Hurricanes and Climate Change: Huge Dangers, Huge Unknowns

By: Dr. Jeff Masters , 9:57 AM GMT on August 05, 2013

Share this Blog
74
+

Hurricane Sandy's enormous $65 billion price tag put that great storm in third place for the most expensive weather-related disaster in U.S. (and world) history, and six of the ten most expensive U.S. weather-related disasters since 1980 have been hurricanes. Thus, how the strongest hurricanes may be affected due a changing climate is a topic of critical concern. Since hurricanes are heat engines that extract heat energy from the oceans to power themselves, hurricane scientists are confident that the very strongest storms will get stronger by the end of the century, when Earth's land and ocean temperatures are expected to warm 2 - 3°C, to levels unmatched since the Eemian Era, 115,000 years ago. Computer modeling work consistently indicates that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100. But hurricanes are fussy creations, and are sensitive to wind shear and dry air. Although the strongest storms should get stronger when "perfect storm" conditions are present, these "perfect storm" conditions may become less frequent in the future, due to the presence of higher wind shear, altered atmospheric circulation patterns, or more dry air at mid levels of the atmosphere. Indeed, the climate models used to formulate the 2007 IPCC report suggested that we might see the strongest hurricanes getting stronger, but a decrease in the total number of hurricanes in the Atlantic (and worldwide) later this century. However, the latest set of models used to formulate the 2013 IPCC report left open the possibility that we might see in increase in the total number of hurricanes, and and increase in their intensity. Given the conflicting model results, we really don't know how global warming will affect the number of hurricanes and their intensity, but we run the risk of making one of humanity's greatest scourges worse.


Figure 1. The list of most expensive U.S. weather-related disasters since 1980 is dominated by hurricanes.

Climate models and hurricane frequency
The database we have on historical hurricanes does not extend far enough into the past and is not of high enough quality to make many judgements on how human-caused climate change may be affecting these great storms. A landmark 2010 review paper, "Tropical Cyclones and Climate Change", authored by ten top hurricane scientists 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" (tropical cyclone is the generic term which encompasses tropical depressions, tropical storms, hurricanes, and typhoons.) Based in part on modeling studies using climate models run for the 2007 IPCC report, the scientists concluded that "it is likely that global mean tropical cyclone frequency will either decrease or remain unchanged owing to greenhouse warming." For example, one of the modeling studies the review paper quoted, Knutson et al. (2008), "Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions", projected a decrease in Atlantic tropical storms by 27% and hurricanes by 18% by the end of the century. An important reason that their model predicted these decreases was due to a predicted increase in wind shear. As I explain in my wind shear tutorial, a large change of wind speed with height over a hurricane creates a shearing force that tends to tear the storm apart. The amount of wind shear is critical in determining whether a hurricane can form or survive.

But a July 2013 study by MIT's Dr. Kerry Emanuel, "Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century", challenged this result. Dr. Emanuel argued that tropical cyclones are likely to become both stronger and more frequent as the climate continues to warm. This increase is most likely to occur in Western North Pacific, with smaller increases in the Atlantic. Dr. Emanuel took output from six newer higher-resolution climate models used to formulate the 2013 IPCC report, and used the output to drive a high-resolution hurricane model. The simulations found that the global frequency of tropical cyclones would increase by 11% to 40% by 2100, with intensity increases as well. The combined effects produced a global increase in Category 3 and stronger hurricanes of 40%. The behavior of these strongest hurricanes is critical, since they do most of the damage we observe. Over the past century, Category 3 - 5 hurricanes accounted for 85% of US hurricane damage, despite representing only 24% of U.S. landfalling storms. Category 4 and 5 hurricanes made up only 6% of all U.S. landfalls, but accounted for 48% of all U.S. damage (if normalized to account for increases in U.S. population and wealth, see Pielke et al., 2008.)


Figure 2. Projected changes in tropical cyclone track density during the 2006-2100 period compared to the 1950-2005 period, using output from six climate models included in the 2013 IPCC report. The global frequency of tropical cyclones is predicted to increase by 11% to 40%, with the largest changes occurring in the Northwest Pacific off the coast of Japan. Smaller increases are predicted for the Atlantic and near Australia. Image credit: Kerry Emanuel, "Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century", Proceedings of the National Academy of Sciences, July 8, 2013, doi: 10.1073/pnas.1301293110.

