Editorial viewpoints from Climate Central's writers and editors.

Hold Your Rejoicing About Those Falling CO2 Emissions

By Michael D. Lemonick

Remember global warming? You know, that worldwide disaster we were all so worried about way back in 2011? It wasn’t an unreasonable fear, of course: the world has been pumping greenhouse gases (especially carbon dioxide, or CO2) into the atmosphere like there was no tomorrow. Greenhouse gases trap heat. Ergo, said both the theory and the evidence, global temperatures are heading upward, forcing ice to melt, sea level to rise, and extreme weather to come along more often.

But all of that is so last year. The Associated Press is reporting  a “surprise turnaround” in carbon-dioxide emissions. Based on a document from the federal Energy Information Agency, the AP points that CO2 emissions have fallen to their lowest level in 20 years — and it’s not because of any new government regulations, but rather because natural gas has replaced coal in many power plants. Gas emits much less CO2 than coal, and thanks to fracking, gas has become extraordinarily cheap and plentiful. Problem solved! Or at least as the headline more responsibly puts it, “some experts optimistic on global warming.”

Natural gas pipeline. 

Really? These experts might want to think again. It’s true that natural gas emits about half as much CO2 as coal in producing a comparable amount of energy, but half as much isn’t zero, and zero, or as close to it as is humanly possible, is where the world needs to get in a big hurry.

The reason: a large fraction of the carbon dioxide we put into the atmosphere is going to stay there for thousands of years. Even if we were to cut off emissions completely right this minute (an obviously impossible and absurd notion) atmospheric CO2 levels would drop excruciatingly slowly, and they’d be trapping extra heat all the while. The only way to avoid permanent and dramatic changes to the climate, argued NASA scientist James Hansen in 2008, would be to limit carbon concentrations to 350 parts per million — or, since we’re already up to about 395 parts per million, to bring them down quickly to that level. (For comparison, the level before we began burning fossil fuels in earnest in the early 1800’s was about 270-290 part per million).

If that’s the case, then natural gas is hardly an answer. As scientists Ken Calderia and Nathan Myhrvold showed in a paper earlier this year, gas can ultimately cut emissions, but during the time you’re building the plants — a process that itself takes substantial energy — you’ve added so much more CO2 to the air that, as Myhrvold told Climate Central, “It’s like living on a credit card. It’s easy to get into a situation where it will take years and years to pay back.” It’s not just the CO2, either: drilling for natural gas releases substantial amounts of methane, which is an even more powerful greenhouse gas than carbon dioxide.

Besides, the boom in cheap natural gas isn’t going to last forever. As the AP story noted, “. . . changes in the marketplace — a boom in the economy, a fall in coal prices, a rise in natural gas — could stall or even reverse the shift. For example, U.S. emissions fell in 2008 and 2009, then rose in 2010 before falling again last year.”

Here’s another sour note: emissions may be on the decline for the moment in the U.S., but they’re still rising worldwide, so the atmosphere’s CO2 burden, with all those hundreds or thousands of years of heating that implies, is still getting larger.

And here’s yet another: the natural gas boom may be depressing the market for truly renewable forms of energy like wind and solar — the kind that put out zero carbon emissions whatever. It’s quite true, as University of Colorado environmental policy expert Roger Pielke, Jr., said in the AP story, that “if you make a cleaner energy source cheaper, you will displace dirtier sources.” But you can clearly also displace even cleaner sources.

To sum up: emissions have dropped in the U.S., thanks to a form of energy that’s ultimately not much cleaner than coal, and which has stalled conversion to truly clean energy. Meanwhile, worldwide emissions are still growing, putting CO2 into the atmosphere as though it were some sort of global Roach Motel where molecules can check in, but they can’t check out.

This may make some experts optimistic. It doesn’t do a lot for me.

« Commentary


By climatehawk1 (Norwich VT 05055)
on August 17th, 2012

Thanks, nice job.  It was a pretty amazingly slanted story.

Reply to this comment

By M Tucker
on August 17th, 2012

Thanks for this outstanding post! Yep, emissions are rising worldwide. Coal is still the preferred fuel in China and India where the demand for electricity is still growing. Another misleading headline from the abysmally poor news media. If it weren’t for sites like this, science magazines, and a few climate activists, the general public would be even less informed.

I would like to comment that even thought I know you, Michael, are aware of this some mistakenly believe that if we just cut our emission, say 50% by 2040, we will be ok and that will allow CO2 levels to come down to 350 and then we can moderate our fossil fuel diet to keep it there. Like a weight loss program. So I would like to emphasize what you have said above.

