Global warming or climate change?


When I saw the cartoon below, I recalled that there have been times when I too was gently chastised for using the phrase ‘global warming’ and told that it was outdated and that the correct term was ‘climate change’. I was a little puzzled by this for two reasons. One is that I was unaware that there was some kind of shifting standard to be followed regarding usage. The other is that I felt that they referred to two different things so one could not replace the other.

Wiley-global warming

Global warming is pretty specific and quantifiable and refers to the fact that average global temperature has been increasing with time. On the other hand, I always saw climate change as less well-defined (because climate is not as well-defined as temperature) but a consequence of global warming, and referred to the frequency shifts of major weather patterns with more extreme ones occurring more frequently.

The website Skeptical Science says that my sense that these two phrases were referring to two different things is justified.

Thus while the physical phenomena are causally related, they are not the same thing. Human greenhouse gas emissions are causing global warming, which in turn is causing climate change. However, because the terms are causally related, they are often used interchangeably in normal daily communications.

The argument “they changed the name” suggests that the term ‘global warming’ was previously the norm, and the widespread use of the term ‘climate change’ is now. However, this is simply untrue. For example, a seminal climate science work is Gilbert Plass’ 1956 study ‘The Carbon Dioxide Theory of Climatic Change’ (which coincidentally estimated the climate sensitivity to a doubling of atmospheric carbon dioxide at 3.6°C, not far off from today’s widely accepted most likely value of 3°C). Barrett and Gast published a letter in Science in 1971 entitled simply ‘Climate Change’. The journal ‘Climatic Change’ was created in 1977 (and is still published today). The IPCC was formed in 1988, and of course the ‘CC’ is ‘climate change’, not ‘global warming’. There are many, many other examples of the use of the term ‘climate change’ many decades ago. There is nothing new whatsoever about the usage of the term.

So both terms are correct and current and need to be used in the appropriate contexts.

Interestingly, it appears that Republican pollster and strategist Frank Luntz, who has made a career out of using focus groups to identify the best language to frame political issues to favor conservative causes, was someone who urged Republicans to adopt the phrase ‘climate change’ because it sounded less scary than ‘global warming’. He said this in a leaked memo where he suggested ways to steer people’s concern over the environment away from proposals that might hurt his clients, saying (p. 142):

“Climate change” is less frightening than “global warming”. As one focus group participant noted, climate change “sounds like you’re going from Pittsburgh to Fort Lauderdale.” While global warming has catastrophic connotations attached to it, climate change suggests a more controllable and less emotional challenge.

Incidentally the Luntz memo’s section on global warming and climate change (p. 137-142) provides a fascinating insight into how these operators try to manipulate public opinion on this important issue.

Comments

  1. Henry Gale says

    I always thought that ‘climate change’ was being used instead of ‘global warming’ because talking about global warming when the outside temperature is below zero could lead to some incredulous comments.

  2. Rob Grigjanis says

    ahcuah: Unfortunately, those who can’t tell apples from oranges, or arses from elbows, will always be with us.

  3. Dan Pangburn says

    Forcings (per unit area) have units Watts i.e. Joules/sec. To produce energy change (Joules), the forcing must exist for a time period. Temperature change is energy change divided by effective thermal capacitance. Thus a scale factor times the time-integral of the forcing produces the temperature change.

    CO2 has been considered to be a forcing. Because, during the previous glaciations and inter-glacials, the CO2 level and temperature went up and down nearly together, the energy change is obviously not a result of a scale factor times the time integral of the CO2 level. This observation actually proves that CO2 has no significant effect on temperature at least up to about 280 ppmv.

    This same type assessment over the entire Phanerozoic demonstrates that ‘climate sensitivity’ (the average global temperature increase caused by a doubling of the CO2 level to 580 ppmv from the pre-industrial level of 280 ppmv) is not significantly different from zero.

    The two natural factors that do explain average global temperature since before 1900 (including the flat since before 2001) with 95% correlation are disclosed in Energy and Environment, vol. 25, No. 8, 1455-1471.

  4. guthriestewart says

    Just in case anyone is wondering, Dan’s post, #4, is horribly wrong. The climate sensitivity is reckoned to have a mean about 3.2 C, perhaps as low as 2 or as high as 4.5 or so, but these are much less likely.

    Co2 is a forcing because it is, it is a greenhouse gas and all the nonsense Dan can come up with doesn’t affect that.

  5. Rob Grigjanis says

    Dan @4:

    This observation actually proves that…

    It doesn’t prove anything except that past warmings involved other factors. To say that therefore CO2 cannot be a forcing is bad logic as well as bad science. See here.

  6. Crimson Clupeidae says

    I’m trying to figure out how the denialist @4 thinks that saying the C)2 and temperatures have a strong correlation ‘obviously’ means they aren’t related…..

