Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Twitter Facebook YouTube Mastodon MeWe

RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

New? Register here
Forgot your password?

Latest Posts


Can we fix global warming?

What the science says...

Select a level... Basic Intermediate Advanced
The argument that solving the global warming problem by reducing human greenhouse gas emissions is "too hard" generally stems from the belief that (i) our technology is not sufficiently advanced to achieve significant emissions reductions, and/or (ii) that doing so would cripple the global economy. However, studies have determined that current technology is sufficient to reduce greenhouse gas emissions the necessary amount, and that we can do so without significant impact on the economy.

Climate Myth...

It's too hard

"The fact is that there is no one in the world who can explain how we could cut our emissions by four fifths without shutting down virtually all our existing economy. What carries this even further into the higher realms of lunacy is that such a Quixotic gesture would do nothing to halt the world’s fast-rising CO2 emissions, already up 40 per cent since 1990. There is no way for us to prevent the world’s CO2 emissions from doubling by 2100" (Christopher Booker)


Pacala and Socolow (2004) (PS04) investigated our capability to reduce greenhouse gas (GHG) emissions by examining the various technologies available to reduce GHG emissions.  Every technology they examined "has passed beyond the laboratory bench and demonstration project; many are already implemented somewhere at full industrial scale."  PS04 examined what would be required to stabilize atmospheric carbon dioxide concentrations at 500 parts per million (ppm), which would require that GHG emissions be held near the present level of 7 billion tons of carbon per year (GtC/year) for the next 50 years. 

PS04 used the concept of a "stabilization wedge", in which "a wedge represents an activity that reduces emissions to the atmosphere that starts at zero today and increases linearly until it accounts for 1 GtC/year of reduced carbon emissions in 50 years."  Implementing seven such wedges would achieve sufficient GHG emissions reductions to stabilize atmospheric carbon dioxide at 500 ppm by 2050, and emissions would have to decrease linearly during the second half of the 21st century.  PS04 identifies 15 current options which could be scaled up to produce at least one wedge, and note that their list is not exhaustive.

  1. Improved fuel economy: One wedge would be achieved if, instead of averaging 30 miles per gallon (mpg) on conventional fuel, cars in 2054 averaged 60 mpg, with fuel type and distance traveled unchanged.  Given recent advances in hybrid and electric vehicle technology, this is a very plausible wedge.

  2. Reduced reliance on cars: One wedge would be achieved if the average fuel economy of the 2 billion 2054 cars were 30 mpg, but the annual distance traveled were 5000 miles instead of 10,000 miles.

  3. More efficient buildings: One wedge is the difference between pursuing and not pursuing known and established approaches to energy-efficient space heating and cooling, water heating, lighting, and refrigeration in residential and commercial buildings.

  4. Improved power plant efficiency: One wedge would be created if twice today’s quantity of coal-based electricity in 2054 were produced at 60% instead of 40% efficiency.

  5. Substituting natural gas for coal: One wedge would be achieved by displacing 1400 gigawatts (GW) of baseload coal power with baseload gas by 2054.  Given recent natural gas price decreases, this is another very plausible wedge.

  6. Storage of carbon captured in power plants: One wedge would be provided by the installation of carbon capture and storage (CCS) at 800 GW of baseload coal plants by 2054 or 1600 GW of baseload natural gas plants.

  7. Storage of carbon captured in hydrogen plants: The hydrogen resulting from precombustion capture of CO2 can be sent offsite to displace the consumption of conventional fuels rather than being consumed onsite to produce electricity.  One wedge would require the installation of CCS, by 2054, at coal plants producing 250 million tons of hydrogen per year (MtH2/year), or at natural gas plants producing 500 MtH2/year.

  8. Storage of carbon captured in synthetic fuels plants: Large-scale production of synthetic fuels from carbon is a possibility.  One wedge would be the difference between capturing and venting the CO2 from coal synthetic fuels plants producing 30 million barrels of synthetic fuels per day.

  9. Nuclear power: One wedge of nuclear electricity would displace 700 GW of efficient baseload coal capacity in 2054. This would require 700 GW of nuclear power with the same 90% capacity factor assumed for the coal plants, or about twice the nuclear capacity currently deployed.

