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Climate Digest for October 2009
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Climate impacts
Adaptation
Risk, uncertainty and decision-making
Climate impacts
1 Changes in internal temperatures within the built environment as a response to a changing climate
This paper explores the possibility of being able to use a set of coefficients to describe the expected response of any building to external temperatures. In order to use this methodology, Coley and Kershaw demonstrate a linear response between external temperatures and the internal temperatures of a variety of different buildings.
To ensure that this methodology works under a range of climate futures, several scenarios were modelled within the Integrated Environmental Solutions (IES) dynamic simulation environment. This procedure models the radiative, conductive and convective heat exchange between the building and both the internal and external environmental factors. Thermal capacities of the buildings were varied by changing the construction materials.
It was found that the relationship between external and internal temperatures are always linear within a certain construction type. Therefore two simulations of a building’s response to external temperature is enough to identify the gradient and hence the coefficient that can be used to calculate the response of the building to any external temperature change.
Use of this methodology would allow for more rapid thermal modelling of buildings with respect to their response to climate change and allow for a more cost-effective design of resilient buildings in the future.
Source: Coley, D and Kershaw, T. Changes in internal temperatures within the built environment as a response to a changing climate. Building and Environment 45 (2010): 89–93
2 The British river of the future: How climate change and human activity might affect two contrasting river ecosystems in England
This paper states that the potential impact of climate change on the UK and European lowland river ecosystems as a whole have so far received little attention but that the worldwide reduction in freshwater biodiversity to date is believed to have exceeded that in terrestrial or marine environments (Jenkins 2003) and this may be due to declining river flows. The pressure on river systems is expected to increase in terms of flow volumes but also in quality. An increased pressure on the ecosystems of southern England river systems can be expected from an expanding population, possible climate change impacts and the Water Framework Directive stipulating that water quality be maintained or improved.
The paper explains how the climatic impacts on hydrology and chemistry were modelled for the contrasting catchments of the Thames and the Yorkshire Ouse. These potential changes to flow, temperature, sunlight and chemical composition were used as a guide to help judge how a range of different aquatic organisms, from microscopic to macroscopic, might respond.
The CLASSIC hydrological model, driven by output from the Hadley Centre climate model (HadCM3), based on IPCC low and high CO2 emission scenarios for 2080 were used as the basis for the analysis. Compared to current conditions, the CLASSIC model predicted lower flows for both rivers, in all seasons except winter. The paper establishes the following.
- Such an outcome would lead to longer residence times (by up to a month in the Thames), with nutrient, organic and biological contaminant concentrations elevated by 70–100% pro-rata, assuming sewage treatment effectiveness remains unchanged.
- Greater opportunities for phytoplankton growth will arise, and this may be significant in the Thames. Warmer winters and milder springs will favour riverine birds and increase the recruitment of many coarse fish species.
- However, warm, slow-flowing, shallower water would increase the incidence of fish diseases.
These changing conditions would make southern UK rivers in general a less favourable habitat for some species of fish, such as the Atlantic salmon (Salmo salar). It also stated that unless there is a drastic reduction in the nutrient load for much of the year, the rivers will probably be a much darker shade of green than they are at present.
Source: Johnson, A., Acreman, M., Dunbar, M., Feist, S., Giacomello, A.M., Gozlan, R., Hinsley, S., et al. The British river of the future: How climate change and human activity might affect two contrasting river ecosystems in England Science of The Total Environment, Vol. 407, August 2009, 17, 4787–479. doi:10.1016/j.scitotenv.2009.05.018
Reference cited: Jenkins, M. Prospects for biodiversity. Science 2003; 302:1175-7
Adaptation
3 Climate change: motivation for taking measures to adapt
General accounts of the theory of climate change adaptation rarely recognise belief in climate change, or one’s capacity to adapt, as prerequisites to adaptation. For example, adaptation has been variously described as adjustments in ecological-socio-economic systems in response to actual or expected climate stimuli, their effects or impacts, and as local or community-based adjustments to deal with changing conditions within the constraints of the broader economic-social-political arrangements. Awareness of the role of psychological and cognitive aspects of adaptation is growing, but little attention has as yet been paid to it.
This paper addresses that gap by examining the significance of strength of belief in climate change and strength of belief in adaptive capacity amongst forest owners in Sweden. 1,950 forest owners were asked:
- Do you believe that the climate is changing to such an extent that it will substantially affect the forest?
- Has the climate change debate affected your forest management?
- If not, why has the climate change debate not affected your forest management?
Results revealed a significant and positive association between adaptation action and strength of belief in climate change and strength of belief in adaptive capacity, suggesting that individuals need to both believe in climate change, and believe they have the power to do something about its consequences, if they are to take steps to adapt. This finding challenges the assumed view that adaptation is a function of economic-social-political factors and highlights the importance or cognitive factors in realising adaptation in action.
