happened here last weekend .


Yeah, I remember somebody in Baton Rouge saying it was pouring with 'no' moisture on WV.
Member Since: August 4, 2007 Posts: 0 Comments: 3649
1296. flcanes
Lets just face it.
Theoretically, the number of seasons like 1992 should increase, and the "big storms" will be getting stronger. Eventually the numbers will decrease so much that hurricanes may not form in the future. Of course, this is part wishful thinking.
Member Since: Posts: Comments:
1295. pottery
Quoting PensacolaDoug:
Water vapor loop sure looks like the ncgom is closed for a while, probably the season.

Looks that way.
Wondering what the Dry Season will bring in Jan-May.
It's been a very dry wet-season this year, and water may become an issue.
I've never known such a dry Aug-Sept. Worrying.
Member Since: October 24, 2005 Posts: 0 Comments: 26906
1294. ncstorm
Good Morning by the way..

Member Since: August 19, 2006 Posts: 13 Comments: 18134
1293. JLPR2


96L looking better, now it needs to sustain and expand its convection.
Member Since: Posts: Comments:
Quoting 1286. Patrap:
Q: How about hurricanes?
A: The new report gives %u201Clow confidence%u201D--a 20% chance--that we have observed a human-caused increase in intense hurricanes in some parts of the world. This is a reduction from the 2007 report, which said that it was more likely than not (greater than 50% chance.) The IPCC likely took note of a landmark 2010 review paper, "Tropical Cyclones and Climate Change", authored by ten top hurricane scientists, which concluded that the U.S. has not seen any long-term increase in landfalling tropical storms and hurricanes, and that "it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes." The 2013 IPCC report predicts that there is a greater than 50% chance (more likely than not) that we will see a human-caused increase in intense hurricanes by 2100 in some regions; this is a reduction from the 2007 report, which said this would be likely (66% chance or higher.)


What is phunny, is the rant is covered in Masters summary above.

LOL
Just wait for the next "landmark review paper" It will change again...and again...and again.

So why did the percentage drop from 50% to 20%....

Because of a paper written?? Pathetic.
Maybe this one was not "peer reviewed" enough.
Member Since: Posts: Comments:
1291. ncstorm
Quoting 1287. Neapolitan:
Could you be bothered to provide links to the place(s) any "expert" said GW would lead to an above-average season? If you can't, we'll all have to just assume that statement is yet another meaningless straw man to be ignored, and nobody wants that. Thanks!


GW/climate change, I cant keep the two straight..

Skeptical Science: there were about 60 entries alone from this website posted from the GW camp yesterday on WU..where are all those strong hurricanes that were supposed to happen this year? Landfalls? yep...

Recent research has shown that we are experiencing more storms with higher wind speeds, and these storms will be more destructive, last longer and make landfall more frequently than in the past. Because this phenomenon is strongly associated with sea surface temperatures, it is reasonable to suggest a strong probability that the increase in storm intensity and climate change are linked.
Member Since: August 19, 2006 Posts: 13 Comments: 18134
1290. Patrap
Quoting 1288. GTstormChaserCaleb:
Amazing with all that dry air and it's raining here in Daytona Beach.



Most is at the mid levels, so squeaking out that Rain is not uncommon, happened here last weekend .
Member Since: Posts: Comments:
Quoting 1286. Patrap:
Q: How about hurricanes?
A: The new report gives %u201Clow confidence%u201D--a 20% chance--that we have observed a human-caused increase in intense hurricanes in some parts of the world. This is a reduction from the 2007 report, which said that it was more likely than not (greater than 50% chance.) The IPCC likely took note of a landmark 2010 review paper, "Tropical Cyclones and Climate Change", authored by ten top hurricane scientists, which concluded that the U.S. has not seen any long-term increase in landfalling tropical storms and hurricanes, and that "it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes." The 2013 IPCC report predicts that there is a greater than 50% chance (more likely than not) that we will see a human-caused increase in intense hurricanes by 2100 in some regions; this is a reduction from the 2007 report, which said this would be likely (66% chance or higher.)


