The Biggest Control Knob: CO2 in Earth's Climate History
It's been a busy past two months of weather and climate change news, and I haven't found time to blog about the research presented at December's American Geophysical (AGU) meeting in San Francisco. That is the world's largest scientific conference on climate change, and the place to be if you want to get the pulse of the planet. The keynote speech at the AGU meeting was given by Dr. Richard Alley of Penn State University. Dr. Alley is the Evan Pugh Professor of Geosciences at the Pennsylvania State University, and one of the most respected and widely published world experts on climate change. Dr. Alley has testified before Congress on climate change issues, served as lead author of "Chapter 4: Observations: Changes in Snow, Ice and Frozen Ground" for the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), and is author of more than 170 peer-reviewed scientific articles on Earth's climate. He is also the author of a book I highly recommend--The Two Mile Time Machine, a superb account of Earth's climate history as deduced from the 2-mile long Greenland ice cores. A standing-room only audience of over 2,000 scientists packed the lecture hall Dr. Alley spoke at, and it was easy to see why--Alley is an excellent and engaging speaker. I highly recommend listening to his 45-minute talk via a very watchable recording showing his slides as he speaks in one corner of the video. If you want to understand why scientists are so certain of the link between CO2 and Earth's climate, this is a must-see lecture.
Figure 1. Dr. Richard Alley of Penn State University, delivering the keynote speech at the 2009 AGU conference on climate change.
The Biggest Control Knob: CO2 in Earth's Climate History
Earth's past climate has been shaped by a number of key "control knobs"--solar energy, greenhouse gas levels, and dust from volcanic eruptions, to name the three main ones. The main thrust of Dr. Alley's speech is that we have solid evidence now--some of it very new--that CO2 has dominated Earth's climate over the past 400 million years, making it the climate's "biggest control knob". Dr. Alley opens his talk by humorously discussing a letter from an irate Penn State alumnus. The alumnus complains that data of temperatures and CO2 levels from ice cores in Antarctica don't match:
"CO2 lags Earth's temperature...This one scientific fact which proves that CO2 is not the cause of recent warming, yet...Dr. Alley continues to mislead the scientific community and the general public about 'global warming'. His crimes against the scientific community, PSU, the citizens of this great country, and the citizens of the world are significant and must be dealt with severely to stop such shameful activities in the future".
Dr. Alley explains that the irate alumnus is talking about the Antarctic ice core record, which shows that as we emerged from each ice age, the temperature began increasing before the CO2 did, so increased CO2 was not responsible for the warmings that brought us out of these ice ages. Climate change scientists and skeptics alike agree that Earth's ice ages are caused by periodic variations in Earth's orbit called Milankovich Cycles. "There's no doubt that the ice ages are paced by the orbits", says Dr. Alley. "No way that the orbit knows to dial up CO2, and say 'change'. So it shouldn't be terribly surprising if the CO2 lags the temperature change. The temperature never goes very far without the CO2. The CO2 adds to the warming. How do we know that the CO2 adds to the warming? It's physics!"
Dr. Alley then discusses that the physics that govern how CO2 absorbs and re-emits heat energy, when plugged into state-of-the-art climate models, show that about half of the observed 5 - 6°C natural warming that occurred since the last ice age ended was due to extra CO2 added to the atmosphere. At the peak of the Ice Age, CO2 was about 190 ppm. By the end, it was about 280 ppm (Figure 1). Earth's orbital variations "forced" a warming, which caused more CO2 to escape from swamps and oceans, with a time lag of several centuries. The increased CO2 reinforced the warming, to double what it would have been otherwise--a positive feedback loop. "Higher CO2 may be forcing or feedback--a CO2 molecule is radiatively active regardless of how it got there", says Dr. Alley. "A CO2 molecule does not remember why it is there--it only remembers that it is there". In other words, the fact that higher CO2 levels did not trigger an end to the Ice Age does not mean that the CO2 had no warming effect. Half of the the observed 5 - 6°C natural warming that occurred since the last ice age ended was due to the extra CO2 added to the atmosphere. So, the irate PSU alumnus was half right. The CO2 does lag temperature. However, we can only explain approximately half of the warming since the last ice age ended if we leave out the increase in CO2 that has occurred. "If higher CO2 warms, Earth's climate history makes sense, with CO2 having caused or amplified the main changes. If CO2 doesn't warm, we have to explain why the physicists are so stupid, and we also have no way to explain how a lot of really inexplicable climate events happened over Earth's history. It's really that simple. We don't have any plausible alternative to that at this point".
