The IPCC report - is the science settled?

Thursday 3 October 2013, 15:44

Paul Hudson Paul Hudson

Last week the Intergovernmental panel on climate change (IPCC) issued their latest high profile report on the current understanding of climate change.


Their main conclusion is that there can be little doubt that man is responsible for at least half of the rise in global temperatures since the 1950s, due to man-made greenhouse gases.


As a geophysicist myself, I cannot argue with the science behind the greenhouse effect, which is based on sound physical principles.  


To that end, the science behind how greenhouse gases such as carbon dioxide would cause warming of the atmosphere, in my mind, is settled.


But there are areas of the science which cannot be described as anywhere near settled, where there are uncertainties that cannot be easily dismissed.


These uncertainties have been an area that I have focused on over the last few years on this climate blog.


The one area which is perhaps as crucial as any is that of climate model performance, because governments around the world are using climate projections to make long term planning decisions, in particular on future energy generation.


Judge for yourself if this part of the science is settled, from the IPCC report, Section D1: 


‘The observed reduction in surface warming over period 1998-2012 is due roughly in equal measure to a reduced trend in radiative forcing and cooling from internal variability, which includes a possible redistribution of heat within the ocean (medium confidence).’


‘There is low confidence in quantifying the role of changes in radiative forcing in causing the reduced warming trend.'


‘There may also be a contribution from forcing inadequacies and, in some models, an overestimate of the response to increase greenhouse gas and other anthropogenic forcing.’


To highlight this area of uncertainty further, in late 2009, I wrote an article which you can read HERE in which I look at the then apparent slowdown in global warming.


In it, I discuss research from the Met Office Hadley Centre.


In the research the authors discuss why they believe a levelling off of temperatures can be expected at times.


The research shows that near zero temperature trends for intervals of a decade or less can be expected due to the model’s internal climate variability.


But crucially, the research rules out zero (temperature) trends for intervals of 15 years or more.


We are now 15 years into the so called ‘pause’ in global temperatures and the research further illustrates that this crucial part of climate science is far from settled, and it’s disappointing that more time wasn’t given to this issue across the media in the days since the report was published.


That said the authors of this report are in little doubt that over the longer term, man is altering our climate by adding greenhouse gases to the atmosphere.


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    Comment number 1.


    as you must know the IPCC process is predominantly a political process. Politically, it was important that the message to policy makers was one of 'greater confidence'. The reality, however, is that the science is still in its infancy and there is a lot more unknown than known. Against that background the only surprise is that anyone believes that it is possible to model the climate. So, please keep pointing out the many failures of the climate alarmists. In the end it will turn out that you were right to do so.

  • rate this

    Comment number 2.

    So pleased that I am not the only one who thinks the science is NOT settled! I always think it is so ironic the stance the BBC takes and at the same time championing Darwin who was very science against the 'establishment' at the time! Perhaps the BBC should be renamed - the GBC (g=government!)

  • rate this

    Comment number 3.

    1) If their main conclusion is that there can be little doubt that man is responsible for at least half of the rise in global temperatures since the 1950s, due to man-made greenhouse gases, what do they think caused the other half?

    2) How come the science is 'settled' when anyone argues the case against AGW - but there's 'much more research needed,' when the grant money's running out?

    3) What would the authors of the report be doing, if they weren't working for the IPCC?

  • rate this

    Comment number 4.

    "The IPCC report - is the science settled?"

    The science is never 'settled' (otherwise it wouldn't be science); but in the case of AGW, it's fair to say that the science is pretty well 'established'.

    By the by, UAH just posted +0.37C for September 2013; the joint third warmest September in its record. This makes 2013 (to date: Jan-Sep) currently the joint 5th warmest year on the UAH record. From the daily AMSU updates, it looks as though October has already started out on a very high temperature footing globally.

    ENSO conditions remain firmly neutral.

  • rate this

    Comment number 5.

    newdwr54 - only the 3rd Oct. I think he's been reading your complaints about how long he takes to publishes 'warm' or 'cold' months!


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Hello, I’m Paul Hudson, weather presenter and climate correspondent for BBC Look North in Yorkshire and Lincolnshire. 

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I worked as a forecaster with the Met Office for nearly 15 years locally and at the international unit, after graduating with first class honours in Geophysics and Planetary physics at the University of Newcastle upon Tyne in 1992. I then joined the BBC in October 2007, where I divide my time between forecasting and reporting on stories about climate change and its implications for people's everyday lives.

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