Hansen: "Humans have overwhelmed the natural, slow changes that occur on geologic timescales"

From NASA Goddard/GISS: same-o, same-o

Paleoclimate Record Points Toward Potential Rapid Climate Changes

temperature map of earth

The average global surface temperature of Earth has risen by .8 degrees Celsius since 1880, and is now increasing at a rate of about .1 degree Celsius per decade. This image shows how 2010 temperatures compare to average temperatures from a baseline period of 1951-1980, as analyzed by scientists at NASA’s Goddard Institute for Space Studies. Credit: NASA GISS

New research into the Earth’s paleoclimate history by NASA’s Goddard Institute for Space Studies director James E. Hansen suggests the potential for rapid climate changes this century, including multiple meters of sea level rise, if global warming is not abated.

By looking at how the Earth’s climate responded to past natural changes, Hansen sought insight into a fundamental question raised by ongoing human-caused climate change: “What is the dangerous level of global warming?” Some international leaders have suggested a goal of limiting warming to 2 degrees Celsius from pre-industrial times in order to avert catastrophic change. But Hansen said at a press briefing at a meeting of the American Geophysical Union in San Francisco on Tues, Dec. 6, that warming of 2 degrees Celsius would lead to drastic changes, such as significant ice sheet loss in Greenland and Antarctica.

Based on Hansen’s temperature analysis work at the Goddard Institute for Space Studies, the Earth’s average global surface temperature has already risen .8 degrees Celsius since 1880, and is now warming at a rate of more than .1 degree Celsius every decade. This warming is largely driven by increased greenhouse gases in the atmosphere, particularly carbon dioxide, emitted by the burning of fossil fuels at power plants, in cars and in industry. At the current rate of fossil fuel burning, the concentration of carbon dioxide in the atmosphere will have doubled from pre-industrial times by the middle of this century. A doubling of carbon dioxide would cause an eventual warming of several degrees, Hansen said.

In recent research, Hansen and co-author Makiko Sato, also of Goddard Institute for Space Studies, compared the climate of today, the Holocene, with previous similar “interglacial” epochs – periods when polar ice caps existed but the world was not dominated by glaciers. In studying cores drilled from both ice sheets and deep ocean sediments, Hansen found that global mean temperatures during the Eemian period, which began about 130,000 years ago and lasted about 15,000 years, were less than 1 degree Celsius warmer than today. If temperatures were to rise 2 degrees Celsius over pre-industrial times, global mean temperature would far exceed that of the Eemian, when sea level was four to six meters higher than today, Hansen said.

“The paleoclimate record reveals a more sensitive climate than thought, even as of a few years ago. Limiting human-caused warming to 2 degrees is not sufficient,” Hansen said. “It would be a prescription for disaster.”

Hansen focused much of his new work on how the polar regions and in particular the ice sheets of Antarctica and Greenland will react to a warming world.

Two degrees Celsius of warming would make Earth much warmer than during the Eemian, and would move Earth closer to Pliocene-like conditions, when sea level was in the range of 25 meters higher than today, Hansen said. In using Earth’s climate history to learn more about the level of sensitivity that governs our planet’s response to warming today, Hansen said the paleoclimate record suggests that every degree Celsius of global temperature rise will ultimately equate to 20 meters of sea level rise. However, that sea level increase due to ice sheet loss would be expected to occur over centuries, and large uncertainties remain in predicting how that ice loss would unfold.

Hansen notes that ice sheet disintegration will not be a linear process. This non-linear deterioration has already been seen in vulnerable places such as Pine Island Glacier in West Antarctica, where the rate of ice mass loss has continued accelerating over the past decade. Data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellite is already consistent with a rate of ice sheet mass loss in Greenland and West Antarctica that doubles every ten years. The GRACE record is too short to confirm this with great certainty; however, the trend in the past few years does not rule it out, Hansen said. This continued rate of ice loss could cause multiple meters of sea level rise by 2100, Hansen said.

Ice and ocean sediment cores from the polar regions indicate that temperatures at the poles during previous epochs – when sea level was tens of meters higher – is not too far removed from the temperatures Earth could reach this century on a “business as usual” trajectory.

“We don’t have a substantial cushion between today’s climate and dangerous warming,” Hansen said. “Earth is poised to experience strong amplifying feedbacks in response to moderate additional global warming.”