Figure 2. Ice core record from Vostok, Antarctica, showing the near-simultaneous rise and fall of Antarctic temperature and CO2 levels through the last 350,00 years, spanning three ice age cycles. However, there is a lag of several centuries between the time the temperature increases and when the CO2 starts to increase. Image credit: Marian Koshland Science Museum of the National Academy of Sciences: Global Warming Facts and Our Futures, originally provided to that site by Kurt Cuffey, University of California, Berkely.
CO2 and temperatures rise and fall in synch
Dr. Alley continues with a discussion of how CO2 and temperature levels have risen and fallen in synch over most of geologic time. But for many years there was still a mystery: occasionally there were eras when temperature changes did not match CO2 changes. But new paleoclimate research, much of it just in the past two years, has shown that nearly all of these mis-matches were probably due to suspect data. For example, the mismatch in the Miocene Era has significantly improved, thanks to a new study published this year by Tripati et al. Another example occurs during the Ordovician Era 444 million years ago, as discussed in a recent post at the excellent skepticalscience.com blog.
Figure 3. Atmospheric CO2 and continental glaciation, 400 million years ago to the present. The vertical blue bars mark where ice ages have occurred. The length of the blue bars corresponds to how close to the Equator the ice sheets got (palaeolatitude, scale on the right side of the plot). The left scale shows atmospheric CO2 over the past 400 million years, as inferred from a model (green area) and from four different "proxy" fossil sources of CO2 information. This is Figure 6.1 of the Palaeoclimate chapter of the 2007 IPCC report.
Is there anything else we should be worried about?
Dr. Alley continues with a discussion of other influences that may be able to explain global warming, such as volcanos, changes in solar output, and cosmic rays. A whole bunch of the competing hypotheses don't work", says Dr. Alley. "When there's a bunch of big volcanos, they make it cool. If volcanos could get organized, they'd rule the world. There might be a tiny bit of organization due to flexing of the crust, but they're not controlling the world".
Regarding solar changes: "When the sun changes, it does seem to show up in the temperature record. As far back as we can see well, the sun is friendly, it doesn't change much. If the sun changed a lot, it would control things hugely. But it only changes really slowly--as far as we can tell. The record doesn't go back as far as we'd like, and there's work to be done here--but it just doesn't seem to be doing much".
Figure 4. Greenland ice core proxy measurements of temperature (top curve) and cosmic ray flux (bottom curve) for the past 60,000 years. The Earth's magnetic field weakened by 90% 40,000 years ago, for a period of about 1,000 years, but there was no change seen in the temperatures in Greenland.
Regarding cosmic rays: "The sun doesn't change much, but the sun modulates the cosmic rays, the cosmic rays modulate the clouds, the clouds modulate the temperature, and so the sun is amplified hugely. It's really interesting hypothesis, there's really good science to be done on this, but there's reason to think its a fine-tuning knob". He goes on to show an ice core example from a period 40,000 years ago (Figure 4) where the Earth magnetic field had near-zero strength for hundreds of years. This allowed a massive flux of cosmic rays to penetrate to the Earth's surface, creating a huge spike in ice core Beryllium-10, a radionuclide made by cosmic rays. If cosmic rays were important to climate, we would expect to see a corresponding major swing in temperature, but the ice core shows no change during the period of enhanced cosmic ray bombardment 40,000 years ago. "We had a big cosmic ray signal, and the climate ignores it", Dr. Alley comments.
How sensitive is climate to a doubling of CO2?
The IPCC report talks extensively about computer climate models' calculations of "climate sensitivity"--how much Earth's climate would warm if CO2 doubled from pre-industrial levels of 280 ppm, to 560 ppm (we're currently at 390 ppm). A mid-range number from the 2007 IPCC report often used by climatologists is that the climate sensitivity is 3°C for a doubling of CO2. Dr. Alley takes a look at what paleoclimate has to say about the climate sensitivity to CO2. "The models actually do pretty well when you compare them to the past. The best fit is 2.8°C.
