Humans Cause Global Warming: 10 Indicators

Humans_Cause_Global Warming

10 key indicators of a human fingerprint on climate change below, with links to the science behind them.

The science is firm that global warming is happening. Even so-called “climate skeptics” are realizing this. We have discussed many times on Planetsave how humans cause global warming and the main effects and causes of global warming, but with so many people still confused or unaware, when someone comes out with an excellent visual AND science-backed explanation of how human actions are causing global warming, it is a crime not to share.

–> Highly recommended: What is Causing Global Warming?

Global warming expert John Cook of Skeptical Science has just done that. A recent post of his, 10 Indicators of a Human Fingerprint on Climate Change, is where I got the visual above. To go with that visual, here are 10 science-backed explanations of those 10 indicators:

  1. Humans are currently emitting around 30 billion tonnes of CO2 into the atmosphere every year (CDIAC). Of course, it could be coincidence that CO2 levels are rising so sharply at the same time so let’s look at more evidence that we’re responsible for the rise in CO2 levels.
  2. When we measure the type of carbon accumulating in the atmosphere, we observe more of the type of carbon that comes from fossil fuels (Manning 2006).
  3. This is corroborated by measurements of oxygen in the atmosphere. Oxygen levels are falling in line with the amount of carbon dioxide rising, just as you’d expect from fossil fuel burning which takes oxygen out of the air to create carbon dioxide (Manning 2006).
  4. Further independent evidence that humans are raising CO2 levels comes from measurements of carbon found in coral records going back several centuries. These find a recent sharp rise in the type of carbon that comes from fossil fuels (Pelejero 2005).
  5. So we know humans are raising CO2 levels. What’s the effect? Satellites measure less heat escaping out to space, at the particular wavelengths that CO2 absorbs heat, thus finding “direct experimental evidence for a significant increase in the Earth’s greenhouse effect”. (Harries 2001Griggs 2004Chen 2007).
  6. If less heat is escaping to space, where is it going? Back to the Earth’s surface. Surface measurements confirm this, observing more downward infrared radiation (Philipona 2004,Wang 2009). A closer look at the downward radiation finds more heat returning at CO2 wavelengths, leading to the conclusion that “this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming.” (Evans 2006).
  7. If an increased greenhouse effect is causing global warming, we should see certain patterns in the warming. For example, the planet should warm faster at night than during the day. This is indeed being observed (Braganza 2004Alexander 2006).
  8. Another distinctive pattern of greenhouse warming is cooling in the upper atmosphere, otherwise known as the stratosphere. This is exactly what’s happening (Jones 2003).
  9. With the lower atmosphere (the troposphere) warming and the upper atmosphere (the stratosphere) cooling, another consequence is the boundary between the troposphere and stratosphere, otherwise known as the tropopause, should rise as a consequence of greenhouse warming. This has been observed (Santer 2003).
  10. An even higher layer of the atmosphere, the ionosphere, is expected to cool and contract in response to greenhouse warming. This has been observed by satellites (Laštovi?ka 2006).

The science on this matter is clear, and with regards to science and climate change science, Cook summarizes things so well here again that I think it’s pointless to do anything but repost his summary comments:

Science isn’t a house of cards, ready to topple if you remove one line of evidence. Instead, it’s like a jigsaw puzzle. As the body of evidence builds, we get a clearer picture of what’s driving our climate. We now have many lines of evidence all pointing to a single, consistent answer – the main driver of global warming is rising carbon dioxide levels from our fossil fuel burning.

There it is. Along with his 119 one-liners for disputing a climate denier’s claims, here is another great summary of the topics and the scientific conclusions.

Image Credit: John Cook/Skeptical Science

About the Author

is the director of CleanTechnica, the most popular cleantech-focused website in the world, and Planetsave, a world-leading green and science news site. He has been covering green news of various sorts since 2008, and he has been especially focused on solar energy, electric vehicles, and wind energy since 2009.

Aside from his work on CleanTechnica and Planetsave, he’s the founder and director of Solar Love, EV Obsession, and Bikocity.

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  • Caba Aba Baba

    “this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming.” (Evans 2006).

    is CO2 the only factor in the amount of heat being released? There’s a logical leap there.