Detailed considerations of a new warming target and how to get there are beyond the scope of this research, Hansen said. But this research is consistent with Hansen’s earlier findings that carbon dioxide in the atmosphere would need to be rolled back from about 390 parts per million in the atmosphere today to 350 parts per million in order to stabilize the climate in the long term. While leaders continue to discuss a framework for reducing emissions, global carbon dioxide emissions have remained stable or increased in recent years.

Hansen and others noted that while the paleoclimate evidence paints a clear picture of what Earth’s earlier climate looked like, but that using it to predict precisely how the climate might change on much smaller timescales in response to human-induced rather than natural climate change remains difficult. But, Hansen noted, the Earth system is already showing signs of responding, even in the cases of “slow feedbacks” such as ice sheet changes.

The human-caused release of increased carbon dioxide into the atmosphere also presents climate scientists with something they’ve never seen in the 65 million year record of carbon dioxide levels – a drastic rate of increase that makes it difficult to predict how rapidly the Earth will respond. In periods when carbon dioxide has increased due to natural causes, the rate of increase averaged about .0001 parts per million per year – in other words, one hundred parts per million every million years. Fossil fuel burning is now causing carbon dioxide concentrations to increase at two parts per million per year.

“Humans have overwhelmed the natural, slow changes that occur on geologic timescales,” Hansen said.

Patrick Lynch

NASA’s Earth Science News Team

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Willis Eschenbach

My favorite line was:

Based on Hansen’s temperature analysis work at the Goddard Institute for Space Studies, the Earth’s average global surface temperature has already risen .8 degrees Celsius since 1880, and is now warming at a rate of more than .1 degree Celsius every decade.

These guys can’t even tell a believable lie. It hasn’t warmed a tenth of a degree in the last decade, that’s nonsense.
w.

crosspatch

Getting a bit shrill, aren’t they?

Billy Liar

This isn’t science; it’s speculation.
Even a madman can speculate.

There is the possibility here of a new bootstrap event. According to this post Real Science (http://www.real-science.com/understanding-man-global-warming) ‘In the year 2000, Hansen and his buddies decided to give underachieving global warming a boost – by adding 0.6 degrees on to the disappointing US data set.’ So perhaps the above claim of a rise of 0.8C thanks to his work at the Goddard Institute for Space Studies is a bit of an exaggeration. In either case, the bootstrap event whereby an observer gets extremely distressed by the data he has just created is worthy of further study.

Claude Harvey

The man is utterly shameless..

Excuse me while I go and puke

Wherever paleo-climate studies have looked – on a regional basis – Antarctica, Greenland, Tibet – you find 2-3 degree Celsius changes with a beat-frequency of about 1000 years – some of these rises are very steep (Greenland) – within decades – and this is quite normal throughout ice-ages and interglacials. This probably translates to a global 0.5-1 degree shift.
The current warm period is expected on this frequency and not at all unusual in rate of change or amplitude – despite the presence of higher levels of CO2 and other greenhouse gases. Hansen has consistently misinterpreted the natural signal – as confirmation of his models and calculations of ‘sensitivity’ to carbon dioxide. If, as many of us calculate from the real world evidence of radiation flux measurements, CO2 can account for no more than 20-25% of the warming, then future temperatures will be determined by the natural cycle – and many paleo-climate experts think this will turn downward (see Liu’s work on Tibet featured in an earlier thread).
What is so annoying is the way that the left-liberal-green press only ever report Hansen’s opinions thus inflating the carbon currency bubble.

DirkH

“Humans have overwhelmed the natural, slow changes that occur on geologic timescales,” Hansen said.
But “natural variability” has overwhelmed the alleged AGW during the last 15 years, according to other CAGW proponents; I would suggest that the CAGW movement now splinters into warring factions.

richard verney

“Hansen and others noted that while the paleoclimate evidence paints a clear picture of what Earth’s earlier climate looked like…” Utter rubbish. We have no idea what the past climate was truly like. We are merely guessing.
We know as fact that the Vikings settled in Greenland and some of their settlements are just becoming apparent as glaciers recede. Those glaciers need to recede far more before the land will become farmable with primative equipment such that was possessed by the Vikings . May be Greenland needs to become several degrees (some speculate more than 4 degrees) hotter than today before it will be akin to the conditions that the VIkings enjoyed. What were the sea levels in the Northern Hemisphere at that time? That would be a good starting point since at least it would be grounded upon some basis of fact.