However, a study by Knutson et al. (2013), using the same latest-generation climate models as used by Emanuel (2013), but using the output from the models to drive a different high-resolution hurricane model, found a 20% decrease in Atlantic tropical storms and hurricanes by 2100. Two other 2013 studies by Villarini et al. and Camargo, also using output from the 2013 IPCC models, found essentially no change in Atlantic tropical cyclones. The reason for the differences, lies, in part, with how much global warming is assumed in the studies. Dr. Emanuel's study, which found an increase in tropical cyclone activity, assumed a worst-case warming situation (RCP 8.5), following the "business as usual" emissions path humanity is currently on. The Knutson et al. study, which found a decrease of 20% in Atlantic tropical cyclones, used a scenario (RCP 4.5) where it was assumed humans will wise up and cause about half of the worst-case greenhouse warming. The study found found "marginally significant" increases in Atlantic Category 4 and 5 hurricanes of 39% - 45% by 2100. These dramatically different results give credence to Dr. Emanuel statement at the end of his paper, "the response of tropical cyclones to projected climate change will remain uncertain for some time to come." The 2013 IPCC report also emphasized the high amount of uncertainty in how climate change might affect hurricanes, stating that there was "low confidence" that we have observed any increases in intense tropical cyclones due to human causes. However, since the 1970s, it is virtually certain (99 - 100% chance) that the frequency and intensity of hurricanes and tropical storms in the North Atlantic has increased, and there is medium confidence that a reduction in small air pollution particles (aerosols) over the North Atlantic caused part of this effect. The report's forecast for the future stated that it is "more likely than not" (50 - 100% chance) that human-caused climate change will cause a substantial increase in intense tropical cyclones in some ocean basins by 2100, with the Western North Pacific and Atlantic being at particular risk. Also, there will likely (66 - 100% chance) be an increase in both global mean tropical cyclone maximum wind speed and rain rates by 2100, and more likely than not (50 - 100% chance) that the increase in the most intense tropical cyclones will be larger than 10% in some basins.


Figure 3. Expected change in Atlantic Category 4 and 5 hurricanes per decade expected by the year 2100, according to Knutson et al. (2013), "Dynamical Downscaling Projections of 21st Century Atlantic Hurricane Activity: CMIP3 and CMIP5 Model-based Scenarios." This research used the latest generation of climate models from the 2013 IPCC report, and found "marginally significant" increases in Atlantic Category 4 and 5 hurricanes of 39% - 45% by 2100.

Commentary
Hurricane damages are currently doubling every ten years without the effect of climate change, according to Pielke et al., 2008. This is primarily due to the increasing population along the coast and increased wealth of the population. The authors theorize that the Great Miami Hurricane of 1926, a Category 4 monster that made a direct hit on Miami Beach, would have caused about $150 billion in damage had it hit in 2005. Thus, by 2015, the same hurricane would do $300 billion in damage, and $600 billion by 2025. This is without considering the impact that accelerating sea level rise will have on storm surge damages. Global sea level rise over the past decade has been about double what it was in the 20th century, and the rate of sea level rise is expected to increase further in the coming decades. Storm surge does the majority of damage in major hurricanes, and storm surges riding on top of higher sea levels are going to do a lot more damage in the coming decades. If we toss in the (controversial) increases in Category 3 and stronger storms like Dr. Emanuel suggests may occur, the hurricane damage math gets very impressive. We can also add onto that the relatively non-controversial increase in tropical cyclone rainfall of 20% expected by 2100, which will sharply increase damages due to fresh water river flooding. It is controversial whether or not we are already be seeing an increase in heavy precipitation events associated with tropical cyclones in the U.S., though. The total number of daily rainfall events exceeding 2" associated with tropical cyclones in the Southeast U.S. on a century time scale has not changed significantly, according to Groisman et al., 2004. But a 2010 study by Kunkel et al., "Recent increases in U.S. heavy precipitation associated with tropical cyclones", found that the number of Southeast U.S. tropical cyclone heavy precipitation events, defined as 1-in-5-year events, more than doubled between 1994 - 2008, compared to the long-term average from 1895 - 2008.