    Besides, that’s not an experiment, it’s an observation.

  • Caba Aba Baba

    “this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming.” (Evans 2006).

    is CO2 the only factor in the amount of heat being released? There’s a logical leap there.

    Besides, that’s not an experiment, it’s an observation.

  • Fuck-off

    Zachary is retarded…

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  • In the past decade, CO2 is up 30% yet there has been no change in average world temperature…
    The science is too shaky to be trying to impact the economy and peoples’ lives till we are more certain.

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  • Adada

    Zachary, I notice that you only hold a B.A. in environmental studies and sociology and that you are not a climatologist. I would say from the fact that you are not a climatologist that you are not suitably qualified or experienced to state that global warming is being caused by mankind. 

    Furthermore, volcanic activity over the last few years around the world has created more greenhouse gases that man has made since the industrial revolution.

    Speak to any volcanologist or climatologist that isn’t being given bribes by the worlds governments!

  • Adada

    Zachary, I notice that you only hold a B.A. in environmental studies and sociology and that you are not a climatologist. I would say from the fact that you are not a climatologist that you are not suitably qualified or experienced to state that global warming is being caused by mankind. 

    Furthermore, volcanic activity over the last few years around the world has created more greenhouse gases that man has made since the industrial revolution.

    Speak to any volcanologist or climatologist that isn’t being given bribes by the worlds governments!

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  • Michael

    population growth is the main issue, but no-one is talking about it, at least not publicly.
    more humans, more food production, and of course, more transportation needs, industrial production, etc. make your case about population growth control, if you can. unfortunately, I don’t think the some (or all) of the religious beliefs will listen to you. there are dozens of UN countries that subscribe to the notion that every family should have 20 + children, and the western world need to: (1) feed them, (2) heal their diseases, (3) educate them, (4) fight their internal conflicts, etc., and they are only responsible to breed.

    • perhaps that is because the footprint of a U.S. citizen is about 25 times that of the people you are talking about.

      plus, no one has said this is not an issue.

      BUT our responsibility in the matter is cutting our out-of-this-world consumption and emissions.

  • MajorTom

    First we had man-made global cooling, then warming, then climate change, now back to warming.
    Seems to me like nothing more than yet another way to demonize productive industrialized civilizations. To scare the public with man-made Armageddon. After all, isn’t it us fat lazy Americans who are stealing food from starving children all over the planet because of our vehicle preferences? Possibly because we like electricity, and use it for everything! Give me a break!

    The earth is getting a tad warmer, so what! It really makes me wonder what these climate quacks are going to be doing in 10-20 (or even 100+) or so years when it may begin to start cooling again. Can ANYONE deny that data from 1800 on is FAR to narrow of a data set to even begin to attribute the warming to man?

    I remember when the CO2 in ice core samples was “proof” that CO2 was part of the reason it was getting warmer. Then it was found that these levels trailed behind the temperature by some 100 or so years. Now it is claimed to have a “feed-back loop” effect with the temperature. Amazing how conclusions keep changing to prove we are killing the planet.

    Nut-job, power hungry, hateful people are the ones funding this “science” (I’m looking at you Mr Gore). Imagine being a scientist, needing a purpose (and a job) got a huge grant to find out how humans are causing global warming. What would happen to potential future funding if your findings did not fit the agenda of your funders? And this agenda is obvious, money, power, and control.

    • your claims about the back and forth on global warming & cooling are wildly off target:

      & sorry, but you must not understand the consequences of global warming at all. it’s not a slight inconvenience. it’s severe




      (the lack of food & water that result, and that kill people)

      and new diseases

      it’s also considered a huge national security concern:

      you claims are all obviously pulled from denier websites that cherry pick and misrepresent like it’s their fossil-fuel-funded job.

      i also love how you have no trust or faith in thousands upon thousands of climate scientists. did you go to university?

      for more, please see all the scientists NOT studying climate change who have examined and backed up the climatologists work:

      255 Leading Scientists, 11 Nobel Laureates Write Letter Supporting Climate Scientists & Climate Science ( )

      17 Nobel Laureates Call for “fundamental transformation and innovation in all spheres and at all scales in order to stop and reverse global environmental change” ( )