Source: Blennow, K. And Persson, J., Climate change: motivation for taking measures to adapt. Global Environmental Change 19, 2009 (1): 100–104.
Risk, uncertainty and decision-making
4 Willingness of homeowners to mitigate climate risk through insurance
This paper starts by quoting the IPCC (2007) that climate change is expected to increase the frequency and severity of flooding in certain regions as the warmer climate is likely to result in a more vigorous hydrological cycle with more precipitation and associated flood risk. At the same time sea level rise may increase the flooding risk to low lying areas from storm surges. In the Netherlands this is a serious problem due to the vulnerability of extensive low lying areas. Even if current climate policy could stabilize greenhouse gases to 2000 levels, a further warming of around 0.2C would still occur in the next 20 years. As increases in urbanisation in flood prone areas is expected to occur during this same period, the potential for serious economic damage is increasing. This paper suggests that land use policy requires an innovative and adaptive approach to cope with the increased flood risk and associated economic impacts. Increasingly, attention is paid to the role insurance can play in mitigating damage by providing incentives to policyholders to undertake measures to reduce potential damage. Surveys were undertaken in parts of the Rijn river basin to examine the willingness of homeowners in the Netherlands to undertake flood damage mitigation measures in response to hypothetical incentives driven by insurance policies. The mitigation measures offered were those that past experience had shown to be the most effective options (ICPR 2002). The results indicate that many homeowners are willing to make investments in mitigation. In particular;
- approximately two-thirds are willing to invest in water barriers in exchange for a premium reduction;
- about a fifth are willing to replace floor types that are vulnerable to flooding with water resistant floor types; and
- about a quarter are willing to move central heating installations to floors safe against flooding in favour of a reduction in the insurance premium.
Estimates of the effectiveness of these mitigation measures to limit potential flood damage in the river delta indicate that prevented economic impacts of flood damage could be substantial, in the order of €1 billion or more.
Source: Botzen, W.J.W., Aerts, J.C.J.H., van den Bergh, J.C.J.M. Willingness of homeowners to mitigate climate risk through insurance Ecological Economics, Volume 68, 15 June 2009, Issues 8–9, Pages 2265–2277. doi:10.1016/j.ecolecon.2009.02.019
Reference cited: IPCC, 2007. Climate change 2007: the physical science basis. In Solomon, S., Qin, D., Manning, M., et al. (Eds.), Contribution of Working Group 1 to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. Cambridge and New York.
Reference cited: ICPR, 2002. Non structural flood plain management: measures and their effectiveness. International commission for the protection of the Rhine (ICPR), Koblenz.
5 Policy responses to rapid climate change: An epistemological critique of dominant approaches
As its title suggests this paper focuses on some of the basic assumptions which underlie existing climate policy, particularly regarding the validity of these assumptions as a basis for policy response to the possibility of rapid climatic change.
The paper reviews some of the literature on the likelihood of rapid climatic change and finds that while it is played down as unlikely in many reports, not least the IPCC AR4, the probability of rapid change is highly uncertain. Furthermore much of this uncertainty is irreducible in principle and is not likely to diminish over time.
Having established the principal of rapid unpredictable climatic change as a real possibility, albeit a highly uncertain one, the authors turn to scrutinise existing climate policy.
They find that there are two groups of assumptions which they summarise as prediction and economic utilitarianism. The assumptions categorised as concerned with prediction are:
- we need more knowledge so we can know just how far to push the climate system;
- humans can know what level of stress we can cause the earth system before it changes states;
- ‘experts’ can tell us this;
- all tipping points will be imagined and identified;
- levels of stress before tipping points are reached can be identified and measured robustly enough, and soon enough to allow avoidance of tipping points, despite significant inertia.
Assumptions concerned with economic utilitarianism are:
- humans could and should get as much material benefit from the earth system as possible within legal and earth system limits
- economic cost-benefit analysis captures the range of human values within and between cultures.
The authors contest the validity of these assumptions as the basis of climate policy and suggest 5 possible alternative approaches: i) a modest, more piecemeal approach not reliant upon exact prediction, based upon plausible alternative future climate states; ii) technical solutions believed on the basis of a life-cycle assessment to reduce stress on the Earth’s system; iii) precautionary Principle (PP), promoting action to tackle climate change without the need for perfect knowledge, but rather seeking to avoid the potential risks; iv) virtue ethics and epistemology with emphasis on moderation, prudence and hope; and v) discursive democracy, democratising policy by encouraging a more open and participatory approach rather than limiting policy decisions to a small group of experts. Furthermore they suggest that given that climate change might be the biggest challenge ever faced by humanity, the ethical basis for climate policy and the governance of global environmental change should urgently be held up for scrutiny.
Source: Charlsworth, M. & Okereke, C. (In Press) Policy responses to rapid climate change: An epistemological critique of dominant approaches. Global Environmental Change, doi: 10.1016/j.gloenvcha.2009.09.001
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