Figure 4. Time series of the 15-year running average (plotted at the end point of the 15-yr blocks) of a Tropical Cyclone Heavy Precipitation Index (red) and 15-year running average of U.S. landfalling hurricanes (blue). Note that there has been no long-term increase in U.S. landfalling hurricanes, but there has been a sharp increase in extreme rainfall events associated with landfalling tropical cyclones--the kind of rainfall events most likely to cause damaging flooding. Image credit: Kunkel et al. (2010), "Recent increases in U.S. heavy precipitation associated with tropical cyclones", Geophysical Research Letters.

It is essential that we limit coastal development in vulnerable coastal areas, particularly along barrier islands, to reduce some of the astronomical price tags hurricanes are going to be causing in the future. Adoption and enforcement of strict building standards is also a must, as well as more reforms to the government's National Flood Insurance Program (NFIP), which subsidizes development in high-risk coastal regions that private insurers won't touch. NFIP is now $25 - 30 billion in the red, thanks to Hurricane Katrina and Hurricane Sandy. Reform of NFIP is already underway. In 2012, before Sandy hit, Congress passed the Biggert-Waters Flood Insurance Reform Act, which requires people with NFIP policies to pay large premium increases of about 25% per year over the next five years. Naturally, this move has caused major controversy.

References
Camargo, S., (2013), "Global and regional aspects of tropical cyclone activity in the CMIP5 models," J. Climate.

Emanuel, K.A., 2013, "Downscaling CMIP5 climate models shows increased tropical cyclone activity over the 21st century", PNAS, July 8, 2013, doi: 10.1073/pnas.1301293110

Groisman, Pavel Ya, et al., "Contemporary changes of the hydrological cycle over the contiguous United States: Trends derived from in situ observations," Journal of Hydrometeorology 5.1 (2004): 64-85.

Knutson et al., 2010, "Tropical Cyclones and Climate Change", Nature Geoscience 3, 157 - 163, Published online: 21 February 2010 | doi:10.1038/ngeo779

Knutson et al., 2013, Dynamical Downscaling Projections of 21st Century Atlantic Hurricane Activity: CMIP3 and CMIP5 Model-based Scenarios, Journal of Climate 2013 ; e-View
doi: http://dx.doi.org/10.1175/JCLI-D-12-00539.1

Pielke, R.A, et al., 2008, "Normalized Hurricane Damage in the United States: 1900 - 2005," Natural Hazards Review, DOI:10.1061/ASCE1527-6988(2008)9:1(29)

Villarini, G, and G.A. Vecchi, 2012, "Twenty-first-century projections of North Atlantic tropical storms from CMIP5 models," Nature Clim. Change 2:604–607.

Related posts
Global warming and the frequency of intense Atlantic hurricanes: model results, my 2010 blog post.

Climate Central's analysis of the new 2013 Kerry Emanuel paper.

Goodbye, Miami: Jeff Goodell's sobering 2013 article in Rolling Stone on the challenges Miami faces due to sea level rise and hurricanes.


What the official climate assessments say about climate change and hurricanes
The 2013 IPCC 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 in odds 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. had 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 also a reduction from the 2007 report, which said this would be likely (66% chance or higher.)

The May 2014 United States National Climate Assessment found that “The intensity, frequency, and duration of North Atlantic hurricanes, as well as the frequency of the strongest (Category 4 and 5) hurricanes, have all increased since the early 1980s. The relative contributions of human and natural causes to these increases are still uncertain. Hurricane-associated storm intensity and rainfall rates are projected to increase as the climate continues to warm.”

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 2019 - 1969

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52Blog Index

Quoting 2013. Grothar:
so nhc said anything on it gro?
Member Since: Posts: Comments:
2018. JLPR2
Quoting 2015. ILwthrfan:


I definately see rotation on radar. Look east south east of Barbados.



If shear weren't so high in the Caribbean it would have a decent chance at developing further down the road.


Member Since: Posts: Comments:
2017. Grothar
Quoting 2012. bigwes6844:
can it form though gro? it really looks good


There is very high wind shear in the eastern Caribbean. Very rare any storms form there. There is also a big ULL to the Northeast of it. So I think unlikely at this time.