Shevva

‘Hansen said. In using Earth’s climate history to learn more about the level of sensitivity that governs our planet’s response to warming today, Hansen said the paleoclimate record suggests that every degree Celsius of global temperature rise will ultimately equate to 20 meters of sea level rise. However, that sea level increase due to ice sheet loss would be expected to occur over centuries, and large uncertainties remain in predicting how that ice loss would unfold.’
Says a lot doesn’t he. If you give me a million quid I’ll make you 20 but I cannot promise how it will unfold.

The last interglacial was 3-4degC warmer than present.
http://alsystems.algroup.co.uk/warming/CO2_temp.gif
This interglacial is steadily cooling.
http://www.climatedata.info/resources/Proxies/Ice-Cores/07-Temperature—Vostok-and-GISP2.gif
Oceans entered another 30-years long cooling period.
http://bobtisdale.files.wordpress.com/2011/12/5-no-hem.png
Per BEST own words, global records follows AMO/North Atlantic and the “human effect might be somehow overstated”. There is nothing unusual on period 1975-2005, it is equal to that of 1910-1940. AMO/NA SST are heading down again.
http://climexp.knmi.nl/data/ihadsst2_280-360E_0-70N_n.png
Fail on every level. Can I have some grants now?

janama

can some one over there take this man to dinner and fix his head?

Peter Miller

Complete unsubstantianted alarmist nonsense from a greedy crank, conflicted up to his ying yang – no alarmist stories, then no justification for his outrageous salary, therefore no job.
The CAGW faithful in Durban must love this alarmist stuff: “We don’t have a substantial cushion between today’s climate and dangerous warming,” Hansen said. “Earth is poised to experience strong amplifying feedbacks in response to moderate additional global warming.” So show us the proof in the geological record – the only problem is: it doesn’t exist!
Natural climate cycles are a complete heresy to the CAGW high priests – most of recent warming is due to them. Another heresy is to make the observation that global temperatures have been static/falling slightly over the past 10-12 years, likewise so is the fact that the rate of sea level rise has remained constant over the past two centuries.
The Eemian period was generally much warmer than Hansen states – unless, of course, he is right and everyone else is wrong – for instance this paper:
http://www.google.co.uk/url?sa=t&rct=j&q=eemian%20interglacial%20mean%20temperatures&source=web&cd=5&sqi=2&ved=0CEMQFjAE&url=http%3A%2F%2Fwww.mad.zmaw.de%2Ffileadmin%2Fextern%2FPublications%2Fmodel_data.pdf&ei=BuHhTqWdM4LN4QSPs9mKBQ&usg=AFQjCNG_Zv9J8AVLV1rryJcKWnr20WeAzQ&cad=rja

I think the Chinese tree ring record of Liu Y, Cai Q F, Song H M, et al., “Amplitudes, rates, periodicities and causes of temperature variations in the past 2485 years and future trends over the central-eastern Tibetan Plateau” (Chinese Sci Bull, 2011, 56: 29862994, doi: 10.1007/s11434-011-4713-7) deserves more attention. The nearly 2500 year record is far longer that Hansen’s, and shows a FLAT trend, The current ‘unprecedented’ warming was exceeded by 4 precedents from 400 to 1000.
In the first Fourier analysis I have seen of temperature data the power spectrum reveals eight(!) periodic influences at 99+% CL, with periods from 2.0 years to 1324 years. Four of these cycles are longer that Hansen’s entire ‘record.’

Curiousgeorge

Repackaged BS. Now sold as clean manure available at your local home and garden center.

H.R.

@Hansen
Chill out, dude. Everyone else will during the next glaciation. Beat the rush.

Eric Simpson

Two points: 1. temps are not unusual (no h. stick), and 2. CO2 is not a cause of warming: http://www.youtube.com/watch?v=WK_WyvfcJyg
Funny. I & others say that the trace gas CO2 is OVERWHELMED by stronger climate factors, that vary, such as the sun ocean etc etc. That $swindler & top bs artist Hansen has co-opted our language. There may be a theoretical basis for the trace gas CO2 having a warming effect, but there is NO EVIDENCE that it effects climate level temps… at all. If you have evidence, give it. I be waiting.

