This strategy reduces emissions of climate pollutants to halve the rate of global warming

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

The study has just been published in the journal Proceedings of the National Academy of Sciences.

How is the study unique?

This is the first study to analyze the importance of reducing climate pollutants other than carbon dioxide simply by reducing fossil fuel emissions, both in the short and medium term to 2050.

Some fear that the current almost exclusive focus on carbon dioxide alone could prevent global temperatures from exceeding 1.5 degrees Celsius above pre-industrial levels, which is the international limit beyond which the global climate is expected cross irreversible tipping points. The study confirms these fears.

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

Which double strategy to adopt?

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

What are the different non-carbon pollutants?

The various pollutants other than carbon dioxide are: methane, hydrofluorocarbon refrigerants, black carbon soot, ground-level ozone smog and nitrous oxide. According to the study, these pollutants currently contribute almost as much to global warming as carbon dioxide. Most of these pollutants only stay in the atmosphere for a short time. Therefore, cutting them off slows warming faster than any other mