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The global warming 'pause' is more politics than science

Posted on 8 April 2015 by dana1981

The so-called 'pause' in the rate of global warming is false and distracting. It is a politically engineered excuse to avoid taking action on climate change.

Over the past 17 years, the Earth has warmed rapidly, accumulating energy at a rate equivalent to more than four atomic bomb detonations per second. That's over 2 billion atomic bombs worth of heat built up on our planet since 1998.

As discussed in a new book by one of us (Dana Nuccitelli) Climatology versus Pseudoscience, research has shown that much of the heat buildup during that time was deposited in the deep layers of the Earth's oceans, temporarily keeping it from the surface.

A new article co-authored by the other of us (Michael Mann), shows that natural ocean oscillations have recently acted to temporarily slow the warming of the Earth's surface temperatures, in combination with a relatively quiet sun, and active volcanoes.

Despite this temporary masking of some of the surface warming, 2005, 2010, and 2014 each set records for global surface temperature, and 2015 is thus far on pace to break the record once again. Such is the profound nature of human-caused global warming, that it has overcome these many short-term natural cooling influences.

Yet a purported global warming 'pause' (more aptly named the 'faux pause') is often used as an excuse by those who oppose taking action to curb climate change. For example, Republican Senator and US presidential candidate Ted Cruz recently said on American TV:

"Many of the alarmists on global warming, they've got a problem because the science doesn't back them up. In particular, satellite data demonstrate for the last 17 years, there's been zero warming."

This assertion is problematic for several reasons. First of all, it is wrong: the satellite data clearly show ongoing warming over the past two decades.

Secondly, the satellite data in question only estimate the temperature of the atmosphere above Earth's surface. We, and most other living things, reside on Earth's surface, and the data tell us that surface warming continues unabated.

Finally, warming of the atmosphere accounts for only about two per cent of overall global warming; more than 90 per cent goes into heating of the surface and the oceans. That heating contributes to the melting of the ice sheets, and the acceleration of global sea level rise.

The faux pause has nonetheless been used by political partisans like Senator Cruz to cast doubt on the overwhelming scientific consensus that humans are causing rapid global warming, simply because they find the political implications of that scientific reality inconvenient — to their ideological views and the views of the special interests who fund their campaigns.

This is especially troubling given that climate change poses a variety of significant risks to Earth's species, including humans, and the best way to mitigate those risks is to reduce our reliance on the fossil fuels that are causing them. However, there are powerful vested interests pressuring governments to instead maintain the fossil fuel status quo.

For example, in the short-term, Australia and its coal industry benefit economically by exporting coal to developing nations. While the US, UK, and France have tried to cut export subsidies for coal stations in third world countries and instead shift support toward low-carbon energy sources, the Abbott government has opposed those moves. It has has also asked Bjorn Lomborg to help launch the Australian Department of Foreign Affairs and Trade's development innovation hub, which is intended to "find better ways to help poorer countries."

Lomborg has argued that the faux pause implies "that the real challenge of global warming has been exaggerated". He is expected to suggest that developing nations should view climate change as a low priority. 

The unfortunate reality is that third world countries tend to be the most vulnerable to the impacts of climate change. Lomborg's rosy outlook on climate change, which is largely based on the faux pause, conveniently supports the Australian government's preference for maintaining its coal export status quo.

Click here to read the rest

Dana Nuccitelli is an environmental scientist and climate blogger for Skeptical Science and The Guardian. He is author of the recent book "Climatology versus Pseudoscience: Exposing the Failed Predictions of Global Warming Skeptics".

Michael E. Mann is Distinguished Professor of Meteorology at Penn State University. He is author of the book "The Hockey Stick and the Climate Wars".

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Comments 1 to 19:

  1. Recommended supplemental reading:

    Global warming hiatus explained and it's not good news by Graham Readfearn, ABC Environment, Apr 8, 2015

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  2. @ John Hartz The comments are at least as illuminating :)

    Another here, a repost from The Conversation, the comments are more illuminating than the article.

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    Moderator Response:

    [JH] Link activated.

  3. In many ways having heat energy stored in the oceans is even worse than in the atmosphere. First of all, it is "out of sight, out of mind" making it harder to get political policy changes to reduce emissions. But another problem is that it stores the heat for much longer. Heat in the atmosphere has a chance to radiate away into space, but in the oceans it is trapped for a very long time so we can expect centuries of trouble. It also contributes to sea level rise by the expansion of water. Then that warmer water works its way under and around the floating and grounded ice shelves such as those in the West Antarctic, greatly increasing the chances that they will go unstable much sooner than they would otherwise.

    So no, the fact that the oceans are taking the heat and we don't experience so much of it where we live is not a good thing.