Member Since: Posts: Comments:
2016. Patrap
TEPCO struggling to contain contaminated water

Member Since: July 3, 2005 Posts: 424 Comments: 128284
Quoting 1974. GetReal:


While this t-wave approaching Barbados looks good on latest satellite pics, radar indicates that there is not any evidence of a cyclonic rotation forming... Link


I definately see rotation on radar. Look east south east of Barbados.

Member Since: Posts: Comments:
Yo Gro!

We are under a dreaded Coastal Flood Advisory for tides of 1 to 1 1/2 feet above normal.

It doesn't take much to flood us. The Chesapeake Bay area is subsiding and has added about 1 additional foot to sea level rise in the past century.

Member Since: Posts: Comments:
2013. Grothar
Member Since: Posts: Comments:
Quoting 2008. Grothar:


It's a blob I've been watching and posting for about 4 days. I didn't think it would get this round, but I had written a few days ago, that I expected some bad weather through the middle islands by Wednesday.
can it form though gro? it really looks good
Member Since: Posts: Comments:
2011. Grothar
Quoting 2007. redwagon:


LOL earlier the MD office of NHC somehow was involved with composing a TWO and they said well there's this over there and then there's that over here and Miami jumped back with NO THERE AIN'T.

Said we should all just go to the bar for the next 48 hours.


Well I don't drink, but I'll have a club soda with a twist and wait for the NHC to say something. I don't expect much development yet.
Member Since: Posts: Comments:
2010. JLPR2
Quoting 2003. stormchaser19:
GFS 18z..FANTASY


That's something, I'm with the group that thinks late August is when the season will get active and that would be right on schedule. 3rd-last week of August.
Member Since: Posts: Comments:
Quoting 2001. CaicosRetiredSailor:
Warp speed troll wipe is nice!
like a cat 5 bout to hit the U. S. and a trough takes it out the sea! nice!
Member Since: Posts: Comments:
2008. Grothar
Quoting 2002. bigwes6844:
that looks pretty darn good! wats da deal with it?


It's a blob I've been watching and posting for about 4 days. I didn't think it would get this round, but I had written a few days ago, that I expected some bad weather through the middle islands by Wednesday.
Member Since: Posts: Comments:
Quoting 2000. Grothar:


LOL earlier the MD office of NHC somehow was involved with composing a TWO and they said well there's this over there and then there's that over here and Miami jumped back with NO THERE AIN'T.

Said we should all just go to the bar for the next 48 hours.
Member Since: Posts: Comments:
Quoting 2003. stormchaser19:
GFS 18z..FANTASY


Really no point in that because the GFS shows stuff like that all the time, and never pans out.
Member Since: July 31, 2013 Posts: 0 Comments: 925
Quoting 1994. Tazmanian:



Or may be its you why not you go and do some in fun then hanging around on the blogs. There is other things in life then this blog
I'm not sure if to laugh at this comment or take it serious.Never mind I'm laughing..Lol.I've been doing other things with my life over the past week and I've been very busy.Why don't you stop policing the blog and get your own life in order first before telling others what to do?.
Member Since: Posts: Comments:
2004. auburn (Mod)
Quoting 2001. CaicosRetiredSailor:
Warp speed troll wipe is nice!


And we thank you all for not quoting them!
Member Since: Posts: Comments:
GFS 18z..FANTASY
Member Since: Posts: Comments:
Quoting 2000. Grothar:
that looks pretty darn good! wats da deal with it?
Member Since: Posts: Comments:
Warp speed troll wipe is nice!
Member Since: Posts: Comments:
2000. Grothar
Member Since: Posts: Comments:
Quoting 1995. BaltimoreBrian:


They were asleep.

I read about this story elsewhere and read that the snake actually fell through the ceiling. If that is what happened, and if it fell on the unfortunate boys, then the snake might well have reacted as if it was attacked. That's my guess at this point.

However it happened, it is heart-breaking.
Member Since: Posts: Comments:
Quoting 1932. sar2401:

Do you have a link to this story? It seems almost impossible that two boys, assuming that at least one of them was able to run, could have been killed by one python. There must be more to this stroy.


They were asleep.
Member Since: Posts: Comments:
Quoting 1984. washingtonian115:
LMAO.Some people won't give up..