      BEST Study (Climate Science Skeptic Study) Finds Global Warming is Real — Global Warming Deniers Are Pissed (What’s New?) ( )

      Note: these organizations say global warming caused by humans is a FACT:

      U.S. Agency for International Development
      United States Department of Agriculture
      National Oceanic & Atmospheric Administration
      National Institute of Standards and Technology
      United States Department of Defense
      United States Department of Energy
      National Institutes of Health
      United States Department of State
      United States Department of Transportation
      U.S. Geological Survey
      U.S. Environmental Protection Agency
      University Corporation for Atmospheric Research
      National Center for Atmospheric Research
      National Aeronautics & Space Administration
      National Science Foundation
      Smithsonian Institution
      International Arctic Science Committee
      Arctic Council
      African Academy of Sciences
      Australian Academy of Sciences
      Royal Flemish Academy of Belgium for Sciences and the Arts
      Academia Brasileira de Ciéncias
      Cameroon Academy of Sciences
      Royal Society of Canada
      Caribbean Academy of Sciences
      Chinese Academy of Sciences
      Académie des Sciences, France
      Ghana Academy of Arts and Sciences
      Deutsche Akademie der Naturforscher Leopoldina of Germany
      Indonesian Academy of Sciences
      Royal Irish Academy
      Accademia nazionale delle scienze of Italy
      Indian National Science Academy
      Science Council of Japan
      Kenya National Academy of Sciences
      Madagascar’s National Academy of Arts, Letters and Sciences
      Academy of Sciences Malaysia
      Academia Mexicana de Ciencias
      Nigerian Academy of Sciences
      Royal Society of New Zealand
      Polish Academy of Sciences
      Russian Academy of Sciences
      l’Académie des Sciences et Techniques du Sénégal
      Academy of Science of South Africa
      Sudan Academy of Sciences
      Royal Swedish Academy of Sciences
      Tanzania Academy of Sciences
      Turkish Academy of Sciences
      Uganda National Academy of Sciences
      The Royal Society of the United Kingdom
      National Academy of Sciences, United States
      Zambia Academy of Sciences
      Zimbabwe Academy of Science
      American Academy of Pediatrics
      American Association for the Advancement of Science
      American Association of Wildlife Veterinarians
      American Astronomical Society
      American Chemical Society
      American College of Preventive Medicine
      American Geophysical Union
      American Institute of Physics
      American Medical Association
      American Meteorological Society
      American Physical Society
      American Public Health Association
      American Quaternary Association
      American Institute of Biological Sciences
      American Society of Agronomy
      American Society for Microbiology
      American Society of Plant Biologists
      American Statistical Association
      Association of Ecosystem Research Centers
      Botanical Society of America
      Crop Science Society of America
      Ecological Society of America
      Federation of American Scientists
      Geological Society of America
      National Association of Geoscience Teachers
      Natural Science Collections Alliance
      Organization of Biological Field Stations
      Society of American Foresters
      Society for Industrial and Applied Mathematics
      Society of Systematic Biologists
      Soil Science Society of America
      Australian Coral Reef Society
      Australian Medical Association
      Australian Meteorological and Oceanographic Society
      Engineers Australia
      Federation of Australian Scientific and Technological Societies
      Geological Society of Australia
      British Antarctic Survey
      Institute of Biology, UK
      Royal Meteorological Society, UK
      Canadian Foundation for Climate and Atmospheric Sciences
      Canadian Meteorological and Oceanographic Society
      European Federation of Geologists
      European Geosciences Union
      European Physical Society
      European Science Foundation
      International Association for Great Lakes Research
      International Union for Quaternary Research
      International Union of Geodesy and Geophysics
      Intergovernmental Panel on Climate Change
      World Federation of Public Health Associations
      World Health Organization
      World Meteorological Organization

  • you rock man

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  • If all humans are concerned about is their carbon footprint and CO2 levels, and not the vast array of other chemicals, gasses and pollution in the atmosphere which we create, indirectly, by supporting certain industries and businesses, then we are blind to the real threat of our atmospheric chemical soup. There are many less conspicuous but far more dangerous chemicals and gasses being pumped into the atmosphere, some of which hold far more heat than CO2, and combined they pose a much bigger risk, causing climate change and extreme weather events which make global warming seem like the understated tip of the iceberg.