Peter Dunford

The map is completely misleading. The surface of the earth isn’ t a rectangle and that red band at the top is infilled from the hottest stations the can find 2,500 miles away. Made up data is exaggerated by the shape of the map.

pat

heavyweight hansen and others…
8 Dec: Oregon Live: OSU faculty, students prominent at one of the world’s leading scientific conferences
By Todd Simmons, Oregon State University
SAN FRANCISCO – Researchers from around the world gathered here this week … for the annual meeting of the American Geophysical Union, and Oregon State University faculty and graduate students were prominent in the conference’s vast program.
While the United Nations’ climate change conference was generating plenty of headlines … the more than 22,000 attendees at AGU were making news of their own on issues ranging from global warming to new policy governing key federal research.
NOAA Administrator Jane Lubchenco, a faculty member on leave from OSU, delivered a plenary lecture on the federal government’s management of extreme weather events. NOAA is tracking a record 12 such events, each with damages in excess of $1 billion, this year alone – droughts, floods, hurricanes, tornadoes, blizzards and wildfire…
Lubchenco also unveiled a new scientific integrity policy for NOAA – the first for the venerable science agency, which is perhaps a more notable development than it might seem: NOAA is America’s first science agency, with roots that reach back to the presidency of Thomas Jefferson. Among other things, the policy encourages transparency in research and frees researchers to discuss findings publicly on NOAA-funded research without prior approval.
The policy change earned immediate praise for Lubchenco and NOAA, with the Union of Concerned Scientists going so far as to pass out lapel stickers for AGU attendees reading, “You’re swell, Dr. L! Thanks for moving forward on scientific integrity.”…
But current OSU faculty were just as notable at the science summit, none more so than Associate Professor Andreas Schmittner, who over the past two weeks made headlines for a recently published study in Science magazine.
He and collaborators from Princeton, Cornell, Woods Hole and elsewhere developed new climate models that show the likelihood of global warming causing temperature increases of as much as 10 degrees Celsius are extremely unlikely. An increase in the 2.4-degree range would be more consistent with the new models, and Schmittner was quoted in news accounts as saying increases of 4.7 degrees or more would be “virtually impossible.”
Climate change heavyweight James Hansen of NASA and colleagues took issue with that at a Tuesday news conference at AGU, pointing to other models showing increases of 8.6 degrees or more…
http://blog.oregonlive.com/higher-education/2011/12/osu_faculty_students_prominent.html

Greg Holmes

Wow, I must be a lot more powerful than I think, I am now rated alongside a geological timescale, megga!
Why does my left knee still ache when its cold?

SteveW

“Two degrees Celsius of warming would make Earth much warmer than during the Eemian, and would move Earth closer to Pliocene-like conditions, when sea level was in the range of 25 meters higher than today”
Alternatively, 0.0000001 degrees of warming would move Eartgh closer to the temperature of the Sun, where any known form of life would be impossible.
Piece of piss this alarmism business, can I have a grant?

John Marshall

Let us have the evidence for these claims please Dr. Hansen. No evidence-claim a lie, simple as that.

SteveE

Hi Willis,
Could you yet me know what the Earth’s average global surface temperature anomaly was for the periods 2000 – 2010 and 1990 – 2000.
Just eyeballing this graph would suggest that it has warmed more than a tenth of a degree between those two time periods. I’ve probably got a different graph to you though.
http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.gif

Willis is, of course, correct. The GISS LOTI linear trend for the past 120 months is basically flat.
http://i39.tinypic.com/o8t8qg.jpg

This Hansen chap is probably preparing the base for an “Eemian Hockey stick” or some other kind of stick with a stunted blade

Gareth

My favourite line was:
“Two degrees Celsius of warming would make Earth much warmer than during the Eemian”.
That’s the same Eemian that saw Hippopotamus and Water Buffalo in Germany then?

