Sun May Be Warming Both Earth and Mars 1050
MCraigW writes "Simultaneous warming on Earth and Mars suggests that our planet's recent climate changes might have a natural — and not a human-induced — cause. Mars, it appears, has also been experiencing milder temperatures in recent years. In 2005 data from NASA's Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide 'ice caps' near Mars's south pole had been diminishing for three summers in a row. Habibullo Abdussamatov, head of the St. Petersburg's Pulkovo Astronomical Observatory in Russia, says the Mars data is evidence that the current global warming on Earth is being caused by changes in the sun."
RTFA (Score:5, Informative)
"His views are completely at odds with the mainstream scientific opinion," said Colin Wilson, a planetary physicist at England's Oxford University.
"And they contradict the extensive evidence presented in the most recent IPCC [Intergovernmental Panel on Climate Change] report."....
Perhaps the biggest stumbling block in Abdussamatov's theory is his dismissal of the greenhouse effect, in which atmospheric gases such as carbon dioxide help keep heat trapped near the planet's surface.
He claims that carbon dioxide has only a small influence on Earth's climate and virtually no influence on Mars.
But "without the greenhouse effect there would be very little, if any, life on Earth, since our planet would pretty much be a big ball of ice," said Evan, of the University of Wisconsin.
Don't forget the other planets and moon(s) (Score:5, Informative)
Triton - http://www.scienceagogo.com/news/19980526052143da
Jupiter - http://www.space.com/scienceastronomy/060504_red_
Re:Well Duh (Score:4, Informative)
Could be, but it's more likely that it's heat caused by the extreme pressure at the Earth's core caused by gravity...
RealClimate links (Score:5, Informative)
As usual, some useful discussion of these issues can be found on RealClimate.org. The following two articles are worth a look, though neither is especially recent:
The punchline from the latter article is, "There is a slight irony in people rushing to claim that the glacier changes on Mars are a sure sign of global warming, while not being swayed by the much more persuasive analogous phenomena here on Earth..."
Re:RTFA (Score:2, Informative)
http://www.epa.gov/methane/scientific.html [epa.gov]
so at about 1700 ppb (billion) or 1.7ppm at about 21 times greenhouse effect than CO2.
CO2 concentrations are at 380ppm (million),
http://cdiac.ornl.gov/trends/co2/sio-mlo.htm [ornl.gov]
So methane "heat trapping equivalence" would be 1.7ppm*21 => 38ppm CO2. CO2 is at 380ppm or 10X that of methane equivalent. So, methane does not account for the greenhouse. It only accounts 10% of the greenhouse effect.
Oh, and since you are comparing uneducated people with idiots, then you must be a big one. Methane *used* to play the vital role in keeping Earth warm. That was, 4 billion years ago. As soon as oxygen jumped to ~0.1% or 1% of atmosphere, methane disappeared and CO2 became THE major source of keeping the Earth warm. That disappeared about 500 million years ago when O2 spiked to over 20% (quickly - plants developed). Each of the events caused Earth to freeze for some time. Anyway, I'm sure you'd not research these facts either... (facts - they are in rocks!)
Re:RTFA (Score:5, Informative)
I really love how people like you sit here and blast the work of scientists, even saying they are "idiots that don't know what the hell they are talking about", pounding on them for pushing an agenda, when it's perfectly clear that you yourself have an agenda of your own and no understanding of the immense amount of research that's been done on the subject.
Re:Well Duh (Score:3, Informative)
The second law of thermodynamics [wikipedia.org] disagrees. Heat moves from hot things to cold things, not the other way. In order for heat to flow from the outside of the beer cooler to the inside, the outside would have to be hotter than the inside. If the inside was hotter, heat would flow out, not in.
Re:RTFA (Score:5, Informative)
http://www.mpg.de/english/illustrationsDocumentat
Re:How long do we have to argue about the why... (Score:3, Informative)
1) The Earth has been warmer than it is now before! We are not seeing temperatures outside the spectrum of nature, and even assuming worst case according to the IPCC we won't be outside normal for more than 500 years.
2) CO2 levels are not high now. There was an article in Scientific American which documented this, CO2 over the last 2 million years has fluctuated between ~200ppm and ~1400ppm. Right now we are at about 300ppm.
3) The Sun and the Orbit of the Earth both fluctuate and are beyond our control and both influence the climate much more than anything we could possibly do.
4) The Earth has been through many cycles of ice age and temperate age all before we were here.