What is phunny, is the rant is covered in Masters summary above.

LOL


I do think many questions would be answered on here about GW and hurricanes if people would read Dr. Masters' posts beyond the headline. I think it's possible, due to increased temperatures in the polar regions, that this shift will remain so. There's simply no focus of heat in our basins with plentiful amounts of heat in the northern latitudes. Hurricanes act as A/C units, bringing heat to the poles from the tropics. Seeing as there's already enough heat in the northern latitudes, I'd argue hurricanes and typhoons are becoming unnecessary. But we'll see if an active period returns to the Atlantic again, because I think the one that started in 1995 ended in 2010.
Member Since: July 8, 2005 Posts: 259 Comments: 25950
Quoting 1282. Patrap:
Phunny all the IPCC bashers are posting in a PHD's entry on it.

Irony at is best I'd say.

Fresca?

Ahhhhhhhhhhhh




Amazing with all that dry air and it's raining here in Daytona Beach.

Member Since: June 30, 2013 Posts: 12 Comments: 10603
Quoting 1277. TampaSpin:
GW caused this Lull you know....just like GW had the experts saying an above average season. I never once thought this would be an above average season and actually posted in late July why it would be below average. ONWARD and waiting for the waters to rise over Florida. :) Everyone have a great day!
Could you be bothered to provide links to the place(s) any "expert" said GW would lead to an above-average season? If you can't, we'll all have to just assume that statement is yet another meaningless straw man to be ignored, and nobody wants that. Thanks!
Member Since: November 8, 2009 Posts: 4 Comments: 15191
1286. Patrap
Q: How about hurricanes?
A: The new report gives “low confidence”--a 20% chance--that we have observed a human-caused increase in intense hurricanes in some parts of the world. This is a reduction from the 2007 report, which said that it was more likely than not (greater than 50% chance.) The IPCC likely took note of a landmark 2010 review paper, "Tropical Cyclones and Climate Change", authored by ten top hurricane scientists, which concluded that the U.S. has not seen any long-term increase in landfalling tropical storms and hurricanes, and that "it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes." The 2013 IPCC report predicts that there is a greater than 50% chance (more likely than not) that we will see a human-caused increase in intense hurricanes by 2100 in some regions; this is a reduction from the 2007 report, which said this would be likely (66% chance or higher.)


What is phunny, is the rant is covered in Masters summary above.

LOL
Member Since: Posts: Comments:
Quoting 1271. washingtonian115:
I'm going to get my new car today :) (Range Rover sport).I've been saving up for it for a while now.The two summer storms and Sandy last year cut into those savings.But 2013 has been nicer to us (Thank goodness).Maybe go to Pentagon city afterwards.


Post a pic of it!
Member Since: August 4, 2007 Posts: 0 Comments: 3649
Quoting 1277. TampaSpin:



GW caused this Lull you know....just like GW had the experts saying an above average season. I never once thought this would be an above average season and actually posted in late July why it would be below average. ONWARD and waiting for the waters to rise over Florida. :) Everyone have a great day!


TS, c'mon, you know full well why we thought it looked like it would be an above average season. You've been on here for many years to know that a season with above average SSTs, lower than average shear, and no El Nino usually spells trouble for the Atlantic. The only problem I saw was below-average vertical instability, which is indeed the main problem, or one of them. It wasn't global warming that prompted the figures.

It's not just this basin that's suffering, it's the entire planet's hurricane seasons that have been suffering. ACE for 2013 across the entire planet is below average, and in general has been for several years. There's simply no focus of heat in the basins, causing hurricanes to be unnecessary.

Let's look at how the -PDO has been behaving, for the last few seasons, it has generally been negative with maybe a few times in the positive region.