    Wind power: One wedge of wind electricity would require the deployment of 2000 GW of nominal peak capacity (GWp) that displaces coal electricity in 2054 (or 2 million 1-MWp wind turbines).  This would require approximately 10 times the current (as of 2010) deployment of wind power by mid-century.  Note that global wind power deployment increased from approximately 40 GW in 2004 to 158 GW in 2009.

  10. Solar photovoltaic power: One wedge from photovoltaic (PV) electricity would require 2000 GWp of installed capacity that displaces coal electricity in 2054.  This would require approximately 100 times the current (as of 2010) deployment of solar PV power by mid-century.  Note that global solar PV power deployment increased from approximately 3 GW in 2004 to 20 GW in 2009.

  11. Renewable hydrogen: Renewable electricity can produce carbon-free hydrogen for vehicle fuel by the electrolysis of water. The hydrogen produced by 4 million 1-MWp windmills in 2054, if used in high-efficiency fuel-cell cars, would achieve a wedge of displaced gasoline or diesel fuel.  However, use of renewable energy to power electric vehicles is more efficient than powering hydrogen vehicles with hydrogen produced through electrolysis from renewable power.

  12. Biofuels: One wedge of biofuel would be achieved by the production of about 34 million barrels per day of ethanol in 2054 that could displace gasoline, provided the ethanol itself were fossil-carbon free. This ethanol production rate would be about 50 times larger than today’s global production rate, almost all of which can be attributed to Brazilian sugarcane and United States corn.  The potential exists for increased biofuels production to compromise agriculturaly production, unless the biofuels are created from a non-food crop or other source such as algae oil.

  13. Forest management: At least one wedge would be available from reduced tropical deforestation and the management of temperate and tropical forests. At least one half-wedge would be created if the current rate of clear-cutting of primary tropical forest were reduced to zero over 50 years instead of being halved. A second half-wedge would be created by reforesting or afforesting approximately 250 million hectares in the tropics or 400 million hectares in the temperate zone (current areas of tropical and temperate forests are 1500 and 700 million hectares, respectively). A third half-wedge would be created by establishing approximately 300 million hectares of plantations on non-forested land.

  14. Agricultural soils management: When forest or natural grassland is converted to cropland, up to one-half of the soil carbon is lost, primarily because annual tilling increases the rate of decomposition by aerating undecomposed organic matter.  One-half to one wedge could be stored by extending conservation tillage to all cropland, accompanied by a verification program that enforces the adoption of soil conservation practices that work as advertised.

PS04 concludes "None of the options is a pipe dream or an unproven idea....Every one of these options is already implemented at an industrial scale and could be scaled up further over 50 years to provide at least one wedge."  While the study has identified 15 possible wedges, PS04 argues that only seven would be necessary to stabilize atmospheric CO2 at 500 ppm by mid-century.  The list in the study is also not exhaustive, for example omitting concentrated solar thermal power and other renewable energy technologies besides wind and solar PV.

However, Dr. Joseph Romm (Acting Assistant Secretary of Energy for Energy Efficiency and Renewable Energy during the Clinton Administration) argues that at least 14 wedges would be necessary to stabilize atmospheric CO2 at 450 ppm.  Romm proposes what he believes to be the most plausible way to achieve 16 wedges:

  • 1 wedge of vehicle efficiency — all cars 60 mpg, with no increase in miles traveled per vehicle.
  • 1 of wind for power — one million large (2 MWp) wind turbines
  • 1 of wind for vehicles –another 2000 GW wind. Most cars must be plug-in hybrids or pure electric vehicles.
  • 3 of concentrated solar thermal power — ~5000 GW peak.
  • 3 of efficiency — one each for buildings, industry, and cogeneration/heat-recovery for a total of 15 to 20 million GW-hrs.
  • 1 of coal with carbon capture and storage — 800 GW of coal with CCS
  • 1 of nuclear power — 700 GW plus 10 Yucca mountains for storage
  • 1 of solar PV — 2000 GW peak [or less PV and some geothermal, tidal, and ocean thermal]
  • 1 of cellulosic biofuels — using one-sixth of the world’s cropland [or less land if yields significantly increase or algae-to-biofuels proves commercial at large scale].
  • 2 of forestry — End all tropical deforestation. Plant new trees over an area the size of the continental U.S.
  • 1 of soils — Apply no-till farming to all existing croplands.

