- Appendix 4 -
Further considerations
Climate science & policy beyond 2013

- Reproduced from Climate Change: Biological & Human Aspects 2nd edition (2013) -


With this book’s first edition (2007) Cambridge University Press kindly afforded a couple of pages as Appendix 4 to allow a brief summary of the IPCC’s 2007 assessment (AR4) at the book’s final page-proof stage: that assessment literally came out a couple of months before this book’s first edition was published. This time the IPCC’s 2013 assessment (AR5) will come out several months after this edition sees light of day and so I now use this appendix in a different way.

In the course of lectures and encounters following this book’s first edition I have invariably been asked a number of questions as to my personal thoughts, as opposed to recounting the climate science and policy developments. Other than commenting on likely prospective research and policy analysis avenues, in the main I have shied away from answering, especially as most people have expected me to be predictive: what will happen to such and such in coming decades? And of course nobody can predict the future. Having said that, I do have some personal thoughts on climate science and policy. Given that there has been interest in my own take beyond that of appraising the literature, I now make a couple of points in this short appendix, quite separate from the main body of the text: I do not wish to contaminate my earlier (hopefully) sober review of the science and policy with wilder personal musings.

First, on the policy front, I feel sincerely that there is a pressing need for the way nations account for fossil carbon emissions to be more rigorous. It is not just that international aviation and shipping emissions are excluded, but the problem of economic carbon leakage between nations. The way the figures are currently calculated purely relate to a nation’s in situ greenhouse gas emissions. To take the UK as an example, carbon dioxide equivalent (CO2-eq) greenhouse gas emissions have – according to the way they are currently calculated – been in decline since 1991–2 to the present (2011 being the last full year of data at the time of writing). Yet the UK imports manufactured goods and also imports very roughly half its food. Fossil energy and fertiliser (part fossil-based) are used to provide these. Of course, some of this currently unaccounted fossil carbon will be offset by UK exports, but only a proportion: the UK is by far a net importer of unaccounted carbon. When looking at UK emissions, and those of other individual nations, what is needed are additional metrics to take this carbon leakage into account. Nations need to know how much greenhouse gas emission their citizens are causing through their ‘total net emissions’; that is, imports less exports. Of course, care needs to be taken to avoid double accounting but the bottom line is that a further metric still is needed: the net total fossil carbon used to generate a pound (or dollar), which is effectively total net emissions divided by GDP. This is a measure of the economy’s fossil carbon efficiency.

Some may say that additional metrics will make life too complex. This is a specious counter argument. We are already used to multiple metrics for many commonly reported dimensions to modern life. For example, we are all used to multiple metrics to assess a nation’s economy, such as its GDP, trade deficit, rate of currency exchange and employment level.

There is currently some discussion over the need for additional emissions metrics. Indeed, as this book goes to press (2012), the UK’s all-party House ofCommons Select Committee on Energy and Climate Change is holding an enquiry into Consumption- Based Emissions Reporting, with the Select Committee’s conclusions due out at the end of the year. The good news is that the country’s Parliamentary Select Committees sometimes produce incisive reports. The bad news is that many Select Committees’ conclusions can be bland when it comes to a politically controversial topic such as this one, and sometimes they miss the point, especially where enquiries are on a technical topic, again as is this one. Furthermore, even if the Select Committee produces a bold report, the UK government is not obliged to adopt its conclusions (though it is obliged to respond to the points the committee makes) and, of course, other nations need not take any notice at all.

Nonetheless, proper accounting is vital if decisions are to be evidence-based: the null position being that the decision-making process is ill informed. Does anyone need reminding that the 2008–9 global financial crash was due to lack of accounting with due diligence, when sub-prime mortgages were incorrectly valued? Or that the Eurozone crisis that began in 2011 was caused by at least one nation’s ‘creative’ accounting of its national debt?

The importance of proper accounting for emissions is not just because accounting provides the evidence and the evidence needs to be sound (and this should be reason enough), but because the aforementioned financial crises were based on notional resources, not genuinely physical ones. In both these cases it was notional value (based on currency) at the root of the problems and not a real resource: it was not the failure of an agricultural region, or collapse of a mine, that caused the problem: crops carried on growing regardless of stock market performance. Conversely, climate change does affect agriculture (ask the farmers in Australia’s Murray-Darling basin), extreme precipitation does affect the physicality of homes (ask the residents of England’s Boscastle), sea-level rise does reduce land area (talk to people from Tuvalu) and the intensity of hurricanes is changing (a concern to those in the Caribbean and south-east USA), to take just a few examples. This puts the difficulties of the 2008– 9 and 2011–12 financial crises into perspective when compared with the real-world pressures on society that are arising out of climate change. Yet if we fall foul of purely human constructs of notional value, what will happen when real physical resources are diminished?

The second point that I feel is worthy of consideration is one that will be extremely challenging for my ecologist colleagues: the need to consider species and ecosystem translocation as part of global conservation and climate mitigation. Not only are some species threatened by climate change, and so arguably could do with a helping hand to colonise new areas, but ecosystems are one of the key ways the Earth system (or biosphere) is regulated. Past major carbon isotope excursions (CIEs) see carbon cascade (often – at least in part, if not in the main – biologically mediated) from one biosphere reservoir to another, be it soil carbon, oceans, wetlands and so forth, via the atmosphere. Reducing atmospheric carbon is difficult but in part might be achieved through the translocation of ecosystems based on climate projections together with Earth system considerations. This will not involve just forestation, but requires us to assist climate change-driven ecosystem change and succession. This is in contrast to maintaining ecosystems in their present locations in the manner of their current natural potential, which is the basis for much current ecosystem management (conservation). This is using biological systems to manage the cascade of carbon across the CIE event on which we are now embarked (irrespective of the triggering of any initial Eocene analogue) so as to help regulate the atmospheric carbon dioxide. It must be emphasised that this is not referring to forestation per se as we could plant many forests today only to see some of them release their carbon tomorrow as the world warms and biomes shift.

However, species translocation is not only controversial in itself (for some very good reasons, such as the unforeseen ecological impact of invasive species): some current ecosystems that might be considered for such management have international conservation status. Yet can we continue as we are and should we ignore ecological ways to manage the global carbon cycle? Such questions have so far largely been avoided but perhaps we need to start seriously considering them. Eventually, as climate change progresses, it is likely that policy-makers will start asking such questions and ecologists will be expected to provide the answers. Surely now is the time to start the debate in earnest. Here, the learned ecological societies across the world are among those best placed (but not the sole players) to facilitate this dialogue. These are just two personal thoughts that I present to you for consideration. It is likely that a number, if not many, reading this book are either already professionally in place to take forward discussion of one or other of these points, or will be so in the future (for instance, today’s students1). I leave it up to you.


1.) To facilitate any online discussion I will post this appendix as a page to which you can link. (This page is it.) Just search online for this appendix’s title.

Climate Change: Biological & Human Aspects 2nd edition (2013).

News update spring 2014: The following year (2014) the IPCC's Assessment Report 5 (AR5) Working Group II (WGII) report was published. It includes this concern that some species will not be able to move as biomes shift with climate change and that some species will not be able to keep up. Though readers of Climate Change: Biological & Human Aspects will have already discerned this.

News update summer 2014: The House of Commons Environmental Audit Select Committee has published its report in which it calls for the Government to initiate a public debate on managing species distribution in the face of climate change... Well, the final paragraph of Appendix 4 (above) does say that as climate change progresses, it is likely that policy-makers will start asking such questions and ecologists will be expected to provide the answers...