We cannot limit carbon to 350ppm because we have passed that mark and that carbon “...is going to stay there for thousands of years. Even if we were to cut off emissions completely right this minute…” You cannot get to 350 or below by limiting emissions. You must end emissions and allow nature to “drop [them] excruciatingly slowly” while they trap “extra heat all the while.”

It will be a long, long time before we cut off emissions so we must begin to plan for the very worst predictions that Dr Hansen and others have made.

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By Windy
on August 17th, 2012

Michael since there are positive feedbacks associated with CO2 forcing is it fair to also include the reduction of those positive feedbacks in calculating the benefits of gas over coal in terms of net warming? Have you thought about that? TIA

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By Andy Revkin (Garrison, NY, 10524)
on August 17th, 2012

Great reminder of the issues that arise because of CO2’s long greenhouse tail, once released. But it’s important to consider that China shows every sign of following (with some lag for various reasons) the US lead on gas-to-coal shift. The air pollution crisis there gives added impetus to do so. A rapid China shift to gas from coal could provide a breather of sorts. http://dotearth.blogs.nytimes.com/2012/07/04/a-greenhouse-gift-if-china-follows-u-s-shift-from-coal-to-gas/

MIT has a report stressing the importance of using policy shifts to sustain rate of advance in nonpolluting energy choices even with cheaper gas. http://globalchange.mit.edu/files/document/MITJPSPGC_Reprint_12-1.pdf

All such steps will require smart policy choices with climate in mind - and that’s no easy task. But I for one see reasons for optimism.

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By Jack
on August 18th, 2012

With CO2 levels at the current mark, we’re headed for the disaster that Hanson predicted.  The only questions are how soon will it hit and how will we adapt.  Clearly, gas is not the solution to heading off the parched earth ahead.  Reducing our per capita energy demand and going to alternatives asap must be the primary strategies.  However, in the US, neither the public nor politicians are ready to truly commit to either. 

While we do our best to ramp up both energy austerity and green energy, we need to slow down the accumulation of GHG’s in the atmosphere.  Natural gas is emerging as the only viable transition fuel.  This comes with the very high price tag of environmental risk and delay of both alternative energies and robust energy conservation and efficiency programs. 

Given that the Pandora’s Box of natural gas is open wide and not closing again, we have to figure out how to manage both of those risks.  As importantly, we must anticipate the realities of a world that is much hotter and start adapting to that world now.

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By George Ennis (Toronto, Canada)
on August 18th, 2012

The problem with looking at natural gas as a solution that will buy us time to deal with climate change is that the investment required to extract and distribute natural gas from the well to the consumer will have the effect of “hardening” emissions of GHG albeit at a lower level.

The hardening of GHG emissions from natural gas comes from the fact that we will have to make investments that may well total in excess of $1 trillion to explore for and distribute natural gas. The hardening comes from the fact that we would then shortly having completed the building this infrastructure over the next 2 decades then start the process of decommissioning/abandoning it. If you thought the fossil fuel industries are putting up a fight now the fight in the future would be even more ferocious.

Assuming we could overcome the resistance from these financial interests, how long would it take to deploy solar and wind technologies? Would we have the financial wherewithal to finance it, given that we would be diverting enormous resources towards adaptation of other parts of our public and private infrastructure?

Essentially, I suspect if we opt for wide spread development of natural gas as a policy to deal with climate change we will fall into what has been ascribed to other failed civilizations as a progress trap i.e. we trade short term progress for long term pain. Many civilizations have fallen into progress traps in the past i.e. Mesopotamia which used irrigation to expand its agricultural base but which ultimately led to increased salinization of farm fields which affect the region to this day.

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By Danny (75961)
on August 18th, 2012

Wow, the Hansen suck up continues on unabated.  Guess the science is “settled” again.  Where are the opposing views?  CO2 in the atmosphere is not a bad thing.  Despite belief to the contrary, it helps green stuff called vegetation grow.  That includes food.  We are in a warming period, due mainly to the sun being in a max cycle.  I guess all those SUVs on mars, jupiter, and saturn have heated them up too.  Or is this data being ignored so foregone conclusions fit?

I was around in 1977 when climatologists declared the world was about to end due to one cold winter.  Today, there is apoloxy for one hot summer.  A summer much less hotter than during the dustbowl years. 

I, for one, am tired of all the doomsayers.

