On May 9 CO2 reached 400 ppm at the National Oceanic and Atmospheric Administration’s (NOAA) monitoring centre at Muana Loa and at at the Scripps Institution of Oceanography in San Diego, California. This is what’s been happening over the last 130 years in broad terms:
It seems many news organisations, for example the BBC, and some scientists are stressing that the last time concentrations were so high was 3 to 5 million years ago. In the linked article Michael Mann, director of the Earth System Science Center at Penn State gives a different view:
Mann said the last time scientists are confident that CO2 was sustained at the current levels was more than 10 million years ago, during the middle of the Miocene Period.
Back then, global temperatures were hotter, ice was sparse and sea level was dozens of meters higher than it is today.
This graph gives an idea of how the temperatures played out over the last 65 million years:
I don’t think you can directly compare what the sea level would have been then with now because the shape of the ocean basins were possibly significantly different. Also I understand the error margins in ascertaining what it would have been then are quite high.
Nevertheless it’s no comfort that back then there would have been no Greenland ice sheet (worth 6-7 m) and little West Antarctic ice sheet (5-7 m). The East Antarctic ice sheet would have been smaller (59 m in all) and most likely there were no land glaciers and ice caps elsewhere (0.5 m). Thermal expansion would have also seen sea levels higher. So 25 to 30 metres seems about right.
Actually Aradhna Tripati and colleagues had a look at this back in 2009. They put equivalent CO2 concentration levels back 15 million years, but their story on ice and sea levels is much as I’ve just described. They put temperatures 5 to 10F (roughly 3-5C) higher. They produced this graph comparing palaeontological CO2 levels with IPCC forecasts:
This graph from the Mauna Loa site shows how the concentrations have stepped up over time:
James Hansen’s Iowa testimony (p39) tells us that during the Cenozoic era CO2 levels changed at the rate of 100 ppm per million years, that’s 0.0001 ppm each year. Now we are doing it about 25,000 times faster.
As Michael Mann said:
“There is no precedent in Earth’s history for such an abrupt increase in greenhouse gas concentrations.”
Finally there are other greenhouse gases. CO2e or CO2 equivalent covers what is sometimes known as the ‘Kyoto six’ under the Kyoto Protocol. The main ones other than CO2 are methane and nitrous oxide. This image from the World Resources Institute gives the mix as of 2005:
Unfortunately I can’t find current levels or historical graphs, but on that basis CO2e would now be 519. That can’t be good!
George Monbiot Climate milestone is a moment of symbolic significance on road of idiocy
The only way forward now is back: to retrace our steps and seek to return atmospheric concentrations to around 350ppm
George is his usual pessimist/realist self.
He sees our chances of preventing climate breakdown as close to zero.
So here stands our political class at a waystation along the road of idiocy, apparently determined only to complete the journey.
Update: Andrew Glikson has an interesting article at The Conversation. He’s an earth and paleo-climate scientist and as as such compares present CO2 levels with the Pliocene. With the temperature 2-4C higher and sea levels about 25m higher, it was a different place:
Life abounded during the Pliocene. But such conditions mean agriculture would hardly be possible. The tropical Pliocene had intense alternating downpours and heat waves. Regular river flow and temperate Mediterranean-type climates which allow extensive farming could hardly exist under those conditions.
I love that photo of earth from Voyager 1:
29 thoughts on “CO2 hits 400 ppm”
Well done, Brian – as always.
Joe Romm argues that it’s even worse than we think.
To those who remain unconvinced by the scientists, I say follow the money.
When you look at the trend indicated by the graph it is pretty clear that it is game over with Global Warming Action. We are heading for the worst of all options, and very rapidly. I think that my earlier guess at this that we have a maximum of 20 years of Global Economic Stability ahead of us.
That means that we have that much time to prepare a programme of national food security. The real risk items are broad field crops such as wheat, canola, corn, and other grains. You can write seafoods out of your future diet as ocean acidification will decimate shell fish, algal blooms will kill off near surface fish, and unchecked fishing will thin out the rest. Green vegetables and sugars will remain available as cane is very robust and vegetables can be grown under cover, but dairy will be less abundant.
The real risk is for city dwellers and surges of supply and famine. The problem is that violent weather events being ever more frequent will make it difficult for farmers to survive from one weather failed crop to another. People in the country, or at least people in the luchy parts of the country will not have food problems. People in the city, however, rarely have more than a week’s food on hand, and as the economy weakens this will become acute.
So even though it is about 10 years too soon for there to be any real need I am starting the process of learning how to preserve and store food. Woolworths and Coles greedy march for excessive profits have triggered a rash of food processing plant closures around Australia (I passed at least 2 on a Mothers day family picnic drive on up the Hawkesbury Valley) and this has to be making our national food production chain less robust.