5) The last temperate age melted almost all of the polar ice and caused sea levels to rise 4-6 meters this was 125k years ago. It is safe to assume it will happen again (with our without us)
6) We are still coming out of the last ice age, and we haven't seen temperatures comparable to the last temperate age yet, so we can easily assume temperatures still need to go up before the cycle starts again.
These things are completely beyond our control, if we spend billions (and I'd argue it would cost many trillions) to "fight" global warming, well if you want to fight against the solar system, go ahead but I'm not giving you my tax dollars to do it.
Re:Yes, the Sun goes through cycles (Score:1, Informative)
However the solar constant, the solar electromagnetic (light) output integrated over all wavelengths from -infinity to +infinity is remarkably constant, to within a fraction of one percent. Instruments such as ACRIM (Active Cavity Radiometer) flown on successive space missions have demonstrated quite clearly that the variation in the solar energy output is very much less than the increase in the global mean temperature.
This is not to say that the increase in global mean temperature is or is not due to anthropogenic sources. That is what the debate is all about. But we can rule out changes in the sun as being the cause of these variations.
Main sequence evolution (Score:5, Informative)
--
Solar: It's steady. http://mdsolar.blogspot.com/2007/01/slashdot-user
Re:Woo! (Score:4, Informative)
That 1% of total greenhouse gases in the atmosphere can be significant dependant upon the effects. Given that 'natural' greenhouse gases contribute around 33 degrees C (IIRC) to average temperature as is, even just a few percent increase over norm could result in a significant average temperature increase. Significant in this case being potentially enough with other feedback factors and criticalities to cause climate shift. Also, that 1% addition is mostly of gases with long lifespans as far as the cycle of the atmosphere goes. Seabed evidence seems to indicate the recapture timespan of a massive release of carbon at shortest (again from my recollection) of 5,000 years. So, even just a 1% per year release over the normal sources with only a 1,000 year for the biosphere to recapture would put CO2 levels at about double after a century. Note: This is not an actual calculation just an example to show that even the numbers you post could be significant in a longer term scale.
Water vapor tends to balance out to normal levels in the order of weeks instead of millenia (as is the case for CO2 and other such forcing inputs). Thus, water vapor is an important factor in an amplification sense, but not so much in terms of the amount added to the atmosphere for determination of climate change.
The problem with most climate change denial arguements is the lack of quantitative analysis. So while they may seem sound at first, they tend to be factors that are already counted into the overall physics. Attempts to characterize the science or scientists as political or ideological are ad hominin attacks at best. The science and data are there, if you or anyone else truly has a better explanation for the data you are more than welcome to submit your theory/evidence... the only criteria that is has to withstand scientific scrutiny.
TFA is a troll. (Score:3, Informative)
Your post is not a troll but TFA certainly is.
For anybody wondering about the attribution of various +/- forcings affecting climate, including variations in solar flux, please see figure SPM-2 in the 2007 IPCC SPM report. For those who like the Mars idea as expressed in TFA please explain why 3yrs of data should be accepted as a trend, let only accepted in preference to a theory that has made some accuate predictions and has an observational record that uses multiple idependent lines of inquiry for periods that are up to a few orders of magnitute longer?
Only with Abdussamatov's patented Space Limbograph (Score:4, Informative)
Space Solar Limbograph [cambridge.org]
I am not making this up.
Re:CO2 least of my worries (Score:3, Informative)
Re:Well Duh (Score:2, Informative)
Yes, but this is not just a thermodynamics problem because of the radiation from the sun. The temperature of the earth is much hotter than the temperature of outer space surrounding it, just like a cooler or a car can get much hotter than the ambient temperature of the air because the sun is heating it faster than it can radiate heat out. A good model of the earth would be a clear cooler (the earth's atmosphere) and black beer cans (like Guiness or something). The sun would heat up the beer cans directly, and the cooler would keep the heat from escaping. Put that in the sun and it'll get much hotter than the ambient air.
Re:Well Duh (Score:2, Informative)
It's quite possible for insulation to trap radiated heat, making objects warmer than their surroundings. Greenhouses are designed to do just that, which is why they call it the "greenhouse effect".
Re:Renewable Energy even w/o global warming (Score:3, Informative)
The point is that North America peaked in Natural Gas production in about Jan 2001. I suspect the world may be peaking in oil production and may already be past peak. We do have coal available and we do have nuclear. But most houses don't have a coal furnace anymore.
If we start building the IRF reactor system which was designed by Argonne Labs (and shut down by clinton's administration in 1994!) then we have over 60,000 years of uranium supply on hand already mined... this for a fleet of about 110 reactors. North American can produce 100% of its power from nuclear - but we need about 1200 reactors to do it. We havn't started to build any. Any new reactors are years away.