2006** 1.03 0.66 0.05 0.40 0.48 1.04 0.35 -0.65 -0.94 -0.05 -0.22 0.14
2007** 0.01 0.04 -0.36 0.16 -0.10 0.09 0.78 0.50 -0.36 -1.45 -1.08 -0.58
2008** -1.00 -0.77 -0.71 -1.52 -1.37 -1.34 -1.67 -1.70 -1.55 -1.76 -1.25 -0.87
2009** -1.40 -1.55 -1.59 -1.65 -0.88 -0.31 -0.53
0.09 0.52 0.27 -0.40 0.08
2010** 0.83 0.82 0.44 0.78 0.62 -0.22 -1.05 -1.27 -1.61 -1.06 -0.82 -1.21
2011** -0.92 -0.83 -0.69 -0.42 -0.37 -0.69 -1.86 -1.74 -1.79 -1.34 -2.33 -1.79
2012** -1.38 -0.85 -1.05 -0.27 -1.26 -0.87 -1.52 -1.93 -2.21 -0.79 -0.59 -0.48
2013** -0.13 -0.43 -0.63 -0.16
0.08 -0.78 -1.25 -1.04

The last time we saw this was in the 70s, when it was generally inactive across the Atlantic and the world. So it doesn't have be related to global warming, but I do think the PDO is partly to blame and it'll be interesting to see if it shifts or not.

1971 -1.90 -1.74 -1.68 -1.59 -1.55 -1.55 -2.20 -0.15 0.21 -0.22 -1.25 -1.87
1972 -1.99 -1.83 -2.09 -1.65 -1.57 -1.87 -0.83 0.25 0.17 0.11 0.57 -0.33
1973 -0.46 -0.61 -0.50 -0.69 -0.76 -0.97 -0.57 -1.14 -0.51 -0.87 -1.81 -0.76
1974 -1.22 -1.65 -0.90 -0.52 -0.28 -0.31 -0.08 0.27 0.44 -0.10 0.43 -0.12
1975 -0.84 -0.71 -0.51 -1.30 -1.02 -1.16 -0.40 -1.07 -1.23 -1.29 -2.08 -1.61

The Earth needs a full-out, 1997 style El Nino to get its hurricane and typhoon going again in the Pacific, because it simply ain't happening with this negative -PDO. Either way, it doesn't look good for an active 2014 Atlantic hurricane season either.

It's safe to say that 2013 will end up being a massive forecasting bust, but it wasn't CSU or TSR pulled it our of their hats to make it seem GW is a thing or not. They've usually been dead on the last few years.
Member Since: July 8, 2005 Posts: 259 Comments: 25950
1283. hydrus
The latest addition to the endangered species list, The Atlantic hurricane..lol

Member Since: September 27, 2007 Posts: 1 Comments: 28034
1282. Patrap
Phunny all the IPCC bashers are posting in a PHD's entry on it.

Irony at is best I'd say.

Fresca?

Ahhhhhhhhhhhh




Member Since: Posts: Comments:
IF ONLY CLIMATE CHANGE COULD BRING US SOMETHING POSITIVE!!! (RAIN)



Member Since: October 6, 2007 Posts: 0 Comments: 8751
Water vapor loop sure looks like the ncgom is closed for a while, probably the season.
Member Since: Posts: Comments:
1279. hydrus
Quoting 1273. SLU:


All of these aforementioned years also had major hurricanes before October which we will not see this year. That says that the conditions in these years were better than 2013. A great deal will have to change in the coming weeks to even get a 1/2 decent looking hurricane in October, let alone a major one.

Good morning Slu. It is only me harmless opinion, but I believe we will still get a major hurricane this year. Atmospheric conditions have been submarginal and a small window of better conditions should arise in the Central and Western Caribbean during the secondary peak. You have been here a long time, if a crow falls on my plate, I will still think of the fodder that taught me another lesson on the dynamic and sometimes unpredictable tropics..:)
Member Since: September 27, 2007 Posts: 1 Comments: 28034

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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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