Dr. Alley concludes, "Where we really stand now, is, we're not quite at the pound on the table, this story is very clearly not done. But an increasing body of science indicates that CO2 has been the most important controller of global average climate of the Earth."
I'll have a new post Sunday or Monday.
Jeff Masters
Reader Comments
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No need. It either validates or it doesn't.
Again, the minutia behind the predictions is irrelevant, other than for better understanding.
If it doesn't validate, it is wrong. It's not rocket science.
Knock yourself out with that.
If you predict 2C-4C and I predict <1C by 2100, all that matters is what the temperature is at 2100.
Only need another 10 years of data, but at that point I'll bet anyone a $10K donation to the charity of their choosing that +2C in 2100 from 2000 will not happen.
Ummm... it's in Doc's post. Or is he not talking about global climate?
Obscure? How so? It's just data.
As I said in a previous post. Everyone can interpret it as they see it.
As mentioned, I am not versed on that topic.
I will check it out, though.
For what it's worth, I think there are some issues with a lack of aerosol measurements. Research papers have been published that suggest the long period of tropical cyclone inactivity in the Atlantic last century was due to air pollution in Europe being brought south to the tropical Atlantic and reflecting sunlight and that air pollution controls in Europe have reduced these aerosols thus now more cyclones. Most of the people on the blog, though, stick with, to me, a mythical multidecadal cycle of hurricane activity in the Atlantic. Such a cycle is unprovable at present. There is no causal mechanism given for it--just like the PDO--and we don't have accurate data for enough years. It is just an anomaly given a name.
Yeah, aerosols are important.
looks like i came in at a bad time
night
You really should watch the video. It won't hurt. Trust me.
"Yeah, aerosols are important." You betcha.
Good night all.
Since I don't know which of the doc's posts you are talking about, I don't have a clue.
I guess it just doesn't make any sense to me then. If I knew what you were trying to show, I might be able to comment.
I believe we are barking up the wrong tree.
I have no confidence that this is worrisome. (Orange line is 1979 - 2000 "normal" extend for this date).
We have been ignoring a lot of other things to battle out the politics of AGW.
Things like:
wastewater/sewage treatment
the pacific garbage patch (seen the new Sun Chips compostable bags? I wonder if they magically disappear in the oceans...make ALL bags that way if they do)
VOC emissions from industry, esp. olefins - surface ozone
superfund sites
soot/particulates from diesel-powered autos
help/convince Asian countries to clean up sooty emissions
efficiency standards for personal vehicles
*NEW* GM just announced a cheaper, more effective (cause more can be used) mineral for catalytic converters...less NOx to come at a cheaper cost
nitrogen fertilizer use - algal blooms
many, many more
We have real problems that have a clear cause, effect, and solution. But we are burning all political favor on a blink-worth of data, that we have coined "normal", and models that contain a lot of assumptions and big holes in the physics of how long-term climate works...because we do not have a lot of physical understanding of how it works, mostly theories.
Awww, bull. I haven't really been participating in this discussion for the last few months, either.
I have to agree with my fellow aggie on this...
You do realize they are mostly just condensated water due to the temperature difference between exhaust and ambient air in the presence of water vapor, right?
After 9/11/2001, the detectible difference in the US was a 2 C high diurnal range (high temp - low temp)...BUT it was also a very clear day (or 3), also. Attribution has it's caveats. Net effect on temperature? Very debatable that there is one.
Haven't seen much else noteworthy.
Read the blog entry... Vostok.
Bedtime.
Thankfully my son's ballgame isn't 9am tomorrow as it has been for the last month.
You home?
