Global Warming Will Explode Air Conditioning Demand

The United States has long con­sumed more energy each year for air con­di­tion­ing than the rest of the world com­bined. In fact, we use more elec­tric­ity for cool­ing than the entire con­ti­nent of Africa, home to a bil­lion peo­ple, con­sumes for all pur­poses. Between 1993 and 2005, with sum­mers grow­ing hot­ter and homes larger, energy con­sumed by res­i­den­tial air con­di­tion­ing in the U.S. dou­bled, and it leaped another 20 per­cent by 2010. The cli­mate impact of air con­di­tion­ing our build­ings and vehi­cles is now that of almost half a bil­lion met­ric tons of car­bon diox­ide per year.

Yet with other nations fol­low­ing our lead, America’s century-long reign as the world cool­ing cham­pion is com­ing to an end. And if global con­sump­tion for cool­ing grows as pro­jected to 10 tril­lion kilowatt-hours per year—equal to half of the world’s entire elec­tric­ity sup­ply today—the cli­mate fore­cast will be grim indeed.

Because it is so deeply depen­dent on high-energy cool­ing, the United States is not very well posi­tioned to call on other coun­tries to exer­cise restraint for the sake of our com­mon atmos­phere. But we can warn the world of what it stands to lose if it fol­lows our path, and that would mean mak­ing clear what we our­selves have lost dur­ing the age of air con­di­tion­ing. For exam­ple, with less expo­sure to heat, our bod­ies can fail to accli­ma­tize phys­i­o­log­i­cally to sum­mer con­di­tions, while we develop a men­tal depen­dence on cool­ing. Community cohe­sion also has been rup­tured, as neigh­bor­hoods that on warm sum­mer evenings were once filled with peo­ple min­gling are now silent—save for the whirring of air-conditioning units. A half-century of con­struc­tion on the model of refrig­er­ated cool­ing has left us with homes and offices in which nat­ural ven­ti­la­tion often is either impos­si­ble or inef­fec­tive. The result is that the same cool­ing tech­nol­ogy that can save lives dur­ing brief, intense heat waves is help­ing under­mine our health at most other times.

The time win­dow for debat­ing the ben­e­fits and costs of air con­di­tion­ing on a global scale is narrowing—once a coun­try goes down the air-conditioned path, it is very hard to change course.

China is already sprint­ing for­ward and is expected to sur­pass the United States as the world’s biggest user of elec­tric­ity for air con­di­tion­ing by 2020. Consider this: The num­ber of U.S. homes equipped with air con­di­tion­ing rose from 64 to 100 mil­lion between 1993 and 2009, whereas 50 mil­lion air-conditioning units were sold in China in 2010 alone. And it is pro­jected that the num­ber of air-conditioned vehi­cles in China will reach 100 mil­lion in 2015, hav­ing more than dou­bled in just five years.

As urban China, Japan, and South Korea approach the air-conditioning sat­u­ra­tion point, the great­est demand growth in the post-2020 world is expected to occur else­where, most promi­nently in South and Southeast Asia. India will predominate—already, about 40 per­cent of all elec­tric­ity con­sump­tion in the city of Mumbai goes for air con­di­tion­ing. The Middle East is already heav­ily climate-controlled, but growth is expected to con­tinue there as well. Within 15 years, Saudi Arabia could actu­ally be con­sum­ing more oil than it exports, due largely to air con­di­tion­ing. And with sum­mers warm­ing, the United States and Mexico will con­tinue increas­ing their heavy con­sump­tion of cool.

Countries are already strug­gling to keep up with peak power demand in hot weather. This sum­mer, India is see­ing a short­fall of 17 gigawatts, with res­i­den­tial elec­tric­ity shut off for 16 hours per day in some areas. China is falling short by 30 to 40 gigawatts, result­ing in energy rationing and fac­tory closings.

In most coun­tries, the bulk of elec­tric­ity that runs air con­di­tion­ers in homes and busi­nesses is gen­er­ated from fos­sil fuels, most promi­nently coal. In con­trast, a large share of space heat­ing in cooler cli­mates is done by directly burn­ing fuels—usually nat­ural gas, other gases, or oil, all of which have some­what smaller car­bon emis­sions than coal. That, together with the energy losses involved in gen­er­a­tion and trans­mis­sion of elec­tric power, means that on aver­age, an air con­di­tioner causes more green­house emis­sions when push­ing heat out of a house than does a fur­nace when putting the same quan­tity of heat into a house.

Click here to read the rest of this arti­cle at Yale Environment 360.