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By Buzz Corry (Independence, MO 64055)
on August 18th, 2012

“A large fraction of the carbon dioxide we put into the atmosphere is going to stay there for thousands of years. Even if we were to cut off emissions.”

With burgeoning population growth, the only way for man to survive is to flee this planet.  Instead of foolishly trying to control CO2 emissions, we should be putting our money into space exploration.

By 2050, the world will host nine billion people””and that’s if population growth slows in much of the developing world. Today, at least one billion people are chronically malnourished or starving. Simply to maintain that sad state of affairs would require the clearing (read: deforestation) of 900 million additional hectares of land, according to Pedro Sanchez, director of the Tropical Agriculture and Rural Environment Program at The Earth Institute at Columbia University.  To feed them, we will need to convert more forests to agriculture. 

Agriculture””thanks to deforestation, nitrous oxide from fields, methane from cattle and rice paddies””is responsible for one third of global greenhouse gas emissions from human activity, making emissions from transporting food, known as “food miles,” a “rounding error,” said ecologist Jonathan Foley, director of the Institute on the Environment (IonE) at the University of Minnesota. Pasture has become the dominant ecosystem on the planet, he added, and humans directly employ some 40 percent of the surface of the planet. “Very little of that is urban.”

In addition, agriculture accounts for at least 85 percent of human water consumption””a growing concern as aquifers diminish and hydrology changes in the face of climate change.  See Another Inconvenient Truth, by
David Biello, Scientific American

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By Fessee Diriger (Boston/MA/02178)
on August 18th, 2012

Great idea! Let’s get to ZERO CO2. We can all become hunter-gatherers using stone tools, and even avoid fires by moving to warm climates!

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By Ann Banisher (San Diego, CA, 92103)
on August 18th, 2012

So what you’re saying is’ life is a swirling, sucking eddy of despair filled with brief moments of false hope in an ever blackening universe’
There is much more potential CO2 to be saved by replacing coal with gas than with wind. It is expected that over 27 gigawatts of coal energy is to be retired in the next 5 years.
Is it smarter to replace those power plants, on site, with a gas turbine plant that with produce 1/2 the CO2 at about 6.5 cents/KW. and utilize the existing transmission lines or is it smarter to build the 400,000 + turbines, at 9.3 cents/KW, on 15,000 + sq mi of land plus the cost of new transmission lines. Oh yeah, you still need to build the same gas power plants because wind operates at 30% of rated capacity (maybe you get energy today, maybe not). It’s kind of like the employee who shows up 30% of the time, can come & go as they choose, but does a great job while they are there. A luxury to have but you can’t have them as the foundation of your company.
If you want no CO2, build nuclear or hydro, but we’re demolishing them as well.

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By Bobby (Mount Kisco/NY/10549)
on August 18th, 2012

People who are celebrating must have forgotten or not be aware of a study published by Tom Wigley last year. It showed that partially replacing coal with natural gas would actually slightly accelerate climate change through 2050. And that doesn’t include methane leaks. If there were substantial leaks then the acceleration could occur until 2140. Switching involves more complexity than people realize https://www2.ucar.edu/atmosnews/news/5292/switching-coal-natural-gas-would-do-little-global-climate-study-indicates.

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By Dan Clayton (633003)
on August 19th, 2012

At least you are honest. You would do away with all combustion engines, all dary farms, all the amenities of life, on the off chance the world will not be able to handel these polutants. I understand being wise and working toward a goal, but full destruction of modern life for a theory puts you solidly on the nutty fringe.

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By Craig Curtis (Corte Madera/CA/94925)
on August 19th, 2012

It never ceases to amaze me how many who wear their scientific hats with pride, take those hats—along with the brains beneath them—off/out, by not looking at every plausible explanation that might get at what really is behind what they so lazily trot out as “global warming” (read: man-made global warming). ...

Here’s a thought for you: How about acknowledging that 90+% of what can accurately be called greenhouse gases is actually water vapor—that’s right, a gas that the sun creates when sunlight hits water, which happens to cover 70% of our planet!  What’s important about this FACT is that humans are NEVER going to be able to prevent this overwhelmingly large contribution to greenhouse gases (which, for those who don’t happen to know, are what trap infrared (i.e., heat) energy, including infrared rays of light from the sun, thereby heating our atmosphere); and yet, these useful idiots, who like to think of themselves as objective scientists, don’t have enough common sense to realize that CO2 contributions (man-made or not) only very negligibly contribute to the overall heat-trapping abilities of all greenhouse glasses!

