It’s been reported that HFCs are several thousand times more potent than carbon dioxide. That’s true, but there’s very, very little of them in the atmosphere.
Air-conditioners are everywhere – but how much HFCs are there in the atmosphere? Credit: Pēteris/Flickr, CC BY 2.0
An agreement to limit the future use of hydrofluorocarbons – or HFCs, chemical refrigerants used in ACs, fridges and cars, and which contribute to global warming – has just been inked in Rwanda’s capital Kigali. It’s been agreed that HFC manufacture and use will peak in three phases: Much of the industrialised first world will do so by 2018, China, Brazil and Africa by 2024; and India, Pakistan and many others by 2028. And over the years, its production and use will be made to decline to 15-20% of an agreed peak, with a different timeframe for each of these three country groupings. In India, we will have to reduce its use to one-seventh our 2025 levels by 2047. They will be replaced by other refrigerants that are less harmful climatically.
The Kigali agreement has been met with rapturous welcome. The New York Times waxed lyrical that “the outcome could have an equal or even greater impact [than the Paris Agreement] on efforts to slow the heating of the planet.” The US Secretary of State John Kerry has been quoted as saying, “It is likely the single most important step we could take at this moment to limit the warming of our planet.” At the same time, some relevant data published by the Intergovernmental Panel on Climate Change (IPCC) suggests we need to keep our excitement in check.
A key concept to quantify and understand the warming caused by any agent is its radiative forcing (RF). Radiative forcing is the planetary energy imbalance caused by changes in any driver, either human (greenhouse gases such as carbon dioxide, methane, HFCs, etc., added to the atmosphere) or natural (changes in the Sun’s luminosity, e.g.). RF is measured in watts per square metre (W/m^-2). An increase in the radiative forcing of every one watt per square metre results, eventually, in a warming of 0.75º C over the long-term.
The IPCC’s Fifth Assessment Report provides a handy table of the radiative forcings of different greenhouse gases over the period 1750-2011. The main greenhouse gas, carbon dioxide, has caused a radiative forcing of 1.82 watts/m^-2; methane’s contribution is 0.97. In contrast, the HFCs have had a forcing of merely 0.02 W. Include HCFCs as well, and they total 0.07 watts, 26-times less than carbon dioxide’s.
Okay, so HFCs weren’t around in 1750, so some may think it’s an unfair comparison. But if one were to compare these latest numbers with that in the previous IPCC report of 2007, the radiative forcing of HFCs rose from 0.01 to 0.02 W between 2005 and 2011. If one takes HCFC-22, a refrigerant commonly used in India, its forcing rose from 0.03 to 0.04 watts in the same period. In comparison, CO2’s RF increased by 0.16 watts over the same six-year period. It’s been reported that HFCs are several thousand times more potent than carbon dioxide. That’s true, but there’s very, very little of them in the atmosphere.
The agreement has been welcomed because it would slow down what many fear would be an exponential rise in this trace greenhouse gas what with the increased use of refrigerators, ACs and cars in China and India in the years to come. But the numbers above suggest that an increase in its RF to even ten times as much as the present would be small compared to the increase in carbon dioxide’s or methane’s warming effects. This isn’t to pour cold water over the Kigali agreement – but let’s maintain a little perspective.
There is a broader issue here that relates to our development trajectory. It’s a reflection of our partial, skewed approach to tackling global warming: that we seek to minimise refrigerants and coolants but not the gadgets that need them in the first place, whose greenhouse gas emissions through their making and operating are vastly greater. Take, say, home air-ACs. The window AC units you’d have in your homes require 900-1,400 W. A colleague in India Climate Justice conducts workshops in colleges and elsewhere to measure a household’s carbon footprint. In one such workshop, we found that a household using an AC for a few hours each day emits over 800 kg of carbon dioxide in a year from the AC alone!
A mindset that focuses on HFCs but has nothing to say about the massive electricity demanded by AC use is not one that will help us in tackling global warming. There have been opinions lamenting what this agreement may imply for future potential users of personal ACs in India, because substituting HFCs may make ACs more expensive. In a country where, going by official figures, over 300 million people – including 25 million in urban areas – have no access to any electricity at all, and perhaps another 300 million do for only a few hours each day, it isn’t clear that our chief concern ought to be that more people will not use ACs at home.
There’s also the issue of carbon emissions embodied in the manufacturing of these consumer goods, which again are much greater than emissions from HFCs. Take just one part of the embodied emissions that go into making a car. According to the Aluminium Association of India’s website, any car made in India contains, on average, about 140 kg of aluminium. Manufacturing aluminium is hugely energy intensive. According to the International Energy Association, it takes roughly 15 megawatt-hours’ worth of electricity to manufacture each tonne of aluminium from alumina because the process needs so much heat.
And the energy needed in the entire process – from mining the bauxite ore, transforming it into alumina and thence to aluminium – would require at least 25 megawatt-hours per tonne of aluminium, though some sources peg it higher. Given that generating each megawatt-hour of electricity emits about a thousand kg of carbon dioxide in India and about 750 kg worldwide, that’s a staggering 19,000-25,000 kg of carbon dioxide in manufacturing every tonne of aluminium. Do the math for the 140 kg in an average car, and one arrives at about 2,800-3,500 kg of carbon dioxide trapped just in the aluminium in the car.
To say nothing of everything else that goes into making the car. And we are concerned about the HFCs from its AC unit alone?
Focusing on technology while ignoring its trajectory is a grave, wilfully blinkered omission. To be sure, the deal in Kigali is welcome for climate reasons; but, for those very reasons, it is worrying that burning fossil fuels is still so firmly part of the world’s future energy basket. BP’s study of future energy trends worldwide published last year says, “Fossil fuels [will] remain the dominant form of [primary] energy in 2035, with a share of 81%.” The Paris Agreement, as it currently stands, will take us to at least 3º C of warming, way beyond dangerous levels. In climate terms, the Kigali agreement is a small, half-step forward.
Unless we are less easily satisfied, unless we are able to push a lot harder, our development trajectory – increasingly unequal and unsustainable, both in India and around the world – will at the same time be pushing us two large steps back, taking the planet to levels of warming not experienced ever before in human history.
Nagraj Adve is a member of India Climate Justice. He works and writes on issues related to global warming.
