Environmental sustainability generally refers to the balance between the consumption and the production of resources. By definition, the use of non-renewable resources implies permanent environmental damage, while the use of renewable resources can mitigate this problem. Material consumption can be measured in a number of ways including global warming potential, land use competition, and human toxicity. Taken together, an environmentally-weighted material consumption value can be formulated .
Figure 1. Relative contribution of groups of finished materials to total environmental problems (total set at 100%) .
The Sustainable Consumption & Production Branch of the United Nations Environment Programme (UNEP) reports that the relative contribution to the total environmental problems caused by material consumption is led by Animal Products (34.5%), Crops (18.6%), and Coal (14.8%). See Figure 1 adapted from . These environmental problems result in a combination of emissions and waste. Emissions can broadly be classified as air and water pollution.
The impact of human activity on sustainability in terms of anthropogenic pollution, including chemical and biological wastes, has affected biodiversity, climate, and human health. In particular, air pollution data from the United States Energy Information Administration (EIA)  and the United Nations Food and Agriculture Organization (UN FAO)  report the three primary causes of the production of anthropogenic greenhouse gases (GHG) to be buildings (48%), the meat industry (18%) and transportation (14%). Each of these industry sectors has previously operated in a business environment where GHG production was not a concern. However, as these problems are identified, and as citizen and consumer demand turns to significantly reduce air pollution, a number of interrelated issues surrounding these problems (from climate change, to diet, to building efficiency) enter the global narrative.
CHI Sustainability Community
We believe that the CHI community can have a major positive impact on these problems. Specifically, through a CHI Sustainability Community, information from related disciplines critical to the understanding of these problems can be brought to the broader HCI community in support of researchers interested in applying their knowledge-bases to sustainability. In this way, CHI can show leadership in this important emerging field. The CHI community has already demonstrated a unique and impressive ability to cross multidisciplinary bridges and this same skill will be central to any progress made in this area. At CHI 2010, sustainability-related publications have started to examine trans-theoretical modeling, supply-chain carbon accounting, water conservation, indoor air quality, power usage and the role of feedback .
Approach to Community Growth
To estimate the current the size of the CHI sustainability community, we draw on the data collected by DiSalvo et al.  who found 157 papers from 2009 that have sustainability in HCI as a central focus. At CHI 2010 approximately a dozen papers related to sustainability were presented and a similar amount of work will presented at CHI 2011. While this is a good start, it falls short of the full impact that the CHI community can have in the area of sustainability.
There are two major areas where additional researchers could be brought to CHI, or where existing CHI researchers could refocus their efforts. First, as highlighted by DiSalvo et al., a large number of design professionals and engineers, who already understand their role in sustainable design, could greatly benefit from seeing HCI advancements in their tool sets. Second, the entire domain of modeling and simulation is a critical tool for addressing areas of great complexity precisely like sustainability, and our community must include support for this domain. In addition to these two, a number of current HCI topics, such as large displays, feedback, social networks, mobile computing, infoviz, ubicomp, and end-user programming could all be refocused on sustainability problems to great benefit for the environment. Finally, researchers in more geographical regions could be motivated to participate, reflecting the global aspect of the challenges we are considering. Participants and volunteers can be recruited in all of these ways and, in fact, must be included given the massive scale of the problem space. Overall, we can help architects to design more efficient buildings, help food consumers to make more sustainable food choices, and help consumers to reduce indirect and direct transportation usage. In general, designing interactions that support real consumption and production decision-making will be critical. Our goal is to see 20% of CHI working on sustainability.
Azam Khan, May 2011
References and Citations
 DiSalvo, C., Sengers, P., and Brynjarsdóttir, H. (2010). Mapping the landscape of sustainable HCI. ACM CHI. pp. 1975-1984.
 Hertwich, E., van der Voet, E., Suh, S., Tukker, A, Huijbregts M., Kazmierczyk, P., Lenzen, M., McNeely, J., Moriguchi, Y. (2010). Assessing the Environmental Impacts of Consumption and Production: Priority Products and Materials, A Report of the Working Group on the Environmental Impacts of Products and Materials to the International Panel for Sustainable Resource Management. United Nations Environment Programme.
 Kaye, J. (2009). Some statistical analyses of CHI. ACM CHI alt.chi, pp. 2585-2594.
 Mynatt, E. Ed. (2010). CHI '10: Proceedings of ACM CHI. ACM CHI.
 Steinfeld, H., Gerber, P., Wassenaar, T., Castel, V., Rosales, M., de Haan, C. (2006). Livestock’s Long Shadow: Environmental Issues and Options. Food and Agriculture Organization of the United Nations.
 U.S. Energy Information Administration (2008). Assumptions to the Annual Energy Outlook. US EIA.