Carbon dioxide may be the well-known gas that contributes the largest to the planet’s global warming, but there are other less known gases such asHydrofluorocarbons (HFCs), chlorofluorocarbons (CFCs), nitrous oxide, etc. that are equally dangerous for the earth’s climate. Such gases, particularly HFCs may be emitted in far lesser quantities as compared to carbon dioxide, but they have a huge potential of contributing towards climate change. The threat that these gases pose on climate stability varies based on different factors such as their prevalence in the atmosphere and their greenhouse warming potential. However, curbing the emission of such gases is the key to reduce the impact of man-made climate change. Earlier, climate change discussions and negotiations only focussed on the reduction of carbon dioxide emissions in the atmosphere to reduce the impact of man-made climate change. But presently, discussions are going on to reduce the emissions of other harmful gases as well, and these include the HFCs. They are most commonly used as refrigerants and as aerosol propellants. Presently, HFCs hold a share of only two percent of the total carbon dioxide equivalent emissions, but this may increase up to 20 percent if we continue to use HFCs at the pace that we are using them today. To gauge the effect of HFCs on climate change, it may be noted that a reduction of HFC emissions can reduce 100 gigatons of carbon dioxide equivalent emissions by the year 2050. In addition, a reduction in the emissions of HFCs can prevent a global temperature increase of 0.5 degree Celsius by 2100, studies have indicated. About time we woke up!
The Montreal Protocol
Some countries are already taking action. Countries such as the United States, Canada and Mexico have already placed mechanisms for a reduction in the emission of HFCs by making an amendment to the Montreal Protocol. In addition, more than 100 countries have supported this amendment. While the mechanism to reduce HFC emissions is yet to be adopted globally, several countries have voluntarily started to curb the use and emission of HFCs. Last year in June, United States and China reached an agreement to reduce the emissions of HFC. This is important in the context that United States is the largest consumer of HFCs and China is the main source where such gases are produced. This agreement is an important step in reducing the United States greenhouse gas emissions by 17 percent by the year 2020.
HFCs are also termed as short-lived climate forcers, and while their atmospheric life may be short term, their potential to contribute to global warming is quite high.The threat level of any gas is identified by its global warming potential (GWP), a measure of how much heat a gas can trap in the atmosphere. The GWP of any substance or gas is measured with reference to carbon dioxide, which has a GWP standardised as one. This global warming potential is expressed over a 100 year timescale. With such a frame of reference, it should be noted that several gases have much higher GWP than carbon dioxide. For example, the infamous CFCs or chlorofluorocarbons, emissions of which caused a hole in the ozone layer and were subsequently banned, have a GWP in thousands! This indicates that even a minute emission of CFCs can impact the climate in a huge manner.
According to a study conducted by the US Environmental Protection Agency or the EPA, HFCs have a global warming potential ranging from 140 to 11,700. Hence, a reduction in the emissions of HFCs will create a positive impact on the fight against man-made climate change. Also, considering the fact that HFCs don’t remain in the atmosphere for a long period of time before they are absorbed by a sink such as forests or oceans or being converted into some other substance, a reduction in the emissions of CFCs will have a positive impact on the climate change in a very short period.While it is in the interest of everyone to ban and ultimately stop the production of HFC gases, a broad based agreement needs to be forged for this to take effect. While differences between the developing and developed countries persist on how to tackle climate change and the quantum of reduction of greenhouse gas emissions, the benefits of reduction in the emission of HFCs are clear and the agreement between China and the United States in this regard is a welcome step in the fight against climate change.