Then we have the biofuels people. If we take ethanol for instance, it can be produced from pretty much any plant material. Plants are sugar polymers for the most part. We can break these polymers down. This is what fungus do and this is what yeast does... its just yeast needs to start wtih pretty simple sugars whereas a fungus like Trichoderma reeshii can break down celulose and this is why its used to make stone washed bluejeans. How effective T. reeshii will be in celulose to ethanol production is open and then we have that about 50% of plant material is not cellulose but instead is ligins and pentosans - which fungus like Pleurotus and Lentinula spp (and many other species can digest). Whether they will produce alcohol is an open question.
Ethanol from grain is viable. To do this cost effectively is equaivalent to brewing beer at $2.50 per keg. To produce all the liquid fuel North America needs we would need to consume more than the worlds production of grains. Please note: One tonne of dry plant biomass is equivalent to about 2 barrels of oil and this is if we can convert it for free.
So, I'm not particularly worried about CO2 levels. CO2 is a fertilizer and encourages plant growth. I am however quite worried about fuel supplies in the not too distant future and I think we are already starting to see supply constraints.
People should start by doing what they can... like insulate their houses for instance. Instead people run around and point their fingers at CO2 levels (and understand practically nothing about it). Heating houses creates CO2 - so why won't they do something that they can do and save themselves money in the mean time? Are they bound and determined to freeze in the dark?
My father who has now passed on is an example. He refused to properly insulate his house. When I grew up and it was 40 below outside there was frost on the walls of the bedroom. He put in an oil furnace about this time and was burning a tank up every 3 weeks. He'd been told oil was cheap and insulation was expensive I guess. I was pretty little but still old enough to remember the 1 1/2" of rock wool he was putting in the walls and I asked him why he didn't fill the whole wall up? He said it was not "cost effective". That xmas my mother and father were looking at their oil bills wondering how they were going to heat their house.
At this point, that house is going through 18 cords of wood per year. It is still not insulated.
A similar size eco-designed house is using 3/4 of a cord per year.
This is what insulation and good design can do. It doesn't cost much extra to build it right in the first place. For instance, R50 fiberglass in the walls will cost about $1 buk per square foot during the construction phase. After the house is finished you need to tear walls down.
If houses in North America were properly insulated they would be much cheaper to heat and much more comfortable to live in. So why won't people do it? It will greatly reduce CO2 emissions.
What really worries me is what the next generation is going to do. Gas hit $17 bux on the Henry Hub a little over a year ago. Next year it might hit $20 bux. While we have a short reprieve, I am personally close enough to the Oil and Gas business t
Re:Woo! (Score:5, Informative)
http://volcanoes.usgs.gov/Hazards/What/VolGas/vol
"Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1999, 1992). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 22 billion tonnes per year (24 billion tons) [ ( Marland, et al., 1998) - The reference gives the amount of released carbon (C), rather than CO2.]. Human activities release more than 150 times the amount of CO2 emitted by volcanoes--the equivalent of nearly 17,000 additional volcanoes like Kilauea (Kilauea emits about 13.2 million tonnes/year)!"
Go back to physics class (Score:5, Informative)
No offense, dude, but go take a physics class. That goes for whoever modded _that_ "informative" too.
1. Heat flows from the sun to the earth, and from both to the vast expanses of open space anyway. It's not the outside space that's heating the Earth, but the Sun.
2. The laws of thermodynamics have to do with atom/mollecule movement, and transfer of heat between bodies in contact. The only (ok, vast majority of) energy flowing in or out here has _nothing_ to do with thermodynamics as such, since there are no two bodies in contact exchanging heat (i.e., exchanging mollecule movement by impact.) What is happening there light being absorbed and radiated, and yes that can happen in the opposite direction just as well. There are relevant laws there, e.g., Stefan-Boltzman [wikipedia.org], but the second law of thermodynamics isn't it.
E.g., you can cut sheet metal with a focused laser beam even though the heated point is basically a hell of a lot hotter than the laser. It will absorb the light anyway. E.g., to address your "inside" and "outside" concerns, you can fry an ant with a magnifying glass even though the ant ends up hotter than the surrounding air. That's because the energy comes from the sun, not from the outside air.
So, sorry, the GP post was right, you are wrong.