markus

Here’s another lie.
“”Two degrees Celsius of warming would make Earth much warmer than during the Eemian, and would move Earth closer to Pliocene-like conditions, when sea level was in the range of 25 meters higher than today, Hansen said. In using Earth’s climate history to learn more about the level of sensitivity that governs our planet’s response to warming today, Hansen said the paleoclimate record suggests that every degree Celsius of global temperature rise will ultimately equate to 20 meters of sea level rise. However, that sea level increase due to ice sheet loss would be expected to occur over centuries, and large uncertainties remain in predicting how that ice loss would unfold.””Based on Hansen’s temperature analysis work at the Goddard Institute for Space Studies, the Earth’s average global surface temperature has already risen .8 degrees Celsius since 1880,””
If we have warmed .8 degress since 1880 how come the sea level out the back of my place hasn’t risen 16 meters since just before federation in Australia. Have a look a any seaside picture anywhere in the world from 1880 and then tell me how far the sea level has risen. CO2 Climate warmists need to get outside a bit more. And if anything, ice melt rate has slowed since LIA.

bushy

“Hansen found that global mean temperatures during the Eemian period, which began about 130,000 years ago and lasted about 15,000 years, were less than 1 degree Celsius warmer than today.”
They cannot even get the temperatures right with modern instruments today but they can guage the temp. back then within a degree?. Ha ha ha bshit.

ehak

Eschenbach:
You are right. It hasn’t warmed a tenth of a degree in the last decade. The mean of the latest 10 years is 0.17 degrees warmer than the last 10 years for hadcrut. Mean of NCDC and gistemp: 0.19 – 0.20 warmer.

Bloke down the pub

In studying cores drilled from both ice sheets and deep ocean sediments, Hansen found that global mean temperatures during the Eemian period, which began about 130,000 years ago and lasted about 15,000 years, were less than 1 degree Celsius warmer than today.
And there was me thinking that Hansen said current temperatures were unprecedented.

John West

“when sea level was tens of meters higher – is not too far removed from the temperatures Earth could reach this century on a “business as usual” trajectory.”
We all know how well his ’88 projection of BAU turned out. (Spot on according to Mann)
Dismal to anyone not invested in CAGW.
If 2C warming is now tragic then the next IPCC report must be going to estimate warming from 2XCO2 @ ~2C. Soon enough (IPCC report after next) they’ll have to proclaim that 1C warming is dangerous in order to keep up with the steadily falling sensitivity estimate.

charles nelson

Every time I hear of Hansen he reminds me more and more of Jim Jones…and his Monkey.

R.S.Brown

Jim Hansen… isn’t he the guy who worked with the muppets ?

markus

Here’s another lie;
“”global carbon dioxide emissions have remained stable or increased in recent years.””
With a third of the population bursting thru 10% growth, a ever expanding annual consumption from the coal bowls of the world, and the current T trend they slip one in about recent stability of CO2, when they know very well all the recent measurements of increasing Co2 and the T trend down.

Dr. Hansen,
Could you please provide actual, empirical, evidence that Man’s CO2 is the cause of your observed climate changes?
Thanks
JK

Bernie

I smell desperation. It is like saying the earth is going to be struck by a large meteor. It has happened before and there is no reason to believe it will not happen again. He is simply saying that when the ice caps melt we are in trouble. Yep, I agree. The question is when and through what mechanism.

Otter

1988: ‘That bridge will be under water in 20 years.’ (ten-foot rise required).
2011, 23 years later~ ‘I said 40 years, not 20! You (the reporter) got it wrong!’ (actual sea-level rise… unnoticeable).
Is hansen young enough that we can see what he claims in 2028?

OT: Climate Realists post an analysis of the truly nutso document being prepared at Durban. Its worse than we thought!
Ø A new International Climate Court will have the power to compel Western nations to pay ever-larger sums to third-world countries in the name of making reparation for supposed “climate debt”. The Court will have no power over third-world countries. Here and throughout the draft, the West is the sole target. “The process” is now irredeemably anti-Western.
Ø “Rights of Mother Earth”: The draft, which seems to have been written by feeble-minded green activists and environmental extremists, talks of “The recognition and defence of the rights of Mother Earth to ensure harmony between humanity and nature”. Also, “there will be no commodification [whatever that may be: it is not in the dictionary and does not deserve to be] of the functions of nature, therefore no carbon market will be developed with that purpose”.
Ø “Right to survive”: The draft childishly asserts that “The rights of some Parties to survive are threatened by the adverse impacts of climate change, including sea level rise.” At 2 inches per century, according to eight years’ data from the Envisat satellite? Oh, come off it! The Jason 2 satellite, the new kid on the block, shows that sea-level has actually dropped over the past three years.
Ø War and the maintenance of defence forces and equipment are to cease – just like that – because they contribute to climate change. There are other reasons why war ought to cease, but the draft does not mention them.
http://climaterealists.com/index.php?id=8807

