IPCC global warming report: why air conditioning rises 30-fold by 2100

Warming climates and rising incomes will lead to a surge in cooling-related energy use, according to the latest report by the Intergovernmental Panel on Climate Change. It's one of several ways global warming is set to alter global energy supply and demand.

It's a good era to be in air conditioner sales. 

Warming climates and especially the rise of a global middle class are going to send new populations in search of artificial cooling. That's one conclusion of an expansive new report issued Monday by the Intergovernmental Panel on Climate Change (IPCC), a United Nations scientific panel that periodically reviews the scientific basis for climate change.

The impacts and vulnerabilities associated with climate change "are already occurring on all continents and across the oceans," according to the report, but governments, companies, and communities are implementing plans to adapt to warming climates, rising sea levels, and changes in precipitation. 

“Understanding that climate change is a challenge in managing risk opens a wide range of opportunities for integrating adaptation with economic and social development and with initiatives to limit future warming," Chris Field, co-chair of the group responsible for Monday's report, said in a statement. "We definitely face challenges, but understanding those challenges and tackling them creatively can make climate-change adaptation an important way to help build a more vibrant world in the near-term and beyond.”   

One challenge? Energy demand for residential air conditioning in summer is projected to increase more than 30-fold: from nearly 300 terawatt-hours (TWh) in 2000 to about 4,000 TWh in 2050 and more than 10,000 TWh in 2100, according to the report. Growing middle classes in emerging markets accounts for three quarters of that increase, with the rest resulting from climate change. The uptick in artificial cooling – itself a major source of greenhouse gases – underscores energy's role as both cause and effect of climate change.

The global energy supply generates much of the heat-trapping gases that have contributed to a rise in Earth’s average surface air temperature over the past century. And energy is vulnerable to the resulting warming climates, rising seas, and prolonged dry spells scientists say will continue to destabilize regions of the world. That changing climate is likely to increase electricity demand in most parts of the world (largely due to increased air conditioner use) while decreasing the efficiency of most forms of power generation, according to the IPCC report, the second in a series of three.

Not all of it is bad news. Heating demand decreases for developed countries in colder climates as winters get warmer. In most parts of the world, increased rainfall slightly boosts power production from hydroelectric dams, according to the IPCC report, and higher average temperatures increase the transmission efficiency of power lines. But taken as a whole, the potential negative impacts of climate change on global energy supply outweigh the benefits, the report concludes.

"Earlier IPCC assessments did not write much about energy supply, but an increasing number of studies now explore its vulnerability, impacts and the adaptation options," the report reads. "The energy sector will be transformed by climate policy ... but impacts of climate changes too will be important for secure and reliable energy supply."

Thermal power plants, which provide about 80 percent of global electricity, are less efficient in higher temperatures and are more difficult to keep cool when local water supplies heat or dry up. Water is particularly important in nuclear power, where it is used as a coolant to prevent meltdowns. Extreme weather and hotter climates pose significant threats to the extraction and distribution of energy resources, the report finds. Floods, droughts, wildfires, and storms have already shut down oil rigs, knock down power lines, constrain pipelines, and cause other costly infrastructure damage – a trend that will continue.

Some have criticized the report as exaggerating the negative consequences of climate change while minimizing the benefits. Richard Tol, a Dutch professor of economics and one of the report's 70 authors, pulled out of the writing team last week saying the report had become too "alarmist." Mr. Field defended the group's findings in an interview with the Financial Times Monday.

“When the IPCC does a report, what you get is the community’s position," Field said. "Richard Tol is a wonderful scientist but he’s not at the centre of the thinking. He’s kind of out on the fringe."