But to get back on topic, what's happening is that the earth receives some radiation energy from the sun, and it radiates some back into space. The equilibrium temperature is when the energy radiated equals the incoming energy. Basically if energy E is incoming, then the equilibrium temperature T is when surface times emissivity times Stefan-Boltzmann constant times T to the 4'th power equals E. That's all.
The "insulation" and its non-uniformity across wavelengths messes things a little, but as long as the temperature variations are relatively small, the wavelength don't shift horribly much, so basically the proportionality stays. And a global warming of 1 Celsius (which at least at one point was all the heating Earth had experienced) isn't enough to throw it off the hook. If the Earth's temperature is, say, approximately 300 Kelvin (for the sake of a nice round number), we're talking a third of a percent increase. Since the rest is constants T1^4/T2^4=E1/E2, so it only takes an increase of (1.00333)^4=1.0134, or 1.34 percent increase in incoming energy to fully explain it. Better yet, since Stefan-Boltzman applies to the Sun too, to fully cause it, the Sun would have to experience the same heating the Earth does. A third of a percent heating of the sun creates the extra energy to heat up the Earth by a third of a percent.
So that's basically all the debate here: did our "insulation" change over time, or is it simply that the Sun got slightly hotter? The former wouldn't explain why Mars is heating up too, while the latter fully does.
Funny the things one can learn by paying attention in physics class, really.
Re:How long do we have to argue about the why... (Score:5, Informative)
The Stern report, authored by the former World Bank chief economist, says more like 1% of global GDP to prevent a 10-20% drop due to warming [bbc.co.uk].
The Earth has been warmer than it is now before!
I suppose if a huge asteroid were on course to hit Earth, your argument would be "the Earth has been barren and molten rock before! let's not do anything!"?
CO2 levels are not high now.
CO2 levels in the last 720,000 years never went over 300 as we know from the EPICA ice cores. We're over 375 right now [wikipedia.org].
I love that you're smarter than thousands of climate scientists, essentially every relevant scientific organisation, and the 154 nations who had to unanimously sign off on the IPCC's conclusion that there's a 90% certainty that human activity is causing warming at least in part. When's the Nobel being awarded?
Re:CO2 least of my worries (Score:4, Informative)
Actually, as Gore pays higher electrical rates to get clean power, those coal plants aren't doing anything on his behalf.
Oh, and according to the power company, the one-man think tank who issued your talking point is full of shit [yahoo.com].
"Johnson said his group got its figures from Nashville Electric Service.
But electric company spokeswoman Laurie Parker said the utility never got a request from the policy center and never provided them with any information."
Re:Renewable Energy even w/o global warming (Score:3, Informative)
I agree that nuclear is the way to go to reduce CO2 and preserve our lifestyle and economies, but the Argonne reactor type is actually called IFR 'Integral Fast Reactor'. Read more about it here:
http://en.wikipedia.org/wiki/Integral_Fast_Reacto
In todays 'climate' (no pun intended) that project should be revived immediately.
Our whole electricity usage could be converted to nuclear, our heating could be converted to electric. That would cover about 2/3 of our CO2 output (numbers for the UK). Serious attention to 'plugin hybrids' ( http://www.calcars.org/vehicles.html [calcars.org] ) could convert a lot of our consumer car miles to electric as well. Where are we at? 80% reduction already? The LA smog won't be the same...
X.
Comment removed (Score:3, Informative)
Re:How long do we have to argue about the why... (Score:5, Informative)
No, it's not. They're predicting 4-30 [wikipedia.org], and they've been widely criticised for being too conservative on the issue - ignoring unusually fast melting in Antarctica and Greenland, for one thing.
Sure if sea levels rise 6m it will displace quite a few people, but I still don't think it would cause that much upheaval.
10% of Bangladesh would be under water with a 1 meter sea rise. That's about 15 million refugees in one nation alone, and you can be sure Bangladesh can't afford to pay 10% of their population's land just to let it get eaten up by the ocean.
A 6 metre sea rise would also destroy Miami and a number of other major cities on the East Coast of the US. We're talking about pretty huge repercussions with that big of a sea rise.
The Stern report isn't just pulling numbers out of their asses.
As far as the asteroid is concerned what would your recommendation be?
You're missing my point. The OP stated that the Earth had seen much higher CO2 in the distant past. My point is that just because it has happened previously doesn't mean it'd be fine if it happened again - after all, the Earth started up molten and airless, but that wouldn't be conducive to human survival today.
That is what you environmentalists don't get, you never factor in risk/reward
Again, read the Stern report. For a 1% cost of GDP we protect 10-20% of GDP. How is that not factoring in risk and reward?