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - NORTHERN REGION
Issued by DARWIN TROPICAL CYCLONE WARNING CENTRE
at: 0750 UTC 27/03/2010
Name: Tropical Low
Identifier: 11U
Data At: 0600 UTC
Latitude: 11.2S
Longitude: 136.4E
Location Accuracy: within 60 nm [110 km]
Movement Towards: southeast [130 deg]
Speed of Movement: 8 knots [14 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1001 hPa
Radius of 34-knot winds NE quadrant:
Radius of 34-knot winds SE quadrant:
Radius of 34-knot winds SW quadrant:
Radius of 34-knot winds NW quadrant:
Radius of 48-knot winds NE quadrant:
Radius of 48-knot winds SE quadrant:
Radius of 48-knot winds SW quadrant:
Radius of 48-knot winds NW quadrant:
Radius of 64-knot winds:
Radius of Maximum Winds:
Dvorak Intensity Code: T2.0/2.0/D1.0/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar:
Storm Depth: Medium
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 27/1800: 11.7S 136.6E: 090 [165]: 030 [055]: 997
+24: 28/0600: 12.1S 136.6E: 120 [220]: 040 [075]: 994
+36: 28/1800: 12.5S 136.4E: 150 [280]: 035 [065]: 997
+48: 29/0600: 12.5S 136.0E: 185 [345]: 025 [045]: 1002
+60: 29/1800: 12.6S 135.7E: 230 [430]: 025 [045]: 1002
+72: 30/0600: 12.7S 135.8E: 280 [520]: 030 [055]: 1000
REMARKS:
The tropical low has significantly improved its structure during the past 6 hours with cold tops expanding near the systyem centre. Spiral bands with 0.45 wrap have developed in the eastern sectors and a well-defined LLCC is evident on radar west of the Wessel Islands. Dvorak DT=2.5, MET and PAT=2.0. FT=2.0 due to 6-hour change constraints. Rapid intensification forecast for next 12 hours due to recently improved structure and favourable low-shear environment with good outflow channels to the south and north.
Consensus of model forecasts continues recent slow S or SSE movement closer to the coast into a break in the mid-level ridge. After 24 hours, the system is expected to become near stationary just inland over Arnhemland and weaken slightly below TC intensity. After 48 hours, a mid-level trough amplifying over eastern Australia is expected to combine with strengthening low-level NW flow to steer the system over the Gulf of Carpentaria where it may reintensify.
Copyright Commonwealth of Australia
==
The next bulletin for this system will be issued by: 27/1330 UTC by Darwin Tropical Cyclone Warning Centre.
Link
No I don't believe it's condensated water. Condensated water wasn't known to expand and create cloud cover all of my life until the late 90's when I began noticing the oddities. I do believe they are aerosols and I do believe they serve someone's purpose.
Lights go out worldwide for Earth Hour
* From: AAP
* March 27, 2010 11:17PM
SYDNEY Opera House fell into darkness tonight as millions of lights were switched off across Australia, kicking off a global energy-saving marathon.
Homes and businesses killed their lights at 8.30pm (AEDT) for Earth Hour in an effort to lower the planet's carbon footprint and raise awareness of the environment.
In Sydney, harbour ferry horns blared to signal the rolling event, which began in New Zealand and will wrap up 25 hours later in Apia, Samoa, at 6.30pm (AEDT) on Sunday.
Earth Hour executive director Andy Ridley said: "I'm so amazed that people take part on the scale that they do and enjoy it, because that's what it's about.
"What we're still looking for in this coming year is a global deal that encourages all countries to lower their emissions and China is going to have to be a big part of that but so is every other major economy."
In December, two weeks of UN talks in Copenhagen failed to produce a binding commitment to limit global warming or set out concrete plans for doing so, in a setback for the environmental movement.
But commitment to change still exists at a grassroot level.
Earth Hour is supported by 4000 cities in a record 125 countries. It also includes 1200 landmarks, among them the Pyramids, the Tower of Pisa and the Eiffel Tower.
For the first time, the Forbidden city in Beijing is also be taking part, along with 20 cities across China, despite the country's resistance at Copenhagen.
Earth Hour began in Sydney in 2007 when 2.2 million people switched off the lights in their homes, offices and businesses for 60 minutes to make a point about electricity consumption and carbon pollution.
The campaign went global the following year, and it has now harnessed support from a raft of multinational companies including Google, Coca-Cola, Hilton, McDonalds, Canon, HSBC and IKEA.
TROPICAL CYCLONE ADVICE NUMBER 6
Issued by the BUREAU OF METEOROLOGY, DARWIN
at 8:11 pm CST Saturday 27 March 2010
A Cyclone WARNING is current for coastal and island communities from Maningrida
to Cape Shield, including Nhulunbuy, and now extends to Numbulwar, including
Groote Eylandt.
