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House of Commons Science and Technology Committee Inquiry on Public Understanding of Climate Change

The House of Commons Science and Technology Committee has launched an inquiry into Climate - Public understanding and policy implications. The terms of reference for the inquiry can be found here:

Submitted 19th April 2013

1. The Geological Society is the UK’s learned and professional body for geoscience, with more than 10,500 Fellows (members) worldwide. The Fellowship encompasses those working in industry, academia and government with a broad range of perspectives on policy-relevant science, and the Society is a leading communicator of this science to government bodies, those in education, and other non-specialist audiences.

2. We have not attempted to answer all the questions raised in the Terms of Reference for the inquiry, as most are outside the area of expertise of our Fellowship.

How could public understanding of what is meant by climate change be improved? What are the main barriers to this?

3. The science which informs public discourse on climate change tends to be dominated by a limited range of disciplinary approaches and evidence bases. There is a strong focus on atmospheric science, oceanography and predictive climate modelling, on present day observations, and on data from the recent past. The Royal Society’s September 2010 report ‘Climate Change: a summary of the science’, for instance, refers to data from the historical past, and from air bubbles trapped in ice cores up to 800,000 years old, but not to any older data. This is very recent in geological terms. The narrative of climate change which is communicated to the public by government and others is strongly shaped by this limited scientific framing, making it vulnerable to attacks on these aspects of the science base (as happened when email records at the University of East Anglia’s Climatic Research Unit were made public, for example).

4. The geological record contains abundant evidence of how the Earth’s climate has changed over hundreds of millions of years. This evidence includes direct and proxy data for ocean and atmospheric characteristics, including temperature, ocean acidity and oxygen levels, past ocean productivity, sea levels, and aspects of atmospheric composition including carbon dioxide concentrations in the atmosphere (for example from carbon isotopic analyses of marine sediments, or from analyses of fossil leaves and soils). This evidence base, and the geoscience which it underpins, is entirely independent of atmospheric modelling and data from the recent past. It shows that our climate has undergone many fluctuations over this time. On several previous occasions, including 55, 120 and 183 million years (Ma) ago, there have been rapid injections of carbon into the atmosphere, which have triggered significant changes in the climate. These included temperature increases of at least 5-6ºC globally (more near the poles) in the 55 Ma event, increased acidity and decreased oxygen levels in the oceans, increases in sea-levels and widespread species extinction. It seems likely that the source of the increased atmospheric carbon was the emission of methane from the collapse of methane hydrate deposits on the seabed, though the emission of carbon dioxide from massive emissions of lava in plateau basalts is a prominent possible alternative explanation. Such major environmental changes happened rapidly (over perhaps hundreds or a few thousands of years), but the climate took 100,000 or more years to recover. Anthropogenic emissions of carbon since 1750 amount to perhaps a quarter to a third of that released in the 55 Ma event. Moreover these recent emissions are happening very much faster – by a factor of at least ten – and will continue for several decades at least, however successful global attempts to reduce them may be.

5. Ice cores dating back as far as 800,000 years contain bubbles of trapped air from which it is now clear (as of early 2013) that carbon dioxide increased at the same time as temperature during periodic warm intervals. The rates of increase of carbon dioxide then were 10 to 100 times slower than the rate of increase over the past 100 years.

6. It is thus clear that on timescales of millions of years as well as on timescales of tens of thousands of years, carbon dioxide and temperature have changed together, and basic physics suggests that there is good reason to think that the two are connected – that is, that the rises in carbon dioxide have played an important role in driving up the temperature.

7. These various geological data allow us to calculate the climate sensitivity of the atmosphere to a doubling of CO2 independently of climate models. The fact that the climate sensitivity calculated from observed geological data matches quite well that calculated from climate models lends credibility to these climate models.

8. The Geological Society published a public statement on the climate change evidence from the deep geological record in November 2010 (see, which was prepared by a working group of geoscientists with a wide variety of relevant expertise.

9. Paying greater attention to this (independent) disciplinary approach to climate change science and evidence, and developing alternative narratives of environmental change which draw on it, has the potential to deepen public understanding of climate change, and to add resilience to efforts to build the trust of the public and engage them in efforts to reduce carbon emissions nationally and globally. It is often said, for example, that in continuing to emit carbon at current levels, we are running an unprecedented experiment on the Earth system. A more fruitful approach might be to highlight the natural analogues for this experiment that have occurred in the geological past, like the 55 Ma event. The key question to be asked is – are we now recreating conditions like those that led to the 55 Ma event?

10. There is also scope to improve engagement between climate modellers and atmospheric and ocean scientists with knowledge of evidence from the recent past, on the one hand, and geoscientists whose expertise relates to the deep geological record on the other. The design and parameters of predictive models used to forecast future scenarios, based on current observations and data from the recent past, should draw on evidence and research relating to rapid climate change events in the geological past to test and improve their performance. This kind of research is increasingly taking place and should be further encouraged.

11. Even better understanding of climate change in the past will result from greater investment in sampling the pertinent geological record – mostly that hidden either in ice cores or in deep ocean sediments where deep ocean drilling or piston coring is required to collect the materials required for analysis.

12. We would be pleased to discuss further any points raised in this submission, to provide material or suggest experts on evidence in the geological record relating to climate change, or to provide any other assistance we can as the inquiry progresses.