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  4. Dana, I understand that your trademark is to be in the vanguard og the AGW movement, but if you are hoping that we will read your stuff, please be more precise, otherwise its too easy for sceptics to write you off as an uninformed propaganda source. Your monthly global Lower Troposphere v5.6 Anomaly that you link to does indeed show that there has been warming over the last two decades (1995 to 2015), but it also shows that there has been no significant warming over the last 17 years (1998 to 2015) - so the statement is in fact accurate, and your point completely invalid.

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    Moderator Response:

    [DB] "there has been no significant warming over the last 17 years (1998 to 2015)"

    Please provide a citation for this claim.

  5. MartinG wrote: "...but it also shows that there has been no significant warming over the last 17 years (1998 to 2015) - so the statement is in fact accurate, and your point completely invalid."

    There has been no statistically significant warming of the global lower atmosphere in the past five minutes.

    That statement is true. However, it is not a 'valid' argument. The '17 years' statement, if the appropriate qualifiers (e.g. 'statistically significant' & 'lower atmosphere') were included, would also be true, but invalid for exactly the same reasons. If you can't understand the difference you should probably read Dana's article again.

    Any statistician who is not a complete fraud will tell you that if shifting the end points a few units radically changes the trend then you are looking at too small an interval to establish a valid trend. Whether that interval is 17 years or 5 minutes doesn't matter... you're basing conclusions on a mathematically meaningless result.

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  6. Why are people so concerned about the last 17 years? It seems like a rather odd time frame, compared to say, decades, or 5 years increments, or a moving average of some sort. Are they concerned about the possible effect of climate change on the cicadas? When I look at the average global temperature anomalies for each decade I don't see anything like a pause.

    1970's: 0.067, 0,026 higher than the 60's

    1980's: 0.231, 0.164 higher than the 70's

    1990's: 0.394, 0.163 higher than the 80's

    2000's: 0.594, 0.170 higher than the 90's

    (All data from NASA)

    I'm pretty sure than when we get to 2020, the 2010's decade will show a similar increase in global average temperature anomaly.

    They aren't picking a 17 year time frame because they are just cherry picking convenient dates that appear to support their claims, right?

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  7. Oops, the 2000's were 0.564, 0.170 higher than the 90's. Typo.

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  8. @6, it is non-incompetent propaganda admitting that industrial upheaval(aka "a period of consolidation") is underway: the long expected resource bottlenecks are being exploited as we speak!

     Basically blue-chip shares are working out how to stay blue-chip shares... delay delay delay!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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    Moderator Response:

    [RH] Please tone it down.

  9. MatinG is looking at a "trend" starting from the whopper El-Nino year of 1998, and of course the trend is lower starting that year. How about the warming from 1999 Martin? Or from 1997? Or 1996? The fake skeptics have literally done this for years now. What's really happening is, as years that are on par with 1998 pile up in the absence of El-ninos, we see the new normal: year after year near or above 1998 temperature in spite of numerous cooling influences, especially a sun delivering less irradiance than back then.

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  10. PhilippeChantreau,

    Of course you are correct.

    The comment policies here prevent me from saying what I really think, but I wonder if climate scientists and reasonable people everywhere have been too tolerant of this nonsense. I accept that some people are truly stupid enough to fall for the "since-1998" line, and I see that there is a need to provide outreach education to those who are genuinely confused, but I suspect that true confusion on the issue is relativey rare. I do not believe the "since-1998" line can be promoted in good faith by people capable of forming a paragraph of reasonable-sounding prose that includes the words "significance" and "trend". There can be no reasonable grounds for making an argument based on the lack of significance of a trend from that obviously outlying year, and only cynicism, cognitive dissonance or a reckless desire to score cheap debating points divorced from scientific reality can explain how commonly the argument is aired.

    I cannot think of a single case where someone has raised the "since-1998" line, stayed around long enough to get educated, and subsequently made a useful contribution to the "debate". To me it is almost invariably a marker of bad faith, and I know as soon as a poster raises it that I am unlikely to see them follow it up with anything worthwhile.

    I have been wondering if Climate Science needs its own version of Godwin's Law, where the first person to raise the "since-1998" nonsense can be declared the loser without further discussion. I know that would raise its own problems, and we need some way for the genuinely confused to be pointed in the right direction, but it is painful to see the discussion dragged down to this level so regularly.



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  11. I'm thinking whatever "pause" there may be in surface temperatures will be going away very soon...

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  12. It seems that Mother Nature has been trying pretty hard to slow down the warming, but the last 12 months has still been the warmest on record with an anomaly of +0.71oC.

    Global temp last 25 years

    The March anomaly from GISS will probably push the running 12-month mean up to at least +0.72°C, one more step into record territory.
    And if the present weak El Niño strengthens and last for the rest of the year, the temperature anomaly for 2015 may well end up between +0.75°C and +0.8°C.