On the CO2 front I guess Scientific American got it wrong then I'm just quoting their article verbatim... So either they are lying, or you are, but whatever.
If you have the article in front of you to quote from, surely you can provide a citation?
I'm reasonably sure I'm not lying, and so is NOAA: Vostok's 420,000 years of data [noaa.gov] and EPICA's 650,000 years of data [noaa.gov], for your perusal
The IPCC did not state anywhere any sort of statistical probability as you state.
http://www.google.com/search?q=IPCC+90%25+certain
" The scientists said it was "very likely" -- or more than 90 percent probable -- that human activities led by burning fossil fuels explained most of the warming in the past 50 years.
That is a toughening from the Intergovernmental Panel on Climate Change's (IPCC) last report in 2001, which judged a link as "likely", or 66 percent probable." - http://in.today.reuters.com/News/newsArticle.aspx
How does that not support my statement, quoted as follows: "there's a 90% certainty that human activity is causing warming at least in part"?
I don't see #1 - the 60% chance figure - in the 2006 IPCC report. Sure you're not looking at the 2001 report?
Re:ya but.. (Score:4, Informative)
http://volcanoes.usgs.gov/Hazards/What/VolGas/vol
>snipComparison of CO2 emissions from volcanoes vs. human activities.
Scientists have calculated that volcanoes emit between about 130-230 million tonnes (145-255 million tons) of CO2 into the atmosphere every year (Gerlach, 1999, 1992). This estimate includes both subaerial and submarine volcanoes, about in equal amounts. Emissions of CO2 by human activities, including fossil fuel burning, cement production, and gas flaring, amount to about 22 billion tonnes per year (24 billion tons) [ ( Marland, et al., 1998) - The reference gives the amount of released carbon (C), rather than CO2.]. Human activities release more than 150 times the amount of CO2 emitted by volcanoes--the equivalent of nearly 17,000 additional volcanoes like Kilauea (Kilauea emits about 13.2 million tonnes/year)!
Re:Stand and deliver! (Score:5, Informative)
In 1859 John Tyndall discovered the radiative forcing effect of water vapour, carbon dioxide, and ozone [for the details see James Rodger Fleming, Historical Perspectives on Climate Change (New York and Oxford: Oxford University Press, 1998)]. He later postulated that changes in the atmospheric concentrations of these gases may be responsible for climate change.
His lab work showed causation, not correlation.
*sighs at the general ignrance of the loudmouths on here*
empty vessels indeed...
Re:All I have to say is... (Score:2, Informative)
Actually since Pluto is moving further away from the Sun and continuing to warm despite that fact, it indicates that something doesn't fit the "Constant Solar Constant" BS
So you've failed the reading test. Will we get a conspiracy theory?
These articles in no way supports your "OMG it's a conspiracy!" distortion field, unless you believe the astronomers are in on it with the climatologists and geologists.
I didn't posit a conspiracy since the astronomers are simply reported experimental results. By no means do all or even most astronomers believe the global warming hysteria, nor all climate scientists.
Also, if you bother to check your history, James Hansen didn't pull this out of his ass and a bunch of climatologists suddenly said "Brilliant! We can finally crush ExxonMobile/Shell/BP/Chevron!!!".
I didn't say that he did then, although he has exactly no scruples about doing it now. Nevertheless the decision to back the greenhouse theory was a political decision taken during the Carter administration, as described in a book called "The End" published in 1988.
He also has no scruples about rewriting recent climate history [climateaudit.org] making the late 20th Century warmer and the early 20th Century colder. This isn't conspiracy but cold hard fact. History being rewritten according to a hypothesis. It's just like Wikipedia.
There was quite a bit of review and discussion early on, it's just that the theory that best explained the observations survived, which is how good science works.
Actually it survives not because it makes the best observations (it doesn't) but by a scorched earth policy of accusing any critics of complicity with Big Oil or the Republican Party. Comparisons with Holocaust Deniers abound, and Hansen keeps altering history to fit his pet theory.
Re:Stand and deliver! (Score:4, Informative)
http://www.ncdc.noaa.gov/paleo/vostokco2.html [noaa.gov]
From the abstract:
"High-resolution records from Antarctic ice cores show that carbon dioxide concentrations increased by 80 to 100 parts per million by volume 600 +/- 400 years after the warming of the last three deglaciations."
You get that? CO2 increased 400-600 years AFTER the glaciers receded.
