By Sarah Staniforth
Today, all over the world, museums are thinking about what sustainability means for them.
In the United Kingdom, the Museums Association has begun a dialogue about the economic, social, and environmental dimensions of sustainability. Economic issues have dominated museum concerns in the past two years, as governments have cut budgets for national and locally funded public museums and as independent museums have also struggled financially. Nevertheless, the social mission of museums remains strong, with education still at the heart of their purpose.
Environmental issues, on the other hand, have taken a backseat—until now. Increasing awareness of climate change, coupled with dwindling fossil fuels and spiraling energy costs, are causing museum managers to consider ways of reducing the carbon footprint of their institutions.
When the UK government signed the Kyoto Protocol, it agreed to reduce 1990 levels of carbon dioxide emissions by 12.5 percent by 2012. The long-term targets are a reduction of 42 percent by 2020 and 80 percent by 2050. Achieving these goals will require dramatic changes both in energy consumption and in the types of energy used. In 2007 the proportions were as follows:
The national goal is to have 20 percent renewables by 2020. Museums have to play a part by fulfilling their own targets for energy reduction. The UK's National Trust for Places of Historic Interest or Natural Beauty aims to reduce energy consumption by 20 percent by 2020 and to increase the use of renewables from 1 percent to 50 percent, compared with 2008.
ENERGY USE IN MUSUEMS
There are many ways to reduce energy use in museums, and there are also opportunities to generate energy on-site by microgeneration systems, such as wind turbines and solar panels.
Heating, ventilating, and air-conditioning (HVAC) systems are the greatest consumers of energy in many museums, particularly when temperature conditions inside differ significantly from those outside, and also when tight conditions of relative humidity (RH) are required. The typical environmental specifications that emerged in the second half of the twentieth century reflected what equipment could achieve—rather than what was necessary for collections. Because HVAC systems were capable of delivering RH and temperature control within tight limits (typically ± 2% RH and ± 1°C), the precautionary principle was adopted, and what actually constituted acceptable conditions for the conservation of collections was, for a time, ignored.
Ultimately, scientists conducting research into the museum climate—led by David Erhardt, Charles Tumosa, Marion Mecklenburg, and Mark McCormick-Goodhart at the Smithsonian Institution—revisited the issue of environmental specifications and concluded that greater flexibility was appropriate. In 1994 the Smithsonian issued a press release suggesting that a wider range of RH and temperature conditions, with fluctuations as great as ± 15% RH and ± 10°C, would be acceptable for the majority of collections.
The Getty Conservation Institute has focused on these issues for many years. In the late 1980s the GCI commissioned research that looked at reducing energy consumption in museums.¹ The Institute's preventive conservation training courses, held during the 1990s, debated appropriate environmental conditions for collections housed in museums in different parts of the world and looked at models of traditional building design as a way of informing new design. More recently, it has been researching museum lighting—work that is reevaluating current illumination guidelines and demonstrating that energy conservation and artifact conservation are fully compatible.²
Those of us who work with collections housed in historic buildings recognize that a wider range of environmental conditions does not dramatically increase damage to collections. In the United Kingdom, historic buildings are damp—particularly buildings that are not heated in the winter. Biological deterioration—rather than mechanical damage from RH fluctuations—is the biggest challenge for collections. Solar gain can reduce RH to below 65 percent in the summer. Conservation heating is used in National Trust and many other historic UK buildings to keep the RH below 65 percent in the winter. Apart from that, there is little active control of RH levels.
Discussions have been held among heads of conservation at UK national museums and heritage organizations, and in 2008 a set of principles was embraced for reducing a museum's carbon footprint.³
- Environmental standards should become more intelligent and better tailored to clearly identified needs of collections and visitors.
- Care of collections should be achieved in a way that does not assume air-conditioning.
- Natural and sustainable controls should be explored and make maximum use of buildings with high thermal mass, high thermal insulation, low air exchange rates, local control using microclimates, glazed and backed paintings, and the maximizing buffering effect of building materials.
- Architects and engineers should be guided to reduce significantly the building's carbon footprint as a primary objective.
As part of these principles, interim guidelines for environmental conditions have been proposed. For the majority of objects containing hygroscopic material, a stable RH is required in the range of 40 to 60 percent and a stable temperature in the range of 16°C to 25°C. More sensitive materials will require RH control that is tight and specific—specific according to the material. Less sensitive materials can have wider parameters for RH and temperature.
Some commentators have described these proposals as a relaxation of environmental conditions. However, in actuality, these are appropriate environmental conditions for the majority of objects in collections. Indeed, these proposals have been accepted by the Bizot Group of museum directors involved with international loan exhibitions in 2009. They have been discussed at a number of international conservation meetings, including in Copenhagen in March 2010 at the Museum Climate and Global Climate Change Symposium; at a meeting coorganized by the Boston Museum of Fine Arts and the Getty Conservation Institute for heads of conservation in North American museums in April 2010; and at the IIC roundtable discussion at the AIC conference on "The Plus/Minus Dilemma: The Way Forward in Environmental Guidelines" in May 2010.
However, we should not let environmental specifications distract us from other measures that can be used to save energy. Simple measures such as turning off equipment, using more energy-efficient equipment such as condensing boilers, increasing thermal insulation, reducing air leakage, and not using highly processed materials can all contribute. Any opportunity to switch to renewables as part of capital expenditure projects should be considered. Museums in sunny parts of the world could use their roofs for solar panels; it is now possible to get transparent solar panels that can be used to replace glass in skylights. In addition, land around museum buildings can be used for ground source heat pumps, and fossil fuels can be replaced with biomass.
SUSTAINABILITY OF MUSEUMS
Many museums are suffering under extreme weather conditions as a result of climate change, most recently in northern Australia, where a particularly strong El Niño effect this year caused torrential rain and strong typhoon weather systems. Emergency procedures are put into action more and more often, even in the United Kingdom, where our temperate climate has protected us from extreme weather until the past five years; increasingly severe rainfall has flooded numerous museums and historic buildings with rainstorms occurring at the one-in-one-thousand-year level. This rainfall not only floods buildings at ground level but also overwhelms the capacity of gutters and downpipes to disperse water off roofs.
We need to find ways to adapt to a changing climate, to make museum buildings more resilient in the face of extreme weather events, and to mitigate further climate change by reducing energy consumption and changing from fossil fuels to renewables.
The future for collections and museums can be seen as gloomy or as an exciting challenge, but we need to take action now. In the words of Johann Wolfgang von Goethe, "What is not started today is never finished tomorrow."
Sarah Staniforth is the museums and collections director at the National Trust in the United Kingdom.
1. J. Marx Ayres, J. Carlos Haiad, and Henry Lau, Energy Conservation and Climate
Control in Museums (Marina del Rey, CA : Getty Conservation Institute, 1988).
2. See Museum Lighting Research.
3. See National Museums Directors' Conference Guiding Principles for reducing a museum's carbon footprint.