LIFE SAVER
The United States experience also illustrates how being richer and more technologically advanced can help mitigate temperature risks. In the United States, the estimates of the mortality impacts of high temperatures in the 1920s and 1930s were six times larger than the estimates for the current period.The difference may be entirely due to the much greater access to air conditioning, a key mechanism through which residents of rich countries adapt to higher temperatures.13 This explains why in hot years energy demand goes up massively in rich countries.
In poor countries, where air conditioning is still rare (in 2011, 87 percent of households in the United States had air conditioning, but only 5 percent of Indians did14), we see larger reductions in productivity, and increases in mortality when temperatures go up. In these places, air conditioning could be a critical adaptation tool. It should not be a luxury, but it is.As poor countries become richer, they will be able to afford more air conditioning. Between 1995 and 2009, the ratio of air-conditioning units to homes in urban China went from 8 percent to over 100 percent (meaning there was more than one AC unit per urban household).15 But air conditioning itself aggravates global warming. The hydrofluorocarbon (HFC) gases used in standard air-conditioning appliances have particularly deleterious impacts on the climate; they are much more dangerous than CO2. This puts us in a rather difficult situation. The very technology that can help to protect people from climate change also accelerates the rate of climate change. Newly available air conditioners that do not use HFC pollute less, but at the moment they are much more expensive. A country like India, which is on the cusp of being able to afford the cheaper air-conditioning appliances, thus faces a particularly ghastly trade-off: saving lives today, or moderating climate change to save lives in the future.
An agreement reached in Kigali, Rwanda, in October 2016, after years of negotiation, illustrates how the world navigates this trade-off (when it does manage to navigate it). The Kigali agreement created three tracks: rich countries, including the United States, Japan, and Europe, will start phasing out synthetic HFCs in 2019; China and a hundred other developing countries in 2024; and a small group of countries, including India, Pakistan, and some Gulf States, will postpone the start date until 2028. While realizing its citizens are both the victims and the cause of global warming, the Indian government took the stance that they prefer to save lives today rather than tackle the problem right now. They are probably banking on the fact that economic growth in the intervening years will put them in a position to afford the more expensive devices (which may also have become cheaper in the meantime) by 2028. But during those ten years, there could be a very rapid spread of old-style appliances in India, especially since the makers of the HFC-based machines will want an outlet for their products, and these will stay operational and continue to pollute for years after 2028. This delay could turn out to be quite costly for the planet.