My point is that they should acknowledge that fluctuations in the Earth’s temperature of late can be almost exclusively and accurately attributed to increased sun spot activity.  Why do they ignore such a fact?  Money, money, money….  Scientists with a leftist tendency would rather get easy money to conduct “research” from national governments—meaning taxpayers—by advancing sloppy science, than actually doing real science, which requires higher standards of scrutiny.

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By rtcdmc (Williamsport, PA 17701)
on August 20th, 2012

Ah yes, the old “nothing is as good as zero” meme.  So the U.S. declines to 1990 levels of emissions—in line with the desired targets in Kyoto—, but that’s not good enough because it wasn’t wind-generated?  This mindset usually stems from disappointment at gift-giving occasions during childhood.  Just curious, have you posted this in Chinese media anywhere?

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By M Tucker
on August 20th, 2012

Sun-spots, water vapor, “scientists promised a new ice age back in ”“ 1977 or 1968 or 1980” or what ever year you care to mention without mentioning who it was that said that and without naming the article, all thoroughly debunked by actual well respected climate scientists and atmospheric chemists and astrophysicists. I lived through that time, I studied geology at university and not a single one of my professors thought that CO2 in the atmosphere had nothing to do with warming of our planet.

It is not just Dr Hansen who I would consider a well respected expert in the field but he has been more accurate and prescient over a much longer time than anyone else I can find. Besides my university professors who introduced me to the work of Dr Charles Keeling in the early 1980’s, and who had a lasting influence on my thinking, I have found the works of Gavin Schmidt, the late Stephen Schneider, Michael Mann and Ken Caldeira, all climate scientists, very informative, and influential. Also the writing of Dr Lee R Kump, a professor of Geology at Penn State University who has written many articles as well as text books on the subject, has been enormously influential. Then there is the tireless professor and McKnight Chair Jonathan Foley at the University of Minnesota. Also all the scientists who work on the USGS PRISM project (Pliocene Research Interpretation and Synoptic Mapping) that has contributed significantly to our understanding of how the climate will respond to a CO2 concentration similar to today’s. It is not just the work of Dr Hansen. It is not something that has just come up in the past few years. The information is there for anyone interested.

This article is about US emissions but climate is responding to ALL emissions. US emissions are down due partially to an economic downturn as well as switching from coal to natural gas due primarily to market forces. But CO2 is up worldwide. Expanding reliance on coal in China and India are a large part of the reason. Continued us of fossil fuels will only lead to ever increasing amounts of atmospheric CO2 even if the entire world switched to natural gas. No break from the whipsaw climate chaos we have been experiencing for the past several years in sight. Farmers can put field tiles in place to help them drain quicker after floods. Farmers and ranchers can try to irrigate fields that are not already irrigated or to provide livestock with a dependable water supply. But it means more expensive food and I see no break from the “global weirdness” as described in Climate Central’s book.

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By Robert Shafer (Los Alamos, New Mexico 87544)
on August 20th, 2012

If the AP report included the CO2 from coal we are exporting for electricity production in other countries, perhaps the report would not show the decline. We exported over 28 million short tons of coal in the first quarter of this year (see http://www.eia.gov/coal/production/quarterly/), which I believe is about 10% of the total US production. We are shipping a lot more coal to Canada now. If we are buying back electricity from Canada (and letting them keep the CO2), it would certainly lower our CO2 output without lowering our consumption of coal-produced electricity. This is similar to California buying electricity from mine-mouth coal plants in other western states. California gets the electricity, and the rest of the states get to keep the CO2.

I believe that we are rapidly building up our CO2 exports to China now. We certainly won’t buy back their electricity, but we certainly will buy their products. See for example http://e360.yale.edu/feature/as_coal_use_declines_in_us_coal_companies_focus_on_china/2474/

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By Lewis Cleverdon
on August 21st, 2012

Michael - while I share your doubts around the hype over fossil methane as a ‘bridge’ to low GHG outputs, I’m puzzled by the idea that once we end net anthro-GHG emissions airborne CO2 ppmv would very gradually decline.

Given that we’ll have 20 to 40 years of additional time-lagged warming to endure after that ending - (until say 2080 ?),
- plus the additional warming by that date due to ending fossil sulphate outputs and so ending our maintenance of the cooling sulphate parasol (that Hansen et al put at an additional 80% to 140% of received warming),
- plus the fact that six out of seven interactive mega-feedbacks are already observed to be accelerating, and several have the potential to dwarf anthro-emissions,
why would we expect CO2 ppmv to gradually fall after 2080 ?