This is why when certain scientists graph the CO2 data from the Vostok ice cores, they never overlay temperature on the same graph: http://www.worldviewofglobalwarming.org/pages/pal
Re:ya but.. (Score:3, Informative)
I cool water in a controlled laboratory experiment, and it freezes. Water in the real world
There are many variables in the Earth's climate, but none of them change the fact that CO2 and other gases produce a greenhouse effect, and they don't change the magnitude of that greenhouse effect. Those are physical facts.
The uncertainties are not in the greenhouse effect. The uncertainties are: how much warming and cooling is there from other sources, and how much do feedbacks amplify those effects.
Re:ya but.. (Score:4, Informative)
The uncertainty is not about whether CO2 in the real atmosphere causes warming. It's about the warming and cooling contributions from other sources — how much of the total warming can be attributed to each source. (The direct contribution from CO2 can be calculated directly from adsorption physics, but there is uncertainty about how feedback effects amplify its contribution, as well as the contribution of other sources.)
There is not now enough remaining uncertainty to attribute global warming to non-CO2 sources; see the IPCC estimates in Figure SPM-2 of their latest publication.
Re:Stand and deliver! (Score:3, Informative)
Re:Stand and deliver! (Score:2, Informative)
Re:All I have to say is... (Score:4, Informative)
I work for one of the leading global suppliers of meteorological equipment. The issue isn't with how accurate the sensors can be, it's if they are being properly calibrated and maintained. In the US we do a fairly good job, although if a sensor is reporting off by a degree or two it is within accepted functional range and will pass any inspection.
Re:ya but.. (Score:3, Informative)
Who's arguing that?
I've seen a few people in this very thread arguing that, although the person I was responding to above to actually meant something else, if you look at the replies. But look around: you'll see people who insist that just because we can measure the greenhouse properties of CO2 in lab, doesn't mean that the greenhouse effect actually works in the atmosphere.
In fact, the scientist being discussed in this thread also denies the greenhouse effect, with some mumbo-jumbo about how CO2 rises in the atmosphere and releases all the heat it has stored.
Is the planet getting warmer? This is the only "consensus" that exists, and even that one isn't so monolithic when the question of "over what time period" is addressed. By itself, this is nothing new; the planet is dynamic and will always be changing.
That's true, but it's also true that we are causing an accelerating warming right now and have been for a century or so, which is not necessarily something we would prefer to happen.
The implied premise that there exists some sort of ideal state for the planet and that any change from that state is a Bad Thing, is the enviro-cult's equivalent of the Eden myth.
There is no such premise. It is, however, a fact that civilization on Earth right now is adapted to a particular climate, and there are costs to adapting to a different climate, especially when the climate change is rapid.
Is the warming being driven by the CO2 input? There is no consensus whatsoever on this point, as it hinges on how dominant that input is.
Far to the contrary, there is a widespread scientific consensus on this point. Pretty much the only people who dispute it are American conservatives.
From what I've seen, it's a pretty small one, likely negligible.
On the contrary, it is the dominant factor. It's pretty obvious that "what you've seen" on the matter does not include any actual climate science.
Try reading the IPCC FAR SPM (here [www.ipcc.ch]), such as Figure SPM-2. The increase in CO2 forcing is very large compared to the other changes in forcings over the industrial period.
We already know that CO2 is swamped out by H2O on that front.
Wrong.
I get really tired of explaining this, but here goes again:
There is more H2O in the atmosphere than CO2, but that doesn't mean that global warming is attributable more to H2O than CO2. The H2O in the atmosphere provides much of the baseline natural greenhouse effect, which totals about 30 C, and explains why the planet is not a frozen iceball. To understand the warming that has occurred since 1850, which is a change in temperature (of about 1 C), you have to see what has changed since then. The change in CO2 far outweighs the change in H2O, and is responsible for most of the change in temperature.
IMO the presumption that all other inputs have been steady-state is absolutely preposterous.
There is no such presumption, once again pointing to your total ignorance of climate science. But hey, whatever reinforces your ideology.
In point of fact, climate models use variable time series for solar irradiance, anthropogenic and natural aerosols and particulate matter, anthropogenic and natural greenhouse gas emissions, the carbon cycle, land use change, and so on. They do not fix the inputs as "steady state".
Will the consequences be catastrophic?
Probably not, unless Greenland's ice destabilizes more readily than we thought (which is possible, there is unexplained rapid ice loss going on, but if it happens it probably won't be for a few centuries).
It will, however, likely be economically unfavorable, and even hardline economists who specialize in climate change agree with that. It's not going to be so unfavorable that we need to cut all emissions, but all the o