Environmental Audit CommitteeWritten evidence submitted by Dr Mayer Hillman, Senior Fellow Emeritus at Policy Studies Institute, University of Westminster

COMMENTS ON THE QUESTION OF POSITIVE FEEDBACK IN CLIMATE MODELLING

The concentration of carbon dioxide in the global atmosphere is clearly linked to climate change. It is not only rising alarmingly but, it would appear, doing so exponentially. It has now reached a level not experienced on the planet for millions of years. One does not have to be a climate scientist to understand that there are contributory factors to this other than the direct one of fossil fuel burning.

It is recognised, not least by the UKMO, that a major one is the process of feedback from this burning which is resulting in higher temperatures and thus leading to the level rising still further. The melting of the polar ice caps and loss of snow cover in the tundra regions of Russia and Canada, for example, is seriously diminishing the albedo effect of that cover and releasing growing volumes of methane, a far more potent greenhouse gas than carbon dioxide. Higher temperatures, as well as deliberate felling of significant areas of tropical rainforests, are a source for extreme concern about the consequences of the loss of their “sink” function in limiting the rising level of carbon dioxide in the atmosphere.

It stands to reason that policy formation employed in determining reliable targets to counter the worst effects of climate change are wholly unreliable unless all the feedback effects are incorporated into the modelling process, as far as is at all possible. And insofar as they cannot be incorporated owing to the unavailability of research evidence, that should be made explicit so that this omission is fully reflected in the advice given to policy makers.

To date, the UKMO has not done this. The outcome of the omission is seriously misleading. Given that there are growing grounds for realising that emissions from the feedbacks may well be exceeding those from the direct burning of fossil fuels, this grave aspect of policy needs to be satisfactorily and transparently rectified as a matter of extreme urgency.

Otherwise, politicians, within and outside the Coalition, civil servants within the various government departments, local authorities, the business community and those active in the various fields of relevant policy will continue to take as the received scientific wisdom that the target agreed by the main political parties of an 80% reduction by 2050 on carbon dioxide emissions on the 1990 level (as contained in the Climate Act)—whilst hugely challenging—nevertheless represents a target that reliably reflects the level of concentrations of the emissions in the decades ahead, thus enabling determination of adequate policy changes needed to prevent irreversible climate change.

15 July 2013

Prepared 3rd October 2013