In his iconic publication The Museum Environment, Garry Thomson stated that the museum world's practices relating to international loans could potentially steer institutions toward a specific temperature and relative humidity (RH) range, regardless of the climate in which an institution might be located, the type of collection it preserved, or the environmental conditions to which the collection had historically been exposed. Thomson's prescience would be borne out. The convenience of a simple set of numbers that might be universally applied and somehow universally appropriate was too tempting to resist. Over recent decades, museums specified climatic conditions within a "safe" narrow range, not only for loans but also for permanent exhibition and storage spaces. This specificity resulted in large capital investments in mechanical systems and escalating operating costs, as the energy needed to fuel such systems became increasingly expensive.
There was, however, a recognition—slow to form but persistent once it did—that a "one size fits all" approach to environmental specifications for collections in general was often unattainable, not based on evidence, and quite possibly unnecessary. Calls were made by Jonathan Ashley-Smith, then head of conservation at the Victoria and Albert Museum, and by others for a more honest look at environmental parameters since the experience of borrowing and lending institutions indicated that some objects might be more robust than otherwise thought.1
Nonetheless, museum practice with respect to environmental conditions for collections had remained largely unchanged by the time a group of museum directors openly questioned long-standing protocols relating to loan requirements. In 2008 directors associated with the International Group of Organizers of Large-scale Exhibitions, also known as the Bizot Group, expressed concern about the sustainability of long-established practices for loans—and by extension for collection conditions more generally—sparking a debate throughout the conservation community over the necessity of tight, prescriptive environmental specifications.
Museum environmental research and experience over recent decades has strongly suggested that some collection materials may be able to withstand a wider range of temperature and RH conditions without risk of damage. Yet there remains some dispute and uncertainty within the conservation field about the potential longer-term impacts a more liberal approach to environments would have on collections.
MANAGING COLLECTION ENVIRONMENTS INITIATIVE
In 2013 the GCI launched the Managing Collection Environments initiative (MCE) to explore some of the issues relating to collection environments with which the field is wrestling. Building on the GCI's previous experience in preventive conservation, MCE functions as an integrated program of research, education, field activities, and information dissemination.
Through its various activities, the initiative addresses a range of research, policies, and practices pertaining to the field's current understanding of the museum environment and to the actions generally taken to manage climate conditions for collections in a safe and sustainable manner. MCE is targeting a number of factors that are seen as contributing to lingering uncertainty within some corners of the field, including gaps in research (specifically a lack of data and quality of evidence); limited collaboration and practical examples or case studies; policies that are not being revised at the institutional level; and the difficulty of decision-making where a high degree of uncertainty can exist.
Research: Quality of Evidence
Given the lack of data to support climate strategies based on evidence of damage in historic objects caused by fluctuations in temperature and RH (often referred to in conservation as climateinduced damage), MCE has undertaken research that can provide a better understanding of the behavior of the material. There are two significant knowledge gaps in understanding the impact of environmental conditions on historic materials sensitive to moisture: the variation in mechanical properties across a typical collection and the way aging affects the mechanical properties of different materials. Research into material change has often used mock-ups with new materials, but recommendations for environmental conditions based on such samples have been controversial, since artificial aging of new materials does not reflect the complexity of compounded physical and chemical processes occurring over centuries.
To narrow this knowledge gap, MCE is applying small-scale engineering techniques such as micro- and nano-indentation to historic materials. These methods offer a means of material characterization that enables examination of submillimeter samples in various microclimatic conditions. Because micro- and nanoindentation are virtually nondestructive—cross-sectional samples of historic material are not chemically altered during measurement, and tests leave only minimal physical markings—subsequent examination of these samples is possible. These studies have enabled systematic examination of mechanical properties of historic paints for the first time and provide opportunities for nano-indentation data to contribute to predictive models of material behavior.
However, connecting laboratory research with practical field studies remains the biggest challenge. This problem is addressed by MCE through an experimental program on a small collection of historic (nonmuseum) wooden objects exposed to a set of predefined climate fluctuations. The aim of the program is to explore the potential for accurately and quantitatively tracing the response of wood to climatic changes, combining a suite of monitoring techniques: acoustic emission, physical measurements, photography, and high-resolution 3-D scanning
This ongoing research offers insight into responses of naturally aged objects to climate variations, including indications of relationships between response and specific climate history. Through this research, it is possible to analyze the sensitivity of this suite of methods to fracturing, cracking, and deformation, and also to better understand the quality of data gathered with these techniques. Once a suitable monitoring protocol is established, this research can be used to answer pertinent questions that have eluded the field, such as the role of existing damage in object response.
These developments will inform best practice for monitoring change and should help improve the quality of data gathered in research projects and field studies. Understanding critical conditions leading to damage for mixed museum collections is equally important. While research remains in progress, collected data already show that objects having acclimatized to their climate history is an important consideration when recommending fluctuation levels
Practice: Collaboration and Dealing with Uncertainty
Although MCE's research will increase understanding of the behavior of materials and thereby contribute to our knowledge of what may constitute a "safe" environment, it is also clear that science alone cannot entirely remove professional reservations regarding changes to a collection's environment. The many variables in material, construction, and other factors mean that scientific experiments cannot cover every possible situation. Of more importance is that what constitutes "damage" is subjective and varies with context. Therefore, MCE also addresses decision-making in the face of uncertainty, which requires collaboration among several of the professions involved in the operation of a cultural heritage institution. Making decisions based purely on the needs of the collection is not feasible—human comfort, the building's capabilities, and organizational resources are also key factors. Decision-making should take into account all these factors and involve different stakeholders with varied levels of engagement and decision-making powers. These colleagues often bring knowledge about specific parts of the process, as well as different perspectives, to the table. While scientific research can inform practical strategies, ultimately collection, building, and human needs have to be balanced with an institution's mission and capacity, external challenges such as extreme climates, and constrained resources.