The bottom line is that while achieving the necessary GHG emissions reductions and stabilization wedges will be difficult, it is possible.  And there are many solutions and combinations of wedges to choose from.


Working Group III of the IPCC Fourth Assessment Report focused on climate change mitigation, and a substantial portion of the report focused on the economic impacts of mitigation efforts.  The key finding of the report is as follows.

"Both bottom-up and top-down studies indicate that there is substantial economic potential for the mitigation of global GHG emissions over the coming decades, that could offset the projected growth of global emissions or reduce emissions below current levels (high agreement, much evidence)."

The report found that stabilizing between 445 and 535 ppm CO2-equivalent (350–440 ppm CO2) will slow the average annual global GDP growth rate by less than 0.12%.  Additionally, this slowed GDP growth rate is in comparison to the unrealistic business-as-usual (BAU) scenario where climate change has no impact on the economy.  By 2030, the IPCC found that global GDP would decrease by a total of no more than 3% compared to the unrealistic BAU scenario, depending on the magnitude of the emissions reductions. 

The report also found that health benefits from reduced air pollution as a result of actions to reduce GHG emissions can be substantial and may offset a substantial fraction of mitigation costs.  Some other key findings:

"Energy efficiency options for new and existing buildings could considerably reduce CO2 emissions with net economic benefit."

"Forest-related mitigation activities can considerably reduce emissions from sources and increase CO2 removals by sinks at low costs"

"Policies that provide a real or implicit price of carbon could create incentives for producers and consumers to significantly invest in low-GHG products, technologies and processes. Such policies could include economic instruments, government funding and regulation"

In short, there are numerous opportunities to reduce GHG emissions at low cost, some of which result in a net economic gain.  Overall, emissions can be reduced at a cost which will not cripple the global economy.  Moreover, these emissions reductions would have a significant positive economic impact by slowing global warming.

We have the necessary technology.  The net costs to implement them will not be crippling.  The question remains - do we have the will to put forth the effort and initial investment to solve the problem?

Last updated on 15 November 2010 by dana1981.

Printable Version  |  Offline PDF Version  |  Link to this page

Argument Feedback

Please use this form to let us know about suggested updates to this rebuttal.


1  2  3  Next

Comments 1 to 25 out of 73:

