This Strategy Reduces Emissions Of Climate Pollutants To Cut Global Warming Rate In Half: Study

The new study states that a strategy that simultaneously reduces emissions of largely neglected climate pollutants other than carbon-dioxide would cut the rate of global warming in half.

New Delhi: Reducing carbon-dioxide emissions alone is not enough to prevent catastrophic global warming. However, a new study states that a strategy that simultaneously reduces emissions of other largely neglected climate pollutants would cut the rate of global warming in half, giving the world a fighting chance to keep the climate safe for humanity. 

The study was recently published in the journal Proceedings of the National Academy Sciences. 

How Is The Study Unique?

It is the first study to analyse the importance of slashing non-carbon dioxide climate pollutants by merely reducing fossil fuel emissions, in both the near-term and mid-term to 2050. 

There are fears that the present almost exclusive focus on carbon-dioxide cannot by itself prevent global temperatures from exceeding 1.5 degrees Celsius above pre-industrial levels, which is the international limit beyond which the world's climate is expected to pass irreversible tipping points. The study confirms these fears.

Decarbonisation alone is unlikely to prevent temperatures from exceeding even the two degrees Celsius limit. The study was conducted by scientists at Georgetown University, Texas A&M University, Scripps Institution of Oceanography at the University of California San Diego, and others. 

What Dual Strategy Must Be Adopted?

Adopting a dual strategy that simultaneously reduces emissions of both carbon-dioxide and the other climate pollutants would cut the rate of warming in half by 2050, the study concludes. This would make it much easier to stay within these limits.

What Are The Different Non-Carbon Pollutants?

The different non-carbon dioxide pollutants are: methane, hydrofluorocarbon refrigerants, black carbon soot, ground-level ozone smog, and nitrous oxide. According to the study, together these pollutants currently contribute almost as much to global warming as carbon-dioxide. Most of these pollutants last only a short time in the atmosphere. Hence, cutting them slows warming faster than any other mitigation strategy. Until now, scientists and policymakers have underappreciated the importance of these non-carbon dioxide pollutants. 

What Do Recent IPCC Reports Conclude?

According to recent reports by the Intergovernmental Panel on Climate Change (IPCC), cutting fossil fuel emissions, the main source of carbon-dioxide, by decarbonising the energy system and shifting to clean energy, in isolation, actually makes global warming worse in the short term. This happens because burning fossil fuels also emits sulphate aerosols, which act to cool the climate. Switching to clean energy reduces sulphate aerosols along with carbon-dioxide. Within days to weeks, the cooling sulphates fall out of the atmosphere. However, much of the carbon-dioxide lasts hundreds of years, which leads to overall warming for the first decade or two.

What Happens When One Focuses Exclusively On Reducing Fossil Fuel Emissions?

In the new study, the researchers account for this effect and conclude that focusing exclusively on reducing fossil fuel emissions could result in "weak, near-term warming" which could potentially cause temperatures to exceed the 1.5 degrees Celsius level by 2035 and the two degrees Celsius level by 2050. 

How Is The Dual Strategy Beneficial?

Meanwhile, the dual strategy simultaneously reduces the non-carbon dioxide pollutants, especially the short-lived pollutants, which would enable the world to stay well below 1.5 degrees Celsius. A key insight from the study is the need for climate policies to address all of the pollutants emitted from fossil fuel sources such as coal power plants and diesel engines rather than considering just carbon-dioxide or methane individually. 

The study emphasises that continuing to slash fossil fuel carbon-dioxide emissions remain vital. Climate will be in danger in the longer term beyond 2050, if fossil fuel emissions are not controlled. 

Fossil fuels produce air pollution that kills over eight million people every year and causes billions of dollars of damage to crops. This is another reason why phasing out fossil fuels is essential.

According to the study, the best and only hope of humanity to make it to 2050 without triggering irreversible and potentially catastrophic climate change is tackling both carbon-dioxide and the short-lived pollutants at the same time.