Or may be its you why not you go and do some in fun then hanging around on the blogs. There is other things in life then this blog
Member Since: Posts: Comments:
1993. zampaz
Quoting 1892. goosegirl1:


As usual, I am late to the party :). I majored in biology, not physics, so someone correct me if I am wrong, but Newton's Law of Universal Gravitation is an equation that allows us to predict what will happen when a given object is dropped, but does not tell us why this happens. Einstein's General Theory of Relativity gives us a working model for why gravity works the way it does, and as in all theories, it is subject to update as new data is found.

So we can predict what will happen, but no one is certain why. We all know that gravity works, we can prove there is a force called gravity... but it's a theory.

Well said! In science everything is subject to change as knowledge and understanding improve. People often confuse the words "Theory" with "Hypothesis" and there is a natural desire for a sense of security in unchanging "laws", but interpretation of knowledge based in fact isn't like that.
If you're not a scientist and you hear a scientist use the word "theory", you can bet your boots the theory is not just an educated guess based on observations(hypothesis). A theory has been experimentally verified repeatedly usually through multiple disciplines. Theories not only explain, they allow prediction.

The universe operates on principles, and we use language and mathematics to abstractly describe and predict what we observe.

Member Since: Posts: Comments:
Quoting 1895. TropicalAnalystwx13:
InAccuweather is insane.

Accuweather: You cannot be serious (new 45-day forecasts)



Sweet, t-storm in the morning and a nice sunny day with a high of 83 for my birthday.

Now I have to wait 3 weeks to see if they're right. -_-
Member Since: Posts: Comments:


Member Since: Posts: Comments:
huge wave!
Member Since: Posts: Comments:
1986. Patrap
Utah Methane Leaks In Gas Fields Higher Than Originally Thought, Challenging U.S. Estimates
Posted: 08/06/2013 6:13 pm EDT


From Climate Central's Andrew Freedman:

A new study of the air above a natural gas field in Utah suggests that far more methane gas may be escaping into the atmosphere from drilling operations than previously estimated. The study, to be published in the journal Geophysical Research Letters, is the first to use an aircraft to directly sample the air downwind of natural gas and oil wells in order to calculate emissions of methane and contributors to smog. Most other studies to date have relied on various estimating techniques to determine methane emissions associated with natural gas drilling.

The new study sheds insight on a critical question just how much methane gas, which in the short-term is a far more powerful global warming agent than carbon dioxide (CO2) is escaping from drilling, processing, shipping, and burning natural gas in the U.S.? The Environmental Protection Agency (EPA) estimates that, nationally, the methane leakage rate is about 1.5 percent, but other recent studies have suggested that is a lowball estimate.

This new study, while limited in scope to one natural gas field on one particular day in 2012, also argues for a higher estimate of methane leakage, on the order of between 6.2 and 11.7 percent.

Colm Sweeney, a coauthor of the study and a scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder, told Climate Central that he was surprised by the huge amount of methane emissions the study found. We're estimating that 9 percent of that is just leaking right out, never getting to the end of the pipeline . . . to the actual user point, he said.

With the U.S. increasingly relying on natural gas to generate electricity, displacing dirtier coal, a critical question facing scientists and government regulators is exactly how beneficial the switch will be for curbing man-made global warming. Over the long-term, natural gas is a cleaner-burning fuel than coal is because it emits far less CO2, the main long-term global warming gas. And already, burning more natural gas has helped dramatically lower U.S. carbon emissions from the power sector.

Yet over the short-term, natural gas production also releases methane gas, which is 25 times more powerful in warming the climate than CO2 is over a 100-year time horizon, according to the study.

more,...
Member Since: July 3, 2005 Posts: 424 Comments: 128284
LMAO.Some people won't give up..
Member Since: Posts: Comments:
Quoting 1963. Grothar:




There you are.. be on standby for pre-blob issuance advisory update debriefing announcement.

And remember, you saw it first. Taz is off rafting somewhere.
Member Since: Posts: Comments:
Quoting 1975. GTstormChaserCaleb:
GFS 123 hrs.



Yeah thats what its on, but its usually over by this time.
Member Since: July 31, 2013 Posts: 0 Comments: 925
1976. nigel20
Quoting 1953. NasBahMan:


Happy Independence Day Nigel, we like to say we all live in Paradise on our islands in the sea but there is still lots of work we can do in the coming years to make each of our island nations better places for all who live in them.