  1. I would be interested to see some update of this rebuttal to take into account the growing belief that we need to get down to 350ppm CO2 (or even 350ppm CO2e) to prevent dangerous climate change. thanks.
    Response: [JC] This issue is addressed in Why it's urgent we act now on climate change.
  2. I'm all for a carbon tax but how do we stop companies from trying to protect their profit margins by passing the burden of the tax on to the consumer or by sacking their workers? My guess would be that if we had more government run businesses, who were on board with looking after the public interest, they could undercut the prices of the privately owned companies if they tried to pass the burden of the carbon tax on to the consumer, thus ensuring that the majority of the carbon tax would come out of their profit, as it should.
  3. Continuing reply to Gilles' comment here. "This knowledge is not difficult to get." I asked how you knew that reducing fossil fuel use more destructive to hundreds of millions of people than global warming; you provided the above retort with a link to the World Bank's page on China's rural development. The linked page does not mention fossil fuels at all; rather, it speaks of changing land use policy, agricultural modernization and natural resource management. In addition, note this: Bank-funded projects have also increased forest plantation areas by hundreds of thousands of hectares, and improved the State Forestry Administration’s and provincial forest bureaus’ capacity to plan, develop, manage and protect forest resources. Planning is also underway for China’s first use of bio-carbon funds sequestering carbon through forest plantations ... -- emphasis added The reference you provide thus demonstrates an instance of exactly the sort of action you feel is unnecessary. So your point remains unsubstantiated; your argument weakened by your own evidence. Once again illustrating the poverty of the denialist position, wherein all arguments devolve to some variant of 'I think' or 'Everyone knows' or 'No, its not.'
  4. Muoncounter : if you really think that the influence of fossil fuel consumption on the standard of living is less obvious than that of the average temperature, I'm afraid I can't argue further with you. We are obviously not living on the same planet.
  5. Gilles: According to this Wiki page almost all European countries and Hong Kong produce about 25% of the CO2 per capita as the USA. My observation is that their living standards are about the same as the USA. Can you provide data to support your extraordinary claim of standard of living depending on fossil fuel consumption, or would you rather continue to assert this claim without data? Obviously it is possible to live well with 25% of USA emissions, Europe is doing it now. You have provided little or no data to support your claims. Why should I believe your hand waving?
  6. Gilles, "if you really think that the influence of fossil fuel consumption on the standard of living is less obvious... " I most certainly did not say that; I simply said that your attempt at substantiating your point failed dismally. It would be far more beneficial for the conversation at large if you tempered your opinions with actual facts. That is really what this website is all about. Facts can be discussed and evaluated; opinions just hang in the breeze.
  7. It's a bit of misdirection at work. What makes for a high standard of living is not ready access to fossil fuels. It's ready access to energy. If that energy just happens to come from, say, solar / wind / hydro / nuclear / biofuel sources, then, well, what do you know, the standard of living is still the same! I also agree with michael sweet's comment at #5: many developed economies are running quite nicely with far lower carbon intensity that the US or Australia. But, no, it's all about "I've got a right to drive the kids to school in a two-and-a-half-tonne SUV that gets 12 miles to the gallon!" The low-hanging fruit is definitely points 1 and 3 in the article above. The cost is minimal, but the savings in terms of energy are quite substantial! By "minimal cost", I really do mean minimal, e.g. with far stricter fuel efficiency requirements on new vehicles, total fuel consumption would drop significantly as older vehicles were replaced. What would the cost be? Approximately zero, financially, but certainly a lot of complaining from people who like to drive huge cars with thirsty engines... What about better insulation of buildings? Well, there are plenty of case studies pointing out that this is a net positive over the longer term, as you generally make back more than the cost of the insulation in terms of lower energy bills. This is only going to become more so as electricity and gas prices continue to rise.
  8. "Gilles: According to this Wiki page almost all European countries and Hong Kong produce about 25% of the CO2 per capita as the USA. My observation is that their living standards are about the same as the USA" according to meteorological data people in Hong Kong live in a average temperature of 23 °C ( 73 °F) but in New York city, it's only 12 °C (55°F). So I conclude that temperature has also no effect on the standard of living. Please use the SAME methodology to compare the influence of FF and the influence of GW - the discussion will be more scientific. bern : "It's a bit of misdirection at work.What makes for a high standard of living is not ready access to fossil fuels. It's ready access to energy." no, it is access to cheap and convenient energy and all energies are not equivalent. Carbon is used to reduce chemically oxides, for instance, much cheaper than electricity. oil is a liquid - much more convenient for transportation. the other point of my argumentation is persistently ignored : even if you raise the EFFICIENCY of the use of FF (diminish the energy intensity), there is no way to prevent people from offsetting this efficiency by an INCREASE in the numbers of goods - for instance more EV would produce MORE CO2 than few thermal engines - and yes, there is plenty of potential demand for a western life of style - just 5 billions of people are more or less excluded from this way of life, and they will be 8 or 9 in 50 years. And there is no moral justification - or even practical possibility to let them eventually use all FF we have spared - for CO2, it won't matter WHO has produced it !
  9. Mucounter : if you want data, you can go to the excellent site gapminder now you can choose for x-axis : CO2 production per capita (log scale) and for y-axis : any wealth indicator you want (GDP, life expectancy, literacy, and so on...) unfortunately they don't have "average temperature" in their data - so I can't check the influence of average temperature on the living standard.
  10. Giles@8 It may (or may not) be true that "temperature has no effect on the standard of living", but either way it misses the point that the major problem with climate change is the change. Our civilizations, and especially our agricultural practices, are optimised to the particular climate in which they have developed. Any change in our way of life and especially our agricultural practices, will involve adaption, which has a cost. Us in the first world (that are primarily responsible for the problem) can cope with this adaption without great suffering as we have the resources; the same is not the case for the third world, where they don't have the resources to adapt, and where argriculture is often quite marginal to begin with. The relationship between temperature and standard of living is a red herring.