    How long will our atmosphere protect and nurture us if it is becoming unstable and prone to more extreme climate change, even on a daily basis? If we continue to destroy ecosystems, forests and vegetation on a global scale, Oxygen levels will be reduced and plants will not absorb CO2 or other de-stabilizing toxins in the air and soil. Climate control vegetation is one sure way to bring the atmosphere and biosphere back into a more harmonious state. Further destruction of the Plant Kingdom and pursuit of polluting technology will surely lead to an even more serious global warming catastrophe.

    REGREEN THE URBAN/DESERT PLANET….with a Global Paradise Quest at CoolGlobe.Net

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  • Why is everybody ignoring the ice core studies that PROVE that CO2 moves as a result of natural climate variation? If AGW theory was correct, this would be impossible.
    AGW is simply a wealth transfer rationale by socialists who hate capitalism.

    • @Roger — yes, CO2 is affected by natural climate variation AND it affects climate. it is called a feedback loop and is accounted for in the science. it is one simple piece of the puzzle.

  • For the past ten years I have been investigating the climate controversy. I have a PhD in chemical physics and out of curiosity thought it would be worthwhile to look at both sides of the issue. Initially I assumed that the facts presented by the AGW supporters were unbiased and grounded in good science. I however was naturally suspicious that computer codes predictions had any credibility, much less the 90% accuracy as stated by the IPCC, because of my experience with code writing and analysis. I also studied the ozone hole phenomenon some years ago including the chemical kinetics and data sets collected over time. With respect to the Ozone hole, which is complicated but much less so then AGW, my conclusion was it was real and our response of banning CFCs warranted. However, the data sets for the Mann’s Hockey Stick are, at best, unreliable and most likely cherry picked to support AGW. A very readable and honest review which I carefully examined can be found at You should read it even though it was written by a skeptic.

    Even more important is the revelation which is slowly becoming known as Satellitegate, which from a scientific standpoint, should dwarf Climategate. Google it. It seems that the satellite temperature data that has been used in every AGW code is highly suspect and dead wrong in many cases. The predictions of those codes cannot be believed with and degree of certainty at this point. NOAA is slowly admitting this fact, and is now taking some of the satellites offline and not disseminating the data around the world. NOAA charges users for this data and I believe will be sued because it has known this fact for some time. The revelation of Satellitegate seems to have been broken by an insider. So far as I can find out there are, at this time, five satellites involved. Indeed, it is likely that there is not enough historically reliable data to even show that the earth has been warming over the past decade, much less that any warming might be caused by the anthropogenic increase in CO2 since the industrial revolution.

    • JTK

      Your claims are false. Climategate was overblown nonsense that had no controversy to it at all. No data was altered. Nothing happened in the minds of rational people, only cranks fell for it. Your claims about the satellite data are similarly bogus. I’m not sure what conspiracy theorist website you heard those lies on but they are flat out false. Shame on you for not seeing right through them.

  • So you publish a list of what most educated people on both sides of the question already agree to and claim that it proves something. The climate has gotten warmer and colder for billions of years. CO2 levels have been much higher with temperatures about the same, ice ages have come and gone without help from human produced CO2.

    You have nothing to say about natural variation in climate, and how much of recent warming is attributable to CO2. Temperatures were warmer than today a thousand years ago, and CO2 was much less. Where is your paper explaining how and why that happened? Or are you quoting the discredited Hockey Team scientists that it wasn’t warmer then? Same was true at least a couple of more times since the last ice age. Inconvenient truths don’t get much time on AGW kook aid sites.

    • the hockey stick graph and the science around it have been supported by independent review numerous times now. inconvenient as that may be to you.

    • Wow. what a bunch of global warming denying morons. I taught skiing on glaciers 10,000 years old that disappeared in just 15 years. 500,000 square miles of Chilean glacial fields dried up in 5 years, after scientists thought it would take another hundred years of climate change to occur. Your ignorance and playing with the facts and believing any b.s. that comes your way so you can keep driving your Hummer is suicidal and selfish. What a bunch of human pigs.