Agreed. Thanks for your very kind words, NBM!
Member Since: November 6, 2010 Posts: 11 Comments: 8029
Quoting 1960. SuperStorm093:
man the GFS runs so slow now.
GFS 123 hrs.

Member Since: June 30, 2013 Posts: 12 Comments: 8273
1974. GetReal


While this t-wave approaching Barbados looks good on latest satellite pics, radar indicates that there is not any evidence of a cyclonic rotation forming... Link
Member Since: Posts: Comments:
Quoting 1936. SLU:


Yes redwagon. This wave could be a player in a couple days if it holds together.


Kinda popped up out of nowhere, huh? This is exciting. Maybe Skye will post some A/Oscats when she gets in.
Member Since: Posts: Comments:
1972. Patrap
2012 Climate Change Report From NOAA Reveals Rising Seas, Snow Melt And More Warming


By SETH BORENSTEIN 08/06/13 04:28 PM ET AP

WASHINGTON -- A new massive federal study says the world in 2012 sweltered with continued signs of climate change. Rising sea levels, snow melt, heat buildup in the oceans, and melting Arctic sea ice and Greenland ice sheets, all broke or nearly broke records, but temperatures only sneaked into the top 10.

The National Oceanic and Atmospheric Administration on Tuesday issued a peer-reviewed 260-page report, which agency chief Kathryn Sullivan calls its annual "checking on the pulse of the planet." The report, written by 384 scientists around the world, compiles data already released, but it puts them in context of what's been happening to Earth over decades.

"It's critically important to compile a big picture," National Climatic Data Center director Tom Karl says. "The signs that we see are of a warming world."

Sullivan says what is noticeable "are remarkable changes in key climate indicators," mentioning dramatic spikes in ocean heat content, a record melt of Arctic sea ice in the summer, and whopping temporary melts of ice in most of Greenland last year. The data also shows a record-high sea level.

The most noticeable and startling changes seen were in the Arctic, says report co-editor Deke Arndt, climate monitoring chief at the data center. Breaking records in the Arctic is so common that it is becoming the new normal, says study co-author Jackie Richter-Menge of the U. S. Army Corps of Engineers' Cold Regions Research and Engineering Laboratory in Hanover, N.H.

Karl says when looked at together, all the indicators show a climate that is changing over the decades. Individually, however, the story isn't as simple.

Karl says surface temperatures haven't risen in the last 10 years, but he notes that is only a blip in time due to natural variability. When looking at more scientifically meaningful time frames of 30 years, 50 years and more than 100 years, temperatures are rising quite a bit, Karl said. Since records have been kept in 1880, all 10 of the warmest years ever have been in the past 15 years, NOAA records show.

Depending on which of four independent analyses are used, 2012 ranked the eighth or ninth warmest year on record, the report says. Last year was warmer than every year in the previous century, except for 1998 when a record El Nino spiked temperatures globally. NOAA ranks 2010 as the warmest year on record.

They don't have to be records every year, Karl says.

Overall the climate indicators "are all singing the same song that we live in a warming world," Arndt says. "Some indicators take a few years off from their increase. The system is telling us in more than one place we're seeing rapid change."

While the report purposely doesn't address why the world is warming, "the causes are primarily greenhouse gases, the burning of fossil fuels," Arndt says.

The study is being published in a special edition of the Bulletin of the American Meteorological Society.

___

Online:

The Climate of 2012 report: http://www.ncdc.noaa.gov/bams-state-of-the-climate /2012.php
Member Since: July 3, 2005 Posts: 424 Comments: 128284
nvm...fixed
Member Since: Posts: Comments:
1970. KEEPEROFTHEGATE (Mod)
Quoting 1967. clwstmchasr:


Didn't Dr. Masters say in a previous blog that the SAL outbreak was normal for late July/early August?


normal for it to be coming to an end
and the current was quite the dust storm large and dense
and happen at the normal end of big outbreaks
get dust all the time
but not as intense as we just saw
Member Since: July 15, 2006 Posts: 171 Comments: 53838
Overshooting tops along the northern eyewall covering the eye...same thing happened with Gil last week when it was trying to clear out its eye.

Member Since: Posts: Comments:

Viewing: 2019 - 1969

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

Local Weather

Mostly Cloudy
76 °F
Mostly Cloudy