  11. Haha, of course we could fix global warming. Technically. The thing is, we could technically also fix poverty, starvation and aids. In this case, what really matters, isn't what the climate science says, but what the social sciences say.
  12. batvette "Most humans make their livelihood engaged in one form of human industrial activity or another. Telling people they have to stop living, and it really is that brutally simple, to save the earth... how do you think they'll take that?" Just read the advanced version of this post. You'll notice that it requires quite a bit of ' industrial activity' to achieve the aims. We don't have to stop living, we have to change the way we do things - mostly the same things. We do not have to don sackcloth and live in caves gnawing on uncooked tubers. We can live in carbon neutral homes and work in carbon neutral businesses producing carbon neutral goods or services. With any luck some of those 'neutral' activities will actually be carbon negative - a great boon. What's 'not living' about a properly insulated home serviced by solar PV and an electric powered car- which handily acts as a battery for a distributed power grid? Sure we should be less wasteful with food and no-one needs 100 pairs of shoes nor houses the current size built in Australia. The advertising industry need not die either, they just advertise quality and improved products and lifestyle rather than foolish acquisition of more and more pointless stuff. This 'telling people they have to stop living' silliness is the very worst kind of alarmism.
  13. Sorry I omitted this. batvette's full comment can be found over at "Climategate conspiracy"
  14. As a european who lived in the US for a while, this is one of the first things I noticed, the way they use energy and resources in general. In a few words, they just don't care, they use them as if they are infinite and cheap. Europe is just a bit better, or less bad if you wish. Still, we consume about half as the average american. Then, if by "stop living" batvette means "stop living the way we do", i.e. wasting huge amounts of energy and resources, I agree. I dare to ask americans in first place, but not just them of course, to stop wasting, a first easy and reasonable step. We're heading to the open ocean with not enough fuel and food supplies, it's not going to be safe nor pleasant.
  15. We should probably wave goodbye to Ray Anderson of Interface, who passed away recently. I'm not exactly pro-capitalist, but Ray's story is uplifting anyway. His death is rather the opposite.
  16. There are no silver bullets, there is no one solution that will mitigate all CO2 and/or heat effects but there are several solutions for 1/4 to 1/3 of the problem like soil sequestration, CCS, carbon tax and rebate, alternatives, and yet-to-be-designed ways to pump heat to the upper atmosphere (I'm an engineer so that's generally how I would approach it). Some of these policies imply a need for cap and trade, but that may be mitigated by the fact that we subsidize traditional farming already and would change that to techniques like this:
  17. Sphaerica, your comment here points out that a single solution can't solve the entire problem. But as I point out above, there are no silver bullets, we will need lots of solutions. Your comment about it being much easier to burn the fossil fuels than capturing the emissions is very valid. Your tree growing example that I linked above points out that difficulty using photosynthesis as the primary solution. But we will undoubtedly have technology for that as well, it's only a matter of time. Nano-Engineered Bioconstructs Perform Photosynthesis Faster Than Nature Does
  18. 17, Eric, Certainly, agreed, multiple incremental solutions will be needed. My point in the redwood analogy is to demonstrate the scope of the problem. That's what I'm afraid you don't appreciate. You're waving future technology like a magic wand that will make everything just go away in the nick of time, when I don't think the technology will ever exist to restore the balance. The problem is quite simply too large for that. We have spent a hundred years running uncounted millions of motors, small to large, that create energy by burning carbon and emitting CO2. The reverse process will at best require uncounted millions of filters, running for a hundred years, using energy from some unknown source simply to extract CO2 from the atmosphere and somehow sequester it so it can't get out again. I just don't see it happening. Ever.
  19. The technology to sequester will be there, just a modest amount of government research funding and extensive cross-fertilization from commercial technology (e.g. nano-tech) will make it happen. What we will lack is the economics to perform the sequestering on a large scale anything close to the scale of the automobile and other fossil fuel burners. For that reason I don't see it happening either. But I do see a variety of things happening that will all add up. If, for example, we can build a space elevator or something like that, we can also build large chimneys to suck excess heat into space. The updrafts created in the chimney would provide alternative energy. That's just one idea off the top of my head.
  20. 19, Eric (skeptic), You are fooling yourself. No chance. None.
  21. I think if the feedbacks played nice we'd more or less get away with this slowly coalescing slipshod approach to tackling climate change that we've seen over the past 25 yrs. If going to +2-2.5 triggers a substantial methane release or the collapse of the amazon basin we may find ourselves up fifth street without a camel.
  22. michael sweet, I appreciate your feedback in the other threads on ocean warning and developing economies. The developing economies do not need to build cars nor completely convert their economies from agriculture, but they can move a step up from subsistence agriculture and add considerable robustness to environmental catastrophe. Thailand is a good example of bouncing back after their floods. Industry can also include business process outsourcing that is non-energy-intensive. CATO published a well-balanced article pointing out some of the drawbacks and benefits to globalization. One drawback is rising wage inequality (that may be a persistent feature of capitalism). The main benefit is economic robustness which helps to tackle present and future problems including problems resulting from warming, especially in developing countries.
  23. Eric: the CATO Institute is a right wing canned research foundation owned by the Koch brothers. You need to start citing peer reviewed articles, not Koch propaganda. I can see why you are so uninformed about so many different subjects. As far as developing economies (which are OT on this thread), if there is widespread drought caused by AGW there will be widespread disruption and starvation. Try to find some reliable sources to refer to instead of canned research.
  24. I work with green action groups. In my mind, there are pervasive forms of denial common amongst such groups that almost approach the level of dangerous attitude as in those who deny global warming;