So it is going to be stepping back in time 150 years in the interests of family survival. Preserving fruits and vegetables, storing grains, and growing greens in the back yard. We are just going to have to learn all over again.
I hate to raise this again, but given the current levels of CO2 are already too high for a safe climate and it will take too long to reduce them naturally, we’re going to have to seriously look at geoengineering.
Agree, Robert. The thing is that we will also need to insist that geo-engineering be considered as complimentary to emissions reduction, rather than a substitute for it as some would have it.
I think that you are dreaming on that score, guys, for all of the same reasons that CO2 emissions reduction has been ineffective.
The Mount St Helens explosion sent 1 cubic kilometer of ash into the atmosphere and had only a minor effect on atmospheric reflectivity. What would be done would have to keep being done for hundreds of years in a world where fossil fuel energy supplies are becoming ever more scarce while being utilised at the maximum extraction rate until fully exhausted. No doubt there are some who will suggest that this can be bridged with nuclear energy. I believe that would be further delusional thinking.
The other negative is that solar energy delivery to the surface would be reduced to some degree possibly affecting food production and solar electricity production, marginally.
The scale of geoengineering, I believe to be way beyond practical, political, or economic cooperativity limits.
BilB, I think we’ll have to pay more attention to food. I worry that food producing capacity gets wiped out by the competitive market, rather than an incapacity to produce. Then the infrastructure, such as processing facilities, goes down the shitter. We may regret this within a decade or two.
Like we don’t grow beetroot in the Lockyer Valley any more because the factory closed in favour of cheaper stuff in NZ.
Paul N, thanks for the link. I actually looked to see what Romm had to say and missed the post by minutes. I wish the US would join the rest of the world and use Celsius consistently. It would not surprise if climate sensitivity was revised upwards. I’m waiting to see what the IPCC has to say in the new report.
Robert, on geoengineering, there an article at The Conversation. The shorter message is that cooling the planet won’t do it and he thinks sucking CO2 out of the air is not much better:
Andrew Bolt three years ago:
The billion-dollar hoax. Here are just the top 10 new signs that catastrophic man-made warming may be just another beat-up, like swine flu, SARS, and the Y2K bug.
Andrew Bolt today:
10 signs the warming scare is dead. The 10 signs of the death of the scare are unmistakable. Now it’s time to hold the guilty to account.
Oh man. I am just laughing. Recycling his own failed predictions with ten new points, all just as bogus.
You’ll have to tell us what the 10 points are, indigo, as they are pay walled and there is no way I am paying $10 for Bolts twisted thoughts.
Bilb: Go to the paywalled link, grab the “teaser” paragraph text and paste it into Google. Follow the resulting link to the same article to overcome the paywall. You probably won’t want to bother in this case, but might want to in others.
One of Blot’s “10 points” (following the current fashion for Lists in articles, I see) is “people are relaxing”. (presumably having been fed tosh like Blot’s and having accepted it as fact.) Well, that’s scientific. I feel so much more relaxed myself, don’t you?
In my optimistic moments I think the world may be getting close to an action tipping point where the world lurches from doing not much to suddenly going on to a climate war footing. Several things are contributing to this optimism:
1. The growing number of climate crisis (such as hurricane Sandy) that people are starting to believe are being caused by climate change.
3. The clear melting of the Arctic – makes denialism harder and harder. Particularly given that scientists believe that this melting is driving all sorts of climate problems in the Northern hemisphere. (Sandy and heavy snow falls.)
4. The dramatic decline in the cost of renewable energy.
5. The reluctance of financiers to invest in fossil fuel.
Is Bolt ever rational on any issue at all? The body relaxes after rigor mortis has passed, maybe that is what Bolt is seeing. It tells you something about his sources.
I’m optimistic that Climate Action will get underway seriously too, but everything that we are witnessing tells us that what ever happens will take too long to ramp up to full effectiveness. There is far too much drive behind the CO2 injection rate and far too much elasticity in the efforts to curb fossil fuel use.
Taking a primarily market driven primary approach to carbon reduction was a massive mistake. It should have been an electricity use levy, funding market players to build renewable infrastructure. This in conjunction with carbon reduction incentives and penalties for non electricity industry sectors. This was Rudd’s failing and it was fully decided before the election in which he became the PM. I had a number of phone conversations with Albanese before the election and I could almost pick the date at which the path was set on Climate Change.
BilB, I thought the ALP climate policy was settled after a weekend seminar in early June 2007. It really depended on who was invited. Beazley had one, but that was set aside by the Ruddster.
Wow I feel a bit stupiderer for reading Bolts artickle. There’s a minute and a half of my life i won’t get back.
400ppm. Yawn. So what?
Without exception, all the models used by various cli-fi true believing AGW cultists to predict the ecopalypse have proven to be wrong. Sorry, chaps, the scam is ending, and the various con-men who profited by it are kicking back in their mansions counting the cash.
