The ozone layer is on its way to full recovery from the devastation of the 1980s, but it isn't all good news for the environment.
Chemicals that were successfully banned by countries around the world in the late 1980s after scientists noticed a hole in the atmosphere over Antarctica were replaced by chemicals that are actually fueling global warming, according to scientists. The US is one of a handful of countries now pushing for another iteration of chemicals that won't cause either problem.
The UN released a report Wednesday touting the success of the Montreal Protocol, a 1987 agreement signed by 197 countries to ban the use of ozone-depleting substances. The report announced that the ozone was expected to return to its pre-1980 levels by the middle of this century, and touted the Montreal Protocol as a successful example of what can happen when the world works together to tackle climate problems.
But now the world may have yet another climate problem to face.
The Montreal Protocol banned the use of chlorofluorocarbons, known as CFCs, which are chemicals mainly used in refrigerators, air conditioners, foam insulation, and fire extinguishers. In the 1970s and 1980s, scientists found that CFCs were leaking out of appliances and working their way up toward clouds over the Antarctic, where they would interact with the ozone layer when activated by sunlight and eat away at it, causing the ozone layer to become dangerously thin.
This led to the development of other fluorinated gases as replacements, first HCFCs, another synthetic chemical that was discovered to harm the ozone layer and contribute to global warming, and finally, HFCs, the most recent iteration of the synthetic chemical, which are still problematic.
"[HFCs] barely affect the ozone layer, but they still trap greenhouse gases," Ilissa Ocko of the Environmental Defense Fund told VICE News. "It was a solution that fixed the ozone layer but didn't fix the climate warming aspects of these chemicals, so you're having a lot of benefits seen in the ozone. But we're still adding greenhouse gas trapping to the layer."
Right now, fluorinated gases account for only three percent of the greenhouse gasses that are warming the earth. Carbon dioxide and methane, the two poster-gases for climate change, are responsible for 82 percent and 9 percent of that warming, according to the EPA.
But as China and other developing nations make the switch from HCFCs to HFCs, the problem could grow.The levels of HFCs are increasing by 7 percent each year, and have more than doubled in the past two decades, according to the UN report. By 2050, they could be equivalent to 20 percent of the carbon dioxide in the atmosphere, according to the White House. Their increase could significantly offset the gains of the Montreal Protocol, the report said.
"It has the potential to become a huge contributor in the future if we're not wary of [HFCs]," Ocko said. "It's something that's being flagged as a major problem in the future if we let emissions go unchecked."
"We need to find a replacement for it. It's always about innovating to find the next best chemical to replace them. It's an ongoing process of swapping them out," she said.
Last year, the White House announced that the US and China had reached an agreement that the Montreal Protocol countries should form a working group to figure out how to phase out HFCs.
"Reducing HFCs is an important domestic component of the president's Climate Action Plan," the White House said after the G20 meeting in September 2013, pointing out that it had already created incentives for automakers in the US to move away from using HFCs in car cooling systems. A global phase-out of HFCs could reduce "roughly two years worth of current global greenhouse gas emissions," the White House said.
"A lot of scientists are pushing to have policy changes so we regulate HFCs. It's just a matter of when," Ocko said.
"The major question is whether that is something we need to do today or can we give it five to 10 years, and do it then? It still won't be a major problem for global warming, so, can't we push this off until we have good replacements? But policies take a long time, and so if there's a favorable political climate, it's worth doing now so it kicks in in five years," Ocko said.
The UN report pointed out that even if countries switch to using a new substance, there will be old appliances sitting around emitting HFCs for a long time. These old refrigerators and air conditioning units, known as "banks" of emissions, pose a long-term threat, the report said.
Though the US and China are attempting to take the lead in switching from HFCs to a new substance soon, many developing nations will take years to catch up. They are still trying to make the switch from the last iteration, HCFC, to HFC, Otto said.
"[For] developing countries, how frustrating would it be for them to have to switch again? There's still going to be a lag between when developed and developing countries do this," she said. "It can be hard in developing nations to reach the right places, for the transportation of the new chemicals, the switching out units, a lot of stuff."
Follow Colleen Curry on Twitter: @CurryColleen
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