    1. Acting locally (My friends and I all have sustainable homes, we eat locally, we recycle, and drive hybrids) will be enough.  Not even close to being right. What about folks living in high rises in Chicago in the wintertime?

    2. The  Hubbard's Peak driven scarcity of fossil fuels will force reform. Old fashioned point of view. We  now know we have enough readily available fossil fuels to fry the planet.

  25. @Chris,

    It depends upon how a carbon tax is done. First, it needs to be universal, so all carbon energy inputs are taxed, including fertilizer, biofuels, ethanol, plastics manufacturing, and imports from overseas containing carbon. Second, the proceeds of the tax need to be refunded. The tax proposed by Professor James Hansen and submitted as legislation in the last session of Congress by Representative Pete Stark of California would refund all of the collected carbon tax to households using the same mechanism that was used to issue stimulus checks during the financial crisis of 2007-2008. The refund would be per-person listed on federal income tax returns in the household. 

    This would put a price on carbon wherever it came into the United States economy, and then, since, as you say, companies would pass the costs on to people, it would refund these costs to them in proportion to the average use of carbon.  If a household reduced its overall consumption of carbon by simply buying the cheaper products in the new carbon-penalized marketplace, not only would their purchases be offset, they could earn money from the deal.

    I don't like cap-and-trade.  I think it gives companies too much wiggle room to cheat. 

    The point of the carbon tax is to internalize the actual costs of carbon consumption in prices on the street. So, sure, gasoline would go up in price, concrete would go up in price, food grown with oil-sourced fertilizer would go up in price, and those silly plastic bottles of water would go up in price because the plastic they are packaged in would be taxed.  But competing products which did not use these sources would not go up in price.  People would buy more economical cars because they  would be cheaper to drive. And they would probably buy less overall, build less (wood would go up in price, too), and generally consume less.

    The marketplace would figure the relative disincentive into its workings, and would be stimulated to produce carbon-free or minimal carbon products to get people to buy them.  The transition would probably be pretty quick, and would be easier because most carbon taxes are introduced over a period of time.

    Food prices are going to go up a lot because of climate change.  Insurance premiums are going to go up.  And companies are eventually going to have to shut down during summers in places because they simply cannot operate. 


1  2  3  Next

Post a Comment

Political, off-topic or ad hominem comments will be deleted. Comments Policy...

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

Link to this page

The Consensus Project Website


(free to republish)

© Copyright 2023 John Cook
Home | Translations | About Us | Privacy | Contact Us