Those paying attention over the last few weeks will have noticed yet another outbreak of questioning the well-established and rigorous basis of climate science. This time, it was over the recent special report from the Intergovernmental Panel on Climate Change report on 1.5 degrees centigradeand the need for urgent action. The claims made, like always, did not stand up remotely well to scrutiny being a combination of long-debunked arguments, breathtakingly selective quotation, and mis-use of highly experimental results. But It does present an opportunity to reflect upon the lack of symmetry in process and rigour between the mainstream scientific process and that of those questioning the science. who are all too often afforded an outsized voice in the public discourse.

    It is important to state upfront that the science is robust and long-standing. We have known since the mid-19th century and the pioneering work of Eunice Foote and Carlow-born John Tyndall that various heat-trapping gases exist naturally in the atmosphere. We have known since the work of Aarhenius in 1896 that elevated carbon dioxide levels from fossil fuel burning would lead to temperature increases.

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    In the intervening years within the scientific mainstream, there have been tens of thousands of papers on myriad aspects of climate change published. We have developed ever more realistic simulations of key aspects of the climate system. We have improved observations of key climatic processes and components.

    In the last 30 years, we have seen a series of reports by the IPCC synthesise and assess the huge breadth of evidence. These reports undergo a very rigorous review process with final approval of the summary by all the governments of the world word-by-word. There is no parallel to the rigour of this process in any other scientific field and only the truly robust findings survive such stress-testing. When the IPCC reports conclude something, it really is time to stand up and take notice.

    Today, we know the climate system is changing rapidly, more rapidly than in many thousands of years. We know these changes are due to our historical actions and that they are having real-life impacts around the world. Climate change is a fact. We have developed from an agrarian culture to modern society in a period of remarkably stable climate. We are now pushing the climate system outside those bounds. There shall be consequences that we are just beginning to experience and that shall, undoubtedly, get worse.

    We should not be debating whether climate change exists, in the same manner as we don’t seriously debate whether gravity exists

    Given all of the above, why do those wishing to spread doubt persist? Primarily because the solutions to climate change, unlike the ozone hole, require wholesale changes in our lifestyles. We have become uniquely dependent upon fossil fuels to service our current lifestyles. Just think of all the ways you use fossil fuels from transport, through home heating, electricity and to source the food you eat. There is, therefore, a willing audience for bad faith actors to spread confusion and doubt.

    There are a myriad of approaches taken by those wishing to spread doubt including:

    (1) the pantomime gambit. "There is some cabal of scientists who control the science". This falls apart when it becomes obvious there are many thousands of practicing experts all of whom undertake analysis and peer review. No small cohort can hold sway for multiple decades. Anyone who has ever been to a science conference would see an analogy to a sack of cats. It would make any one of those scientist’s careers to disprove climate change. That they haven’t says all you need to know.

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    (2) the bad data gambit. This involves finding a station or timeseries that isn’t well sited, contains a large adjustment or any number of other criticisms in a similar vein. This approach disintegrates upon a consideration that the observational evidence arises from many thousands of lines of evidence. For all climate indicators, multiple groups have exhaustively analysed the data and come to the same broad conclusion. It further collapses when a consideration of coherency across indicators as diverse as sea-ice, surface temperature, humidity, growing season etc are considered. That would require a staggeringly implausible level of commonality of residual errors coherent in space and time.

    (3) the bad models gambit – Because simulations are based upon models which are incomplete representations of complex reality, the argument goes, they can’t be trusted. We use imperfect models all the time in many aspects of our daily lives unthinkingly. Very few of these have been tested to the extent climate simulations have. Climate simulations have been repeatedly shown to reproduce historical changes and important processes. We’ve had these complex models long-enough to use new observations to test early models. Comparisons of what they projected to what we see today are in good concordance. Newer models are better still.

    (4) the alternative hypothesis – Some alternative process exists, a hitherto unrecognised long-term climate oscillation or a climate system mechanism. To be taken seriously and to overturn the accepted science would require the formation and testing of a hypothesis that could better explain what we are observing. To put it as politely as possible, this is highly implausible. The physical processes are very well established and have been repeatedly stress-tested. 

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    It is important to recognise that those spreading misinformation are not limited to those advocating that the problem does not exist or is nothing to worry about. There is also a strain of climate catastrophism which is just as dangerous. Climate is an incredibly serious problem to address, but scenarios such as The Day After Tomorrow are just as absurd as those arising from the other end of the spectrum. It is the measured assessments of the IPCC and national learned bodies such as the NAS or the Royal Society that we should be paying heed to.
    The time has come for us to recognise that we have a serious challenge on our hands in climate change. We should not be debating whether it exists, in the same manner as we don’t seriously debate whether gravity exists. It is a fact. What we should be debating is what we can do to address the challenge. Let us hope we are turning the corner to do just that.

    This article was first published on RTE Brainstorm on 22nd Jan 2019