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  13. To piggy-back onto PhilippeChantreau's and Leto's comments, the "skeptic" focus on ("but what about since 1998!") becomes understandable: when evidence, the physics of our world and Mother Nature itself is against you, misdirection is the only ploy left in the ideological gameplan:

    Click on me for bigger version

    Click on me for bigger version

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  14. Daniel Bailey @13, I think you are being a little unfair.  The fake skeptics also like looking at the blue wedge of the pie graph in the upper right of the second image (but never, of course, at the red sections of that graph).

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  15. Yes, pie is tasty.  AIUI, the fake-skeptics prefer cherry above all other flavours.


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  16. To top up the pile of arguments rebuting MartinG's claim, it's worth noting that UAH temp set Martin bases his claim on, is not only inaccurate, plagued my many biases and corrections (we are talking v5.6 here, how many more corrections/versions are we going to see in the future?), but above all UAH temp set is about lower troposphere temperature.

    But we are not living in the troposphere, so who cares about it? We are living at the surface, so the GW at the surface is the one we should be concerned about.

    Further, radiative models predict that atmospheric warming in response to GHG increase is not uniform: strongest at the surface, decreasing as the hight increases, and finally as you reach the stratosphere, the effect becomes opposite: lower stratosphere is actually cooling! That effect is confirmed by all 3 data sets from UAH. Trying to cherrypick one of those (TLT set) to argue the "GW has paused since 1998" is just pathetic ignorance. With proper understanding of science, one can clearly see that any TLT set is expected to show smaller warming than any surface temperature set. Not to mention high inaccuracy of UAH sets. So, even longer than usual time interval in this set is needed to confidently say anything about its trends.

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  17. Here's my analysis based on an LSQ fit to an RSS graph I saw on WUWT site (unclear to me whether they were saying it was Monckton or Knappenberger-Michaels LSQ fit):

    1996/10-2014/10 = 0.0 degrees/century (18 years 1 mo. = 217 months)

    WUWT Monckton(?) LSQ fit with comment <I paraphrase> exactly zero warming.

    1999/02-2014/10 = 1.2 degrees/ century (15 years 9 mo. = 189 months)

    *more recent* my well-estimated eyeballed fit *on the very same WUWT graph* for this later period.

    Thus, Monckton (I think it is) shows clearly that "global warming" increased just 16 years ago.
    Not only that but the fun part now: 1.2 degrees later warming trend / 0.0 degree earlier warming trend = infinity so the Monckton (?) analysis *shows an infinite increase of "global warming" just 16 years ago*.

    I'm like that other bunch, Monckton and that, I hugely prefer fun & games to actual work.


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  18. Slighly OT I suspect, but (long term reader, first comment) I just received email from skeptic friend in response to a piece he read on NOAA Tropsphere data. Why does it start around 1980 on most charts. WHat happens if you go back further? He claims it shows no warming. I suspect it is just  amatter of different methods, but dont remember it being directly addressed here. Thanks.


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  19. steve222 @18, the temperatues series start in late 1978 because that was when the first satellite used for the data started operation (later for the TUT channel).  

    There are two key tricks with the satellite data.  First, the TMT data (and hence the TLT) data which is derived from that channel, draws a significant amount of its temperature information from the lower stratosphere, which is cooling.  So much so that the TLS channel shows a trend of -0.259 K per decade to the end of 2015.

    The second is that the satellite data shows an exagerated (and delayed) response to ENSO events, and volcanoes relative to surface temperature data.  When viewing the full record, that makes the noise and hence the standard error large when calculating trends.  When truncating the data to start from 1997 as deniers often do, it gives a false indication of no trend where in fact a trend actually exists.

    For what it is worth, the NOAA TMT trend to the end of 2015 is 0.123 K/decade, which is far from flat.  The TLT trend would be larger.


    One further nuance worth noting is that the weighting function above is actually calculated for the US Standard Atmosphere.  The actual atmospheric weights observed will vary depending on altitude of the land surface, and latitude.  The later is because convection carries the air mass much higher in the tropics, which lifts the peak weight of the weighting function to a higher altitude.  That is why for Fu and Johansson's TTT channel (and artificial channel determined by a linear composition of TMT and TLS data), they use different weights for the TMT and TLS channels for global average, and tropical data.  The practical effect is that satellites do not measure the temperatures of the same altitude band of the atmosphere at different locations across the globe.

    As warming of the air causes the height of the atmosphere to increase, it will also change the weighting function.  That is, a positive temperature trend in the troposphere will result in the satellites using data from progressively higher (and hence cooler) sections of the atmosphere.  I know that this effect is not compensated for in the various satellite temperature products.  I do not know that it is a significant effect.  That is, its effect on trends may well be only -0.00001C/decade or less for all I know.  Worse, increasing CO2 warms the troposphere (causing it to rise) but cools the stratosphere (causing it to shrink) thereby increasing the stratospheric contamination of the TMT channel over time.  Again, I have no idea of the magnitude of this effect.  I just mention these possibilities to highlight that it is far from straight forward to assume the various satellite temperature products represent a reliable record of tropospheric temperatures.

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