To specifically address decision-making in the context of the practical business of collections care, MCE has created a professional development program that will include a variety of workshops, meetings, and longer courses. The centerpiece of this program is the Preserving Collections in the Age of Sustainability course, which is intended for decision makers involved in collection preservation, including conservators, facilities staff, registrars, and collection managers. The initial nine-month course, held in 2017, consisted of three phases, beginning with a ten-week online component of readings and assignments that ensured participants would be prepared for discussion and reflection. The second phase consisted of a two-week intensive workshop at the Pennsylvania Academy of the Fine Arts in Philadelphia, which featured lectures and discussions encouraging the diverse group of participants to draw out the complexities of featured case studies. The third phase, a distance mentoring phase directly following the workshop, assisted participants in implementing ideas from their action plans (drawn up during previous phases of the course) within their own institutions, working with their colleagues
The course considered a range of topics pertinent to the environmental management of collections. By aligning presentations of up-to-date research with discussions of case studies and their individual situations, course participants had an opportunity to reflect on their current practices and lay a foundation for lasting institutional change. The course's emphasis on both technical information and interpersonal skills such as communication, negotiation, and leadership underscored the need to move away from prescriptive solutions and quick fixes and toward a comprehensive analysis of the present situation, collaborative decision-making, and long-term goals tailored to the specifics of a given museum—its building, its location, the nature of the collection, its programming, and its resources.
The course curriculum was designed to be flexible and adaptable to different locations, cultural contexts, and climate zones. The MCE team plans to offer the course at approximate two-year intervals with various partners both within the United States and internationally.
To increase the number of examples that reflect this kind of decision-making, MCE has begun to develop field activities with partner institutions to produce real-life examples of the decision making process as it relates to different types of museums, collections, climates, and challenges. These will lead to case studies that will be incorporated into future courses and published as technical reports.
Policy: Influencing the Debate
Existing policy and practice can always be an obstacle to change, even when there is a better understanding of the risks of climate-induced change to collections. As Garry Thomson predicted, international loan agreements too often stipulate climate requirements for objects around a moderate RH set point, regardless of the climate in which an institution is located or the type of collection it preserves. It has been up to the borrowing institution to accommodate these requirements. Adhering to tight parameters in loans prevents institutions from moving toward more sustainable approaches. It is therefore important for the field to openly discuss the impact on international loans of evidence-based approaches for individual institutions that employ risk management methods instead of default ranges, and to consider how the negotiation and enablement of loans can be facilitated.
Reference points, such as standards and guidelines, also need updating so they can be more helpful in various decision-making processes. To this end, members of the MCE team have joined with professional colleagues in efforts designed to influence environmental management policies. One of these is participation in the revision of the 2015 ASHRAE Handbook—HVAC Applications: Chapter 23, Museums, Galleries, Archives, and Libraries (the handbook for the American Society for Heating, Refrigerating and Air-Conditioning Engineers), alongside other international experts in the cultural heritage field, including conservation scientists, conservators, preservation architects, and engineers. One of the proposed revisions is the reinforcement of a starting point for climate control specifications that is no longer the historically perceived optimum of 50% RH and 70°F/21°C but is instead the historical climate average to which a certain collection and building have been acclimatized (with broad limits to avoid universal problems like mold). The guidance therefore accounts for acclimatization of objects to different environments and institutions located in different climate zones. It also separates the guidance for permanent collections from loans that may have come from environments with different climatic ranges. These changes should result in environmental strategies that could be easier to achieve with nonmechanical controls (such as building envelope improvements) and limited mechanical intervention at a more affordable cost to the institution, without endangering collections by placing them at risk of climate-induced damage.
A HOLISTIC APPROACH
What makes MCE unique in its approach is that it addresses the challenge of rethinking collection care environments from a variety of angles. Designing environmental strategies for collections requires new technical data and new decision-making processes that involve the input of different stakeholders. Environmental management for museum collections is not the sole responsibility of conservators and conservation scientists. As the field advances in this area, the holistic approach has the advantage of advocating for conditions that not only are safe for collections but also are more economically and environmentally sustainable.
Foekje Boersma is a former GCI senior project specialist and project manager of MCE (2013 to early 2018). Joel Taylor is a GCI senior project specialist. Kathleen Dardes is head of the GCI Collections department. Michal Lukomski is a GCI senior scientist.
1. Jonathan Ashley-Smith, Nick Umney, and David Ford, "Let's Be Honest"—Realistic Environmental Parameters for Loaned Objects," in Preventive Conservation: Practice, Theory and Research–Preprints of the Contributions to the Ottawa Conference, 12–16 September 1994 (London: IIC, 1994), 28–31.