Air conditioning has remade the policy. Now that’s the key to navigating climate change.


Record and sustained temperatures this summer in Europe, the United States and other parts of the world have highlighted both the benefits and the challenges of a global society increasingly dependent on air conditioning. In places where air conditioning is unusual or non-existent, the record heat is taking its toll.

In much of the United States, however, air conditioning is quite ubiquitous. Technology grew and developed here critically and helped shape the politics and history of the United States itself. Its spread across the country — in early DC, then across the South and the Sun Belt — has helped transform the movement of Americans and the regional distribution of political and economic power since World War II. This story shows how changes in the built environment have contributed to the climate crisis and highlights the urgency of transforming our buildings to mitigate its effects.

Initially in the early 20th century, air conditioning was developed in the United States to increase economic productivity, by making industrial workplaces and then public spaces such as movie theaters more comfortable for workers and consumers.

This extended to Capitol Hill, where, beginning in the 1920s, Congress, after much debate, appropriated funds for the air conditioning of the U.S. Capitol and nearby House and Senate office buildings. Air conditioning has transformed the annual cycle of Congress activity. Before air conditioning, a session of Congress typically lasted less than 300 days, adjourning in late June for the summer. The city was largely deserted from mid-June to September, even during a time of national crisis. Yet in the years after 1938, when air conditioning became operational throughout Capitol Hill, Congress held sessions beyond 300 days and beyond late June when heat waves set in. on Washington. Air conditioning reduced calls for an early adjournment.

Air conditioning also transformed daily bureaucratic life in buildings such as the Pentagon, which had the world’s largest air conditioning plant in a single structure when it opened in 1943. In the 1950s, the General Services Administration found that productivity in government offices increased by 9.5. percent when air conditioning was installed. In Washington, where high temperatures of 106 degrees and 60% humidity had been recorded, air conditioning, “far from being a mere luxury”, proved to be “essential to the normal operational efficiency of the staff”.

The experience of many Washington federal employees with air conditioning at work has been a key factor in increasing demand in other settings, including department stores, theaters, hotels and other commercial sites seeking to attract more of consumers.

Rationing of electrical power and equipment during World War II initially slowed local adoption of air conditioning in DC. But as early as 1942, the area’s Potomac Electric Power (Pepco) became the first utility peak in the country’s summer, meaning that more electricity was used in the summer to support air conditioning than was used in the winter to power heating equipment. In 1953, Washington had more air conditioning per capita than any other US city. In 1966, approximately 56% of Pepco’s residential customers, including those in the suburbs, had some type of air conditioning; by 1981, that number had risen to almost 90%.

Washington’s transformation anticipated the effects of air conditioning in the South and the Sun Belt. Its ability to mitigate the effects of the Southern climate made the South and Southwest attractive for industrial and related population growth, shifting economic and political power from its traditional centers on the East Coast and into the Midwest. It has made places that are intolerably hot in the summer livable and made some, from Southern California to Florida, attractive to retirees, white-collar new industries and other newcomers year-round. Improving the indoor environment with air conditioning also extended the Southern school year by addressing, as one observer noted in 1946, “without question, one of the greatest obstacles to a greater progression of education in the Deep South”. That is, “the physical conditions under which faculty and students must work”.

In 1940, the most populous states were New York, Pennsylvania and Illinois. Swelling populations in Florida, Texas, and California made them the three most populous states in 2015. Between 1940 and 1980, warmer states collectively got 29 electoral college votes, while colder states in the Northeast and Rust Belt lost 31. From 1900 to 1948, only two presidents or vice presidents came from Southern states, but from 1952 to 2004, every winning presidential ticket included at least one of these candidates.

Air conditioning has not only shaped the United States, but also the world. Although it is even less widespread in Europe, it is growing there. Japan adopted air conditioning in commercial buildings in Tokyo in the 1930s, and the technology advanced rapidly there, including in homes, from 1960 to 1990. Yet in southern India there was very little air conditioning until the mid-1990s. In China, in 1999, about 20% of urban households had air conditioning units; by 2007, this figure had risen to 80%. For equatorial nations like Singapore and perennially hot regions like the Persian Gulf, air conditioning has been crucial for development.

A key issue is that air conditioning has always been energy-intensive. In 2000, 48% of the energy consumed by buildings in the United States (the largest component) was used for comfort cooling and refrigeration. The release of carbon dioxide and other greenhouse gases into the atmosphere from fossil fuels involved in powering air conditioning has made it central to climate change.

A fundamental dilemma is that as global warming increases, the world will need more air conditioning, but air conditioning is one of the technologies that increases global warming.

Its centrality both as a technology essential to global health and comfort and as a contributor to global energy demand and global warming means that it is incumbent on the global community to develop technologies and policies that will allow us to access the advantages of this modern mechanism while reducing its excessive consumption. resources and negative effects on the environment.

Just as air conditioning has transformed where and how we live, efforts to mitigate the harms of climate change focus in part on how we approach our built environment. Since the late 1970s, states have recognized the importance of reducing energy consumption in buildings and have adopted policies to reduce the reliance of air conditioning on electricity generated by burning fossil fuels. At the beginning of the 21st century, the culture of green building developed rapidly. Improved material envelopes for buildings, mechanical systems that consume less energy, and digital monitoring of these systems have reduced energy consumption. Passive house standards, zero carbon buildings and net zero energy buildings are concepts that have taken hold in the developed world, where air conditioning use is highest per capita, with commitment and ever-expanding cooperation between building owners, architects and engineers, state and local governments, and utilities to reduce the energy consumption of buildings.

The U.S. government has been active in research and development of energy-efficient buildings since the 1970s. In 2006, the GSA indicated that it would only use the LEED (Leadership in Energy and Environmental Design) of the US Green Building Council to evaluate federal projects. According to one account, as of 2018 the United States had reduced the energy intensity of federal buildings by 50% since 1975. More recently, much has been accomplished through programs such as the Better Buildings initiative of the Department of Energy. And the US efforts are just part of a global push for green buildings, from China to Germany to Dubai, among many countries.

It has long been recognized that the climate effects of reducing the energy consumption of buildings are potentially significant. A 2008 report from the US National Science and Technology Council claimed that even then, technology existed to reduce energy consumption in new buildings by about 70% compared to conventional standards.

Since then, many other tools for significantly reducing energy consumption in buildings have been developed and an international network for sharing information about them has grown. Today, there is broad consensus that the historical energy and environmental effects of technologies such as air conditioning can be significantly reduced through technically feasible solutions, so that our future does not have to repeat our past. This goal is within reach if societies can maintain the political will to encourage their implementation. Technologies such as air conditioning have changed the terrain on which we do politics. We’re in a time when politics can help reshape energy-guzzling technologies in the built environment to keep us and the planet cool.

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