A Cyclone WATCH continues for coastal and island communities from Goulburn
Island to Maningrida and now extends from Numbulwar to Port Roper.
The Cyclone WATCH from Cape Don to Goulburn Island has been cancelled.
At 6:30 pm CST a Tropical Low was estimated to be 65 kilometres north of
Nhulunbuy and 140 kilometres east northeast of Elcho Island and moving south
southeast at 13 kilometres per hour.
The low is expected to develop into a tropical cyclone in the next 12 to 18
hours.
GALES with gusts to 110 kilometres per hour are expected to develop between
MANINGRIDA and NUMBULWAR, including NHULUNBUY and GROOTE EYLANDT, ealry tomorrow
morning.
Tides will be HIGHER THAN NORMAL between ELCHO ISLAND and GROOTE EYLANDT tonight
and during Sunday. Large waves may produce MINOR FLOODING of low-lying coastal
areas.
HEAVY RAIN may lead to localised flooding and significant stream rises in the
Arnhem District tonight and during Sunday.
Details of Tropical Low at 6:30 pm CST:
.Centre located near...... 11.6 degrees South 136.8 degrees East
.Location accuracy........ within 110 kilometres
.Recent movement.......... towards the south southeast at 13 kilometres per hour
.Wind gusts near centre... 85 kilometres per hour
.Severity category........ below cyclone intensity
.Central pressure......... 1000 hectoPascals
The next advice will be issued by 11:00 pm CST Saturday 27 March.
Rosebud Lambert, Saturday March 27, 2010 -
A developing tropical low is gaining strength in the Arafura Sea as it edges slowly towards the Top End.
The tropical low is expected to cross the northeastern tip of the Top End late on Sunday with the possibility that it may develop into a tropical cyclone just before landfall. Communities from Cape Don to Nhulunbuy are on Cyclone Watch.
Beyond this land crossing models are predicting the tropical low may move east into the Gulf of Carpentaria. A weak return of the monsoon trough and strong winds aloft may assist in the low intensifying, possibly to cyclonic strength.
Whatever the intensity of the tropical low it is set to bring heavy rainfall and storms. Some areas in the eastern Top End have already received over 80mm of rain in 24 hours. The rain will continue with amounts possibly exceeding 300mm over the next three days.
- Weatherzone
Yup, I know.
But, it's still just a "FEEL GOOD", backwards approach.
Take it for what it's worth.
;>)
Issued by the BUREAU OF METEOROLOGY, DARWIN
at 11:12 pm CST Saturday 27 March 2010
A Cyclone WARNING continues for coastal and island communities from Milingimbi
to Numbulwar, including Nhulunbuy and Groote Eylandt.
The Cyclone WARNING from Maningrida to Milingimbi has been cancelled.
A Cyclone WATCH continues for coastal and island communities from Maningrida to
Milingimbi and from Numbulwar to Port Roper.
A Cyclone WATCH has been extended from Port Roper to Port McArthur.
The Cyclone WATCH from Goulburn Island to Maningrida has been cancelled.
At 9:30 pm CST a Tropical Low was estimated to be 15 kilometres southeast of
Nhulunbuy and 185 kilometres north northeast of Alyangula and moving south
southeast at 22 kilometres per hour.
The low is expected to develop into a tropical cyclone in the next 12 to 18
hours.
DESTRUCTIVE WINDS with gusts to 130 kilometres per hour may develop between
ALYANGULA and NUMBULWAR late on Sunday or early Monday.
GALES with gusts to 110 kilometres per hour are expected to develop between
NHULUNBUY AND NUMBULWAR, including GROOTE EYLANDT, early tomorrow morning. Gales
may extend west to MILINGIMBI if the system takes a more westerly track.
Tides will be HIGHER THAN NORMAL between ELCHO ISLAND and NUMBULWAR, including
GROOTE EYLANDT, tonight and during Sunday. Large waves may produce MINOR
FLOODING of low-lying coastal areas.
HEAVY RAIN may lead to localised flooding and significant stream rises in the
Arnhem District tonight and during Sunday.
Details of Tropical Low at 9:30 pm CST:
.Centre located near...... 12.3 degrees South 136.9 degrees East
.Location accuracy........ within 110 kilometres
.Recent movement.......... towards the south southeast at 22 kilometres per hour
.Wind gusts near centre... 85 kilometres per hour
.Severity category........ below cyclone intensity
.Central pressure......... 1001 hectoPascals
The next advice will be issued by 2:00 am CST Sunday 28 March.
Good lord. It gets pretty dumb around here at times.
That would be in the presence of a fairly moist ambient air mass. Dissipates quicker in a dry atmosphere.
You really ascribe to the conspiracy theory that is the chemtrail thing?
In a search on google, I found nothing but conspiracy theories and the wiki page. I hate source wiki, but not even google scholar had any science on the matter.
Wiki:
"According to a United States Air Force contrail fact sheet, contrails, or condensation trails, are "streaks of condensed water vapor created in the air by an airplane or rocket at high altitudes."[7] These condensation trails are the result of normal emissions of water vapor from piston engines and jet engines at high altitudes in which the water vapor condenses into a visible cloud. Contrails are formed when hot humid air from the engines mix with, and are cooled by, the colder surrounding air. (The mixing is a result of turbulence generated by the jet engine exhaust). Colder air has less capacity to hold moisture. The rate at which contrails dissipate is entirely dependent upon weather conditions and altitude. If the atmosphere is near saturation, the contrail may exist for some time. Conversely, if the atmosphere is dry, the contrail will dissipate quickly.
Chemtrails, coming from "chemical trails" in the same fashion that contrail comes from "condensation trail" is a term coined to suggest that contrails are formed by something other than a natural process of engine exhaust hitting the cold air in the atmosphere. Chemtrail conspiricists characterize these chemical trails as streams that persist for hours, and by their criss-crossing, grid-like patterns, or parallel stripes which eventually blend to form large clouds. Proponents view the presence of visible color spectra in the streams, unusual concentrations of sky tracks in a single area, or lingering tracks left by unmarked or military airplanes flying in atypical altitudes or locations as markers of chemtrails."
You have an science source, I'll look at it. But I have to tell you that I have an atmospheric chemistry background and nothing, I mean nothing, in any course I took, data I have seen, or reports I have read have ever suggested that contrails were anything other than condensated water and the usual exhaust gases and particles (not visible).
Are you really talking chemtrails or contrails? There is apparently a difference.
And no net temperature change was recorded that could be attributed after 9/11, just the diurnal range increase coincident with clear weather (muddying whether or not there is any effect)
You know of any published articles that say otherwise?
Greetings earthling!
Nice radar image of the tropical low
QUIKSCAT HAS NOT BEEN REPLACED AND HURRICANE SEASON IS COMING.
I think priorities need to be rethought......
That was interesting thanks. Never knew what he looked like before. :) He's saying a lot of what I've been reading on here. Not crazy about his analog years here in Texas. 98 had 2 tropical storms. 07 had a tropical storm and Humberto, We just had the one in 2005. Although Emily gave south Texas quite a ride spawning tornadoes. There's just no good way to go with any of those years for anybody. Blah!
Close up
128km
256km
ASCAT and other scatterometers on orbit,though not as wide a swath as Quikscat,will be adequate for covering the Systems.
Were not flying blind without Quikscat.
Morning WUBAland.
Science takes a back seat to ,fodder ,..again
What is it?
greenhouse gases in the Earth's atmosphere
Graphics from Intergovernmental Panel on Climate Change Report Summary
Global warming -- a gradual increase in planet-wide temperatures -- is now well documented and accepted by scientists as fact. A panel convened by the U.S National Research Council, the nation's premier science policy body, in June 2006 voiced a "high level of confidence" that Earth is the hottest it has been in at least 400 years, and possibly even the last 2,000 years. Studies indicate that the average global surface temperature has increased by approximately 0.5-1.0°F (0.3-0.6°C) over the last century. This is the largest increase in surface temperature in the last 1,000 years and scientists are predicting an even greater increase over this century. This warming is largely attributed to the increase of greenhouse gases (primarily carbon dioxide and methane) in the Earth's upper atmosphere caused by human burning of fossil fuels, industrial, farming, and deforestation activities.