And no, I cannot be bothered debating with cli-fi true believers who deny the science which has demonstrated by measurement that the great glowball warmenating is not happening. It’s the modern equivalent of believing that the Earth is flat.
I see you’re fully doped up with Bolt for tonight’s comment attempt.
Its good, at least, that you are thinking about these things.
They’rer not thinking. They’re trolling.
I cannot be bothered debating with cli-fi true believers who deny the science which has demonstrated by measurement that the great glowball warmenating is not happening.
Not capable more like. You’re an idiot and you’re wasting our time.
Sorry, chaps, the scam is ending, and the various con-men who profited by it are kicking back in their mansions counting the cash.
I actually don’t get the constant Bolt references. It’s not a site I have time to frequent beyond the odd look.
What I do is actually read the current scientific papers. I changed my mind on AGW in 2002 when the fundamental flaws in the AGW computer models became obvious to blind Freddy, and have seen nothing since to offer any further support to the AGW hypothesis. The heat is not where it should be, according to the models, and actual measurement has confirmed that multiple times.
The debate has moved on, but please continue to believe whatever the hell you want. Its your cult, not mine.
Ok why is this study wrong?
Would you like to share with us the titles of your “scientific papers”?
There’s no point is there? As Jules notes “You’re wrong but I won’t discuss it” is not the sign of someone who knows what they are talking about.
Further evidence for that can be adduced as follows:
Suggestion that climate attribution depends wholly on models shows unfamiliarity with the science.
Allusions to the ‘tropical hotspot problem’ show inability to understand the science.
Rhetorical use of the term ‘hypothesis’ shows a lack of knowledge about science in general.
“The debate has moved on” shows a complete disconnect from climate science (which is doing just fine, thanks) and shows what ‘community of interest’ is being paid attention to.
Incidentally, the point is not to “believe whatever I want” but to be lead by the best assessment of the evidence. Accordingly I accept (provisionally, with possible revision in light of future evidence) the conventional science.
Mk50, if you read my link @2 you’ll find out where the real profits are being sought by governments and corporations investing lots of real money in the confident belief that the poles are melting.
My take is that once voters and governments reach a climate action tipping the action may be quite swift. (Think at the size and speed of reaction during WWll.)
– The BZE stationary energy plan talked about converting Aus to 100% renewable power within 10 yrs.
– If necessary, we could move to zero emission transport by simply replacing fossil transport fuels with renewable, low impact fuels (such as renewable gasoline) produced from water, renewable power and CO2 or nitrogen. These fuels can be produced without diverting land from food production or chopping down rainforest to allow the production of palm oil. (See: http://pragmatusj.blogspot.com.au/2013/03/renewable-low-impact-fuels-game-changer.html)
-The world economy needs a war on climate change to bring the world economy out of it’s chronic recession.
– Investors are beginning to realize that fossil fuel dependent industries have become high risk.
– Voters are getting sick of fossil fuel companies trying to tell them that BAU is all OK.
Andrew Glikson has an interesting article at The Conversation. He’s an earth and paleo-climate scientist and as as such compares present CO2 levels with the Pliocene. With the temperature 2-4C higher and sea levels about 25m higher, it was a different place:
I’ve added this as an update to the post together with the image of the earth form Voyager 1.
No you don’t.
I assess your source as Anthony Watts or worse, Joanne Codling.
No you didn’t.
Evidence for my assertions above. If you had read (and understood) the current scientific papers (as you claim) you could not have come to this conclusion.
Another extract from the Conversation article to ponder upon while considering the Budget. This is all restating the obvious,………but it must be done, a determination for real Climate Action will only be carried on the voices.
“When will we act?
The land, oceans and biosphere are now in extreme danger, but it doesn’t seem to be driving the global community to the urgent measures required for a meaningful attempt to arrest the current trend. With few exceptions, the accelerating rate of atmospheric CO2 hardly rates a mention on the pages of the global media, preoccupied as it is with short-term economic forecast, daily exchange rates, share market fluctuations and sports results.
In Australia the language has changed from “the greatest moral issue of our generation” to controversy over a “carbon tax”, diverting the public attention from the climate to a hip-pocket nerve. While we debate the ways to bring about a meaningless 5% reduction in local emissions, we simultaneously develop infrastructure to export hundreds of millions of tons of coal. It all ends up in the same atmosphere.
As Carl Sagan reminded us, on seeing a photograph of Earth taken from Voyager 1 as it left the Solar System
That’s here. That’s home. That’s us. On it everyone you know, everyone you love, everyone you’ve ever heard of, every human being who ever was, lived out their lives … Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity — in all this vastness — there is no hint that help will come from elsewhere to save us from ourselves.
I wen to this last night., delivered by yet another scientist terrified about our future. It was fascinating.
It used to be said we are at the end of the Earth. So maybe we are!
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