    Does he think we can’t actually read the words? That’s in addition to his moderately sciencey sounding gibberish being flat out wrong from what I can see.

  7. moarscienceplz says

    Stress that you are seeking a “fair balance” between the environment and the economy.

    There’s no right-wing echo chamber, no siree! Nothing to see here.

  8. Kilian Hekhuis says

    “Global warming is pretty specific and quantifiable and refers to the fact that average global temperature has been increasing with time. On the other hand, I always saw climate change as less well-defined” – I think metereologists can define climate pretty well, albeit that the warming (or cooling) part is just one of many variables. As Wikipedia puts it, “Climate is a measure of the average pattern of variation in temperature, humidity, atmospheric pressure, wind, precipitation, atmospheric particle count and other meteorological variables in a given region over long periods of time.” And there you also have another difference between global warming and climate change: global warming is, well, global, while climate change is more local, part of a specific “region”. You can’t talk about the global climate. Of course, the average ‘murican couldn’t care less about the rest of the world, but even the US has a number of different climates.

  9. Lassi Hippeläinen says

    The terms are not interchangeable. ‘Global warming’ only goes up. ‘Climate change’ covers also cases when temperature goes down, like in recent history (in geological sense) when the ice ages arrived. Global warming is a subset of climate change.

    As you can see, I disagree about Wikipedia’s claim that ‘climate’ is locally limited. I’ve seen it used in a global sense, even without the ‘global’ attribute.

  10. sailor1031 says

    Those who took Climatology or Geography will know that there are climate types – Mediterranean, Maritime, Continental, Polar etc. These types are not global.
    Those who took Physics will recall that Svante Arrhenius demonstrated that a doubling of CO2 results in a temperature increase of about 1.6 degrees C. That in a closed system with no heat transported away by convection. The idea that climate sensitivity is in the 3 – 4.5 degreeC range rests on two things. A reliance on unvalidated computer models that don’t even reproduce the past, let alone accurately predict the future, and a hypothetical, but unproven, “multiplier effect” that CO2 supposedly has on other GHGs particularly water vapour. If this effect was actually proven we wouldn’t have a range of sensitivities to pick from would we?
    Dan @4 is more right than most of the rest of you. If you think he’s wrong then show how with evidence. It’s no argument to say merely “shutup you ‘denialist’, you’re wrong” without saying how/why.

  11. guthriestewart says

    Comment #11 is a more sophisticated type of denialist screed. Reference to unverified computer models, for instance. What a verified computer model would look like is left as an exercise for the reader.
    Moreover, the models are actually set up using past information, or indeed run backwards, and give accurate enough replicas that they can be trusted as much as such models can be. Stating things that are known to be wrong could be seen as a form of lying.
    As for water vapour, it does increase with increasing temperature, which oddly enough is what CO2 causes. More info here:
    http://www.skepticalscience.com/Climate-change-Water-vapor-makes-for-a-wet-argument.html
    http://www.nasa.gov/topics/earth/features/vapor_warming.html

    The range of sensitivities is in part due to the horrible complexity of the earth systems and other factors which I don’t know much about. Expecting a perfect answer with complete certainty indicates a lack of scientific knowledge and of how the world works.

    Finally, I note that the denialist demands that we prove Dan wrong, yet makes a number of statements in their post that have no supporting evidence apparent. Such is the denialist lifestyle, demanding that other people do the work to educate them, rather than going and making use of the many freely available information sources to find out about climatology.

  12. Nick Gotts says

    Because, during the previous glaciations and inter-glacials, the CO2 level and temperature went up and down nearly together, the energy change is obviously not a result of a scale factor times the time integral of the CO2 level. – Dan Pangburn@4

    All this demonstrates is your lack of understanding. Of course temperature is not “a result of a scale factor times the time integral of the CO2 level”, and no climate scientist has ever claimed it is, AFAIK. The effect of an increase in greenhouse gas levels is to trap more heat, but that doesn’t mean it will keep getting hotter indefinitely, which is what that claim would imply. Rather, a new, but higher equilibrium temperature is reached. BTW, for anyone who doesn’t know, Energy and Environment is the denialists’ home “journal”, which prints as much egregious rubbish as any creationist publication. Oh, and temperatures have not been flat since before 2001.

    The idea that climate sensitivity is in the 3 – 4.5 degreeC range rests on two things. A reliance on unvalidated computer models that don’t even reproduce the past, let alone accurately predict the future, and a hypothetical, but unproven, “multiplier effect” that CO2 supposedly has on other GHGs particularly water vapour. – sailor1031

    Complete tosh. The computer models used are not “unvalidated”, nor does the estimate of climate sensitivity rest primarily on them, but on empirical data<, both recent and paleoclimatic. As for the “unproven multiplier effect”, it’s a consequence of some fairly basic physics: warmer air holds more water vapour.

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