Specifically, given that the microbial decay of peatbogs (due to rising CO2), and permafrost melt, and forest desiccation & combustion, and global soils’ desiccation are all already outgassing CO2, and are doing so on a rising curve,
plus the effect of the other interactive mega-feedbacks’ warming that will further accelerate these CO2 sources,
it appears that in reality, in the absence of a program of Albedo Restoration to moderate global temperature and so halt the feedbacks’ acceleration, ending anthro-GHG outputs will neither end continued warming nor the continued rise of CO2 ppmv.

In this light I wonder if, on reflection, you may agree that to diminish airborne CO2 we are going to need a global program of Carbon Recovery as the necessary complement to both an equitable and efficient emissions control treaty and the requisite Albedo Restoration program ? I hope we may agree that the scientific community’s reticence on this central strategic appraisal would be taken as attempted appeasement by denialists, and could thus prove highly counterproductive.

On the other hand, if there is some reliably mitigating factor missed from the above account, I really wish you’d clarify just what it is, as I’ve yet to hear it described by any scientist.



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By mlemonick
on August 21st, 2012

It’s kind of sad to see several long-discredited myths raise their heads again here. For example, Danny says:

“We are in a warming period, due mainly to the sun being in a max cycle.”

This would be a good point if it were true. So good that solar astrophysicists have checked it out, many times. Turns out it’s false.

” I guess all those SUVs on mars, jupiter, and saturn have heated them up too.  Or is this data being ignored so foregone conclusions fit?”

This is not data, it’s myth. The only reason anyone knows the Earth is warming globally is that we have a global network of thermometers that have been taking measurements for many decades. Does anyone actually think we have anything remotely like this for any of the other planets? Seriously? Obviously we don’t, so any statement about any sort of “global warming” on any of them is not just wrong; it’s utterly ridiculous.

Craig Curtis declares:

“How about acknowledging that 90+% of what can accurately be called greenhouse gases is actually water vapor””that’s right, a gas that the sun creates when sunlight hits water, which happens to cover 70% of our planet!  What’s important about this FACT is that humans are NEVER going to be able to prevent this overwhelmingly large contribution to greenhouse gases (which, for those who don’t happen to know, are what trap infrared (i.e., heat) energy, including infrared rays of light from the sun, thereby heating our atmosphere); and yet, these useful idiots, who like to think of themselves as objective scientists, don’t have enough common sense to realize that CO2 contributions (man-made or not) only very negligibly contribute to the overall heat-trapping abilities of all greenhouse glasses!”

The word “acknowledge” suggests that someone’s trying to hide this fact. Check out our book Global Weirdness, in which we discuss water vapor quite openly. How brave of us, right? Actually, no. The people Mr. Curtis calls “useful idiots” talk about water vapor all the time. They’re objective enough to know that CO2 doesn’t cause the majority of greenhouse warming on Earth. They also know, as Mr. Curtis evidently does not, that even the small EXTRA warming from anthropogenic CO2 is enough to raise Earth’s temperature by enough to cause us big trouble.

More to come

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By Fuel microalgae (Cali, Colombia)
on August 21st, 2012

Is there any legal regulation for the use of microalgae for CO2 capture?.
Microalgae represent an opportunity for CO2 capture and recovery of nutrients from wastewater.  http://goo.gl/M8sDY

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By M Tucker
on August 21st, 2012


Your ideas and questions are.interesting to say the least. When I find a paper by an atmospheric chemist, climate scientist or geologist, perhaps glaciologist or Quaternary geologist, who addresses those issues I will give them careful consideration. I would suggest you attempt to find one of those to get a better fix on answering your questions. I enjoyed Ken Caldeira’s piece in this months Scientific American. He does go into the very long time it will take for natural processes to remove CO2 from the atmosphere. He presents a picture of what our future holds if we continue with fossil fuels until they become just too expensive to get out of the ground: hot, flooded, dead oceans, and Homo bardus (is that correct for stupid man?) fighting for space and food.

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By joe (concord/nh/03301)
on August 24th, 2012

With all the intelligence in the world, is it possible to find a way to turn CO2 into a fuel source.  2 problems solved!

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By Nicole Berger (East Hartford)
on October 24th, 2012

There is a solution to carbon dioxide emissions that can work while we use fossil fuels. Check out the link below, feel free to leave a comment. It is a good read.


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