DEEBEE

@Willis,
Not only that, even if you assume .* degree, it is in 130 years. My grade school math cannot make it a rate of more than .1 degree per decade, need Hansenian PhD

Aeronomer

There has been no statistically significant warming for the last decade. I can’t believe my taxes are paying this guy’s salary.

Peter Stroud

I have a horrid feeling that Hansen et al. got the answer then discovered the results to suit. Or am I being too cynical?

Irresponsible ‘communication’. Jimmy Boy, nobody’s listening any more. You’ve painted yourself into a corner. Wait for it to dry and surrender your brush.

The change of tone is interesting. Wasn’t the original argument that anything above 2C would be ‘dangerous’ to the planet? Now that the long term trend is closer to 1C per 100 years, this amount of warming must therefore be dangerous. But it’s already warmed by almost 1C and nothing bad has happened – in fact things have got a little better.
“Hansen said the paleoclimate record suggests that every degree Celsius of global temperature rise will ultimately equate to 20 meters of sea level rise.”
OK, we’ve had .8C in 100 or so years. When is the 16 meters of sea level rise supposed to happen? Is it still “in the pipeline” ?

tty

Hansen has alwas been, let’s say, Imaginative, when it comes to previous interglacial. As a matter of fact it is rather difficult to find any place on Earth where the Eemian wasn’t more than one degree warmer than the present.
The Greenland and Antarctic icecores which are otherrwise treated with the utmost reverence by Hansen shows that the temperatures were about 5 degrees warmer than at present, but ice losses were moderate.
Think about it, do you think that a 1 degree higher temperature would be enough for:
– hippopotamus in Yorkshire
– water buffaloes on the Rhine
– monkeys in Bavaria
– capybaras in Florida
– forests on the arctic coast of Siberia
all of which happened during the last interglacial

Truthseeker

The only source seems to be to quote Hansen. Talk about a circular argument. The skilled amateurs that post on this website do much more rigorous analysis than anything that has been done here. It must be the models telling Hansen there is a problem because I am not seeing any observational data being offered for review or cross-examination.

Bill Illis

One can show that Hansen is right.
All one has to do is throw out all the historical climate data and then make-up some new ones that show 4.2C per doubling of CO2. While that might not appear to be appropriate at first glance, it is done in the field all the time and is, thus, acceptable for publication / presentation at conferences.

GISS show Africa as one of the fastest warming places, yet have virtually no reliable thermometers to tell them. Yet satellites show warming there is much lower.
http://notalotofpeopleknowthat.wordpress.com/2011/11/21/giss-temperatures-in-africa-bear-no-resemblance-to-reality/

James Bull

I’ll put my tin hat on for when the sky falls.http://www.youtube.com/watch?v=w7RIgs3eygo&feature=related

Gareth Phillips

I suppose It depends on where you look and how the data is interpreted. Thats why I believe the science is a long way from being settled. Here’s some CET average data since 1970 showing variance. Although it’s only 40 odd years some of the records show pretty marked increases, one possibly equals tenth per decade, most don’t. But only one at present shows a fall., Maybe Mr.Hansen has data which show a more dramatic rise?
’71-’00 average N-W tracker
January 4.2C 4.15°C
February 4.2C 6.97°C
March 6.3C 7.2°C
April 8.1C 12.42°C
May 11.3C 12.91°C
June 14.1C 14.76°C
July 16.5C 16.03°C
August 16.2C 16.12°C
September 13.7C 15.71°C
October 10.4C 13.02°C
November 6.9C 9.94°C
December 5.1C 6.2°C

James

“If you tell a lie big enough and keep repeating it, people will eventually come to believe it. The lie can be maintained only for such time as the State can shield the people from the political, economic and/or military consequences of the lie. It thus becomes vitally important for the State to use all of its powers to repress dissent, for the truth is the mortal enemy of the lie, and thus by extension, the truth is the greatest enemy of the State.”