Climate change is not simple

I have said this before – but it bears repeating Climate change is complex. And I feel the need to repeat it now because of a current myth being pushed very strongly by climate change deniers/contrarians/sceptics. The claim that “there has been no global warming for 16 years.”

If you doubt climate change is complex have a look at this global temperature record from NASA’s Goddard Institute for Space Studies.

Fig.A2

Line plot of global mean land-ocean temperature index, 1880 to present, with the base period 1951-1980. The dotted black line is the annual mean and the solid red line is the five-year mean. The green bars show uncertainty estimates. [This is an update of Fig. 1A in Hansen et al. (2006).]

Isn’t cherry picky wonderful?

There’s a lot of noise in that graph but it does sort of support the conclusion that global temperatures have increased in the last 100 years. Mind you, if you want to create a contrary impression you can easily take a short time period – say around 1950, 1960 – 1980, 1985 – 1995 – or even the last 16 years. Cherry picking is a great thing – if your aim is to support a predetermined conclusion, and avoid (or even hide) evidence to the contrary.

So we get this sort of thing being promoted by climate change deniers (thanks to Andy for this one). Didn’t someone say a little knowledge is a dangerous thing? And isn’t cherry picking a great way of restricting knowledge?

Graph-billboard

So, just to repeat myself – here’s an extract from my post Climate change is complex. It indicates some of the scientific knowledge that climate change deniers/contrarians/sceptics ignore when they cherry pick to make this silly claims.

Natural influences just can’t explain global temperature

The figure below shows the results of simulations of global temperature from 1900 to 2005. Figure a included all the natural and anthropogenic influences.  The black line is the actual measured global temperature anomaly (obtained by subtracting the average temperature for 1901 to 1950).  The individual simulations are shown as thin yellow curves. The red line is the multi-model ensemble mean (see Figure 9.5 – AR4 WGI Chapter 9: Understanding and Attributing Climate Change).

Figure b is a similar plot using simulations which consider only the natural influences on climate. The individual simulations are shown as thin blue curves. The thick blue line is the multi-model ensemble mean.

So, climate scientist have considered both natural and anthropogenic influences. And they are unable to reproduce the global temperature changes since 1970 unless anthropogenic influences are included.

That is why the IPCC has concluded that there is a high probability (>90%) that human influences are contributing to the current observed global temperature increase.

Notice also that the experts talk about probabilities. It’s a complex field and things are rarely cut and dried. We are more certain about some influences than others. And the IPCC doesn’t hide this fact – far from it. It doesn’t make sweeping claims in the way that some of their opponents do.

Knowing what we don’t know

We can see this in another figure from the report (Figure 2.20 – AR4 WGI Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing). It shows the estimated influences of several human caused effect and solar radiation since 1750. Notice the error bars. They are much bigger in some cases than others. Notice the assessment of scientific understanding for these influences. We have a high understanding for some of them and a low understanding for others.

So, climate scientists aren’t hiding anything. They are not ignoring natural effects. They are up-front about probabilities. They acknowledge that we need more information is some areas. They are behaving like professionals.

Considering there are areas where scientific understanding is low there is clearly room for debate, discussion and more research. But deniers and contrarians who take an extreme reductionist stance, misrepresent the IPCC reports and attack honest scientists doing the research are not in a position to contribute to this.

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9 responses to “Climate change is not simple

  1. These people are idiots. But they are a vanishing minority.

    The debate is over. Superstorm Sandy, Superstorm Bopha, the Australian heat wave, the US Mid Western drought, the disappearing Northern icecap, have all made sure of that.

    The main promoters of continuing with BAU, (Business As Usual), are not the climate change deniers, but the climate change apologists, and ignorers.

    Climate change apologists are people in influential positions who when pressed will admit that climate change is a serious problem. But they will then go on to say, that jobs, the economy, growth, etc. are far more important to do anything about climate change. Such people are generally oil and coal company execs and trade union officials and conservative politicians. These people will oppose any measures that could stop, or constrain climate change. They will fight in any way, with everything they have to oppose such measures.

    The ignorers, also are people in influential positions, who also know better and when pressed will admit, that yes climate change is a problem. But, that’s it. That is all they will do. If called on to do anything, they will say that the apologists are too big and powerful and numerous to oppose, the problem is just to big, and that the public wouldn’t understand if they did speak out. But generally the ignorers will say nothing. Even through Super-storms, and Super-Heatwaves, or unprecedented droughts, these events will illicit no comment. Through out it all the ignorers will maintain their silence. The ignorers will do anything to avoid discussing climate change. Because discussing climate change, might commit them to do something about it. These people are generally, social democratic politicians aspiring for political office, and media people who don’t want to offend their sponsors.

  2. Yet how would a climate denier read this post? Inquiring minds want to know.

    (…Channels the denier thick haze of stupid…)

    So Ken, you finally admit it.
    “Climate change is complex”? Ha, wot a givaway!

    “there has been no global warming for 16 years.”
    Damn straight. Take that Mr AL BORE. You and your NASA Kommie friends.
    (Oh, let’s say “AL BORE” again just in case you missed it the first time.) Ready?
    AL BORE!

    “There’s a lot of noise in that graph”

    Which is what RESPONSIBLE, SKEPTICAL, UNCORRUPTED, PROMINENT scientists have tried to tell you religious fanatics at NASA for years!!

    “They acknowledge that we need more information is some areas.”

    Because we don’t know everything, we therefore know nothing. Stands to reason. Because we know nothing, we should do nothing.
    Works for cancer too!
    Plus Al Gore is fat.

    (…Exits the channeling. Goes off to take a long, long shower…)

  3. You realize that your first graph, the Global Land-Ocean Temperature Index, actually supports the claim the there has been almost no warming for the past 16 years, right? Even the great Pachauri had to concede that one.

    The same graph also makes me ask; so what kind of satellites were they using to measure global temperature back in 1880 anyway? Inquiring minds want to know, but alarmists like Cedric and Jenny clearly do not.

    cheers

  4. Klem, you realise that your observation is obvious and indicates you didn’t read my article. So I will repeat for you:

    “There’s a lot of noise in that graph but it does sort of support the conclusion that global temperatures have increased in the last 100 years. Mind you, if you want to create a contrary impression you can easily take a short time period – say around 1950, 1960 – 1980, 1985 – 1995 – or even the last 16 years. Cherry picking is a great thing – if your aim is to support a predetermined conclusion, and avoid (or even hide) evidence to the contrary.”

    None of those cherry picked periods support the extremely naive conclusion that the basic physical and chemical properties of greenhouse gases have suddenly disappeared.

    As for your question about temperature recording devices in 1880 – ever heard of thermometers? You know – those gadgets that met stations still use today?

  5. It’s also worth reiterating that temperature rises are not the only thing that shows more heat trapped in the atmosphere and oceans. Energy exists also in states of matter. Water contains more energy than ice even when both are at the same temperature. Water vapour contains a lot more energy than the same weight of liquid water.

  6. Poor stupid Klem

    Inquiring minds want to know, but alarmists like Cedric and Jenny clearly do not.

    Inquiring minds want to know, but alarmists like NASA etc…
    (shrug)

    http://www.giss.nasa.gov/research/news/20130115/

  7. Pingback: Extreme confirmation bias in action | Open Parachute

  8. Pingback: Extreme confirmation bias in action | Secular News Daily

  9. “Water contains more energy than ice even when both are at the same temperature. Water vapour contains a lot more energy than the same weight of liquid water.”

    I did not know that, that’s incredible. Water is truly the coolest thing on earth and almost everyone simply takes it for granted.

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