Average global temperatures may increase by 1.4-5.8ºC (that's 2.5 - 10.4º F) by the end of the 21st century. Although the numbers sound small, they can trigger significant changes in climate. (The difference between global temperatures during an Ice Age and an ice-free period is only about 5ºC.) Besides resulting in more hot days, many scientists believe an increase in temperatures may lead to changes in precipitation and weather patterns. Warmer ocean water may result in more intense and frequent tropical storms and hurricanes. Sea levels are also expected to increase by 0.09 - 0.88 m. in the next century, mainly from melting glaciers and expanding seawater . Global warming may also affect wildlife and species that cannot survive in warmer environments may become extinct. Finally, human health is also at stake, as global warming may result in the spreading of certain diseases such as malaria, the flooding of major cities, a greater risk of heat stroke for individuals, and poor air quality.
Climate change is very likely having an impact now on our planet and its life, according to the latest installment of a report published by the Intergovernmental Panel on Climate Change (IPCC). And the future problems caused by rising seas, growing deserts, and more frequent droughts all look set to affect the developing world more than rich countries, they add. The report is the second chapter of the IPCC's Fourth Assessment -- the most comprehensive summary yet of research into the causes and effects of climate change. To read more, visit Effects of climate change tallied up.
Factors
Greenhouse Gases
The increase in greenhouse gases caused by human activity is often cited as one of the major causes of global warming. These greenhouse gases reabsorb heat reflected from the Earth's surface, thus trapping the heat in our atmosphere. This natural process is essential for life on Earth because it plays an important role in regulating the Earth's temperature. However, over the last several hundred years, humans have been artificially increasing the concentration of these gases, mainly carbon dioxide and methane in the Earth's atmosphere. These gases build up and prevent additional thermal radiation from leaving the Earth, thereby trapping excess heat.
Solar Variability & Global Warming
temperature, CO2, and sunspotsSome uncertainty remains about the role of natural variations in causing climate change. Solar variability certainly plays a minor role, but it looks like only a quarter of the recent variations can be attributed to the Sun. At most. During the initial discovery period of global warming, the magnitude of the influence of increased activity on the Sun was not well determined.
Solar irradiance changes have been measured reliably by satellites for only 30 years. These precise observations show changes of a few tenths of a percent that depend on the level of activity in the 11-year solar cycle. Changes over longer periods must be inferred from other sources. Estimates of earlier variations are important for calibrating the climate models. While a component of recent global warming may have been caused by the increased solar activity of the last solar cycle, that component was very small compared to the effects of additional greenhouse gases. According to a NASA Goddard Institute for Space Studies (GISS) press release, "...the solar increases do not have the ability to cause large global temperature increases...greenhouse gases are indeed playing the dominant role..." The effects of global warming are apparent (see section below) despite the fact that the Sun is once again less bright during the present solar minimum. Since the last solar minimum of 1996, the Sun's brightness has decreased by 0.02% at visible wavelengths, and 6% at extreme UV wavelengths, representing a 12-year low in solar irradiance, according to this NASA news article (April 1, 2009). Also, be sure to read this more recent article: 2009: Second Warmest Year on Record; End of Warmest Decade.
How about doing both, participate in "Earth Hour" and plan trips to the store, the less you nip out to the store to grab something you "need" the less pollution you will create. I participate in "Earth Hour", I did it the easy way, I fell asleep before nightfall and woke to a darkened house.
Even China is participating in "Earth Hour" this year. I wonder how many people there will participate in "Earth Hour"????
Introduction, PALEOCLIMATE RECONSTRUCTION
No method for directly measuring ancient climate exists; climate is not fossilized in rocks or sediments. Fortunately many kinds of climatic indicators are preserved for us to interpret. Various physical or biological processes are dependent on such aspects of climate as temperature, moisture, and seasonality. All attempts to reconstruct Quaternary climate are subject to some uncertainty and must be accompanied by age dating in order to be of any use. Some of the most valuable methods are stable isotopes, palynology and paleofauna.
World Data Center for Paleoclimatology.
Oxygen-isotope ratios
Oxygen occurs in two common, stable isotopes, 16O and 18O, of which 16O is the most abundant. The ratio of these two isotopes in water is temperature dependent and follows predictable geographic trends in the oceans, atmosphere, and glaciers--see Fig. 11-1. The ratio is altered whenever water undergoes a phase change. When sea water evaporates, for example, the heavier isotope 18O is preferentially left behind in remaining sea water, while the resulting water vapor is depleted in 18O. The oxygen-isotope composition of a water sample is expressed in delta (d) units per mil (1%u2030 = 0.1%) of relative concentrations with respect to the ratio of standard mean ocean water (SMOW).
18O/16O sample - SMOW
d = --------------------- x 1000
SMOW
By definition, d is zero for standard mean ocean water. A value of d = -10 thus means the sample has an 18O/16O ratio 10% (or 1%) less than SMOW. The amount of water or ice required for analysis is small (5-10 g), and stable isotopes can be measured quite accurately using mass spectrographic techniques.
Under present conditions, the volume of land ice is relatively small, and this ice has d values around -30. During glacial periods, however, much isotopically light water was removed from oceans and stored in glaciers on land. This caused slight enrichment of 18O in sea water to about d = 1.5, while glacier ice had even lower d values of around -40--see Fig. 11-2. The oxygen-isotope values during past glaciations are preserved in glacier ice and in fossils buried on the sea floor. These isotopic records are primarily a measure of changing volume of glacier ice.
Oxygen-isotope ratios are also affected by temperature, for example, the water temperature in which corals grow or the air temperature in which snow crystallizes. The temperature effect is beautifully illustrated by annual oxygen-isotope layering in the Greenland Ice Sheet--see Fig. 11-3.
Atmospheric CO2 record from Vostok ice core and other sources. The record matches closely with paleoclimatic indicators. Recent CO2 levels are higher than any previous values in the ice-core record. World Data Center-A for Paleoclimatology, Educational Slide Project.
Vostok ice core record of atmospheric CO2, temperature change, and methane (CH4). This record shows a strong correlation between greenhouse gases and temperature during the last 160,000 years. However, it is not clear what mechanisms are responsible for this relationship. World Data Center-A for Paleoclimatology, Educational Slide Project.
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We support research into our world's frozen realms: the snow, ice, glacier, frozen ground, and climate interactions that make up Earth's cryosphere. Scientific data, whether taken in the field or relayed from satellites orbiting Earth, form the foundation for the scientific research that informs the world about our planet and our climate systems.
Darn. Too good to be true.
(Really, though, if it would break down in the ocean, it would break down in Louisiana air, too ;-)
(Yeah, Florida's air, too)
Speaking of that, have you all noticed how many products just aren't meant for humid environs?
From that smell in most any Miami hotel room to the red mark inside a cell phone (they say you got your phone wet, to which I usually say "I walked outside with it 3 times"), a lot of things simply seem to work great in Phoenix, but not along the gulf coast.
2010 Data News
25 March 2010
NSIDC is pleased to announce the release of a new data set, Co-Registered AMSR-E, QuikSCAT, and WMO Data. The data set contains the following spatially and temporally co-registered data:
* Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) brightness temperatures for all channels
* Quick Scatterometer (QuikSCAT) backscattering coefficients
* World Meteorological Organization (WMO) ground observations acquired from more than two thousand stations
QuikSCAT and WMO data are available from 01 January 2002 through 19 March 2009, and AMSR-E data are included from 19 June 2002 through 19 March 2009. For more information and data access, please refer to the Co-Registered AMSR-E, QuikSCAT, and WMO Data product Web page.
He shows graphs of C02 vs Temp from Vostok to prove that point, graphs from Greenland in another.. Now if GLOBAL warming is due to C02 please show me data from many sites over the same time frame from around the GLOBE..but that Never seems to happen...
Even better is the fact the graph does not show dust which seems to follow the same cycle from another graph at wiki
http://en.wikipedia.org/wiki/Ice_age
makes you wonder if some time shifts occurred in data and the temperature going down caused the C02 to go up due to less photosynthesis occurring
Or maybe our 1979 - 2000 "normal" was anomalously icy and what were are seeing today *is* normal.
Oh and, the southern hemisphere just had their warmest winter on record, but look at the ice lol. Hmm.
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