Thursday, 3 November 2016

Air-conditioning treath and HFCs extremely powerful heat-trappers

Ozone layer gmt de
Ozone layer gmt de (Photo credit: Wikipedia)
One day the West had thought to have found the solution against an escalating threat to the climate and were pleased to change the refrigerators gases with hydrofluorocarbons (HFCs) to save the ozone layer.

So when nations signed the Montreal Protocol in 1987 – which aimed to save the ozone layer by banning ozone-eating chlorofluorocarbons (CFCs) from use in aerosols, refrigerators and air-conditioning units – few questioned the idea that ozone-friendly hydrofluorocarbons (HFCs) would make a great substitute.

But although HFCs did not destroy the ozone layer, they were potent greenhouse gases.
After almost 30 years, and with the manufacture of HFCs rising globally by 7 per cent each year, that mistake is about to be put right.

Seven years and requiring many determined advocates — major Western governments, the small island nation of Micronesia, poor African nations that fear drought and even starvation and persistent environmental groups reached an accord in Kigali, Rwanda, in October following the ratification by enough countries of last year’s Paris agreement broadly reducing greenhouse gases to allow it to take effect, as well as a narrower agreement to limit emissions from aircraft. It completes a trifecta of diplomatic accords aimed at keeping the rise in global temperatures below 3.6 degrees Fahrenheit (two degrees Celsius) over the average preindustrial temperatures — a point beyond which the manifest consequences of climate change, including rising sea levels and droughts, are likely to become exponentially worse.

Despite obvious threats to their populations from rising sea levels and droughts, some developing countries like India pushed back hard, in part because their people were on the verge of being able to afford air-conditioners powered by HFCs.
Although they now make up only a small part of the greenhouse gases in the atmosphere, HFCs are extremely powerful heat-trappers and, if left unchecked, would make it hard not to exceed the 3.6 degree threshold. One factor driving the negotiations was the rapid growth of air-conditioning in nations like China and India.

HFCs were once seen as a technological godsend. They were developed in response to the 1987 Montreal Protocol, a global agreement requiring nations and manufacturers to find a substitute for chlorofluorocarbons, or CFCs, then the dominant refrigerant, which was destroying the planet’s ozone layer. The chemical industry replaced that chemical with HFCs, which don’t harm the ozone layer but, as it turned out, added greatly to global warming.

The richest countries, including the United States, will freeze production and consumption of HFCs by 2018; much of the rest of the world, including China, Brazil and all of Africa, will do the same by 2024; and a few nations, including India, will have until 2028. Several newer and less harmful refrigerants are available, although they may be more expensive in the short run. The timetable will allow poorer countries to wait until prices come down. But unlike the Paris agreement, which consists of voluntary pledges, this one will be mandatory, with trade sanctions for nations that do not comply.

Mattlan Zackhras, the minister-in-assistance to the president of the Marshall Islands, said in a statement
"It may not be entirely what the islands wanted, but it is a good deal," 
and expressed his hope
"We all know we must go further, and we will go further."
Erik Solheim, executive director of the UN Environment Program, said
"This is about much more than the ozone layer and HFCs. It is a clear statement by all world leaders that the green transformation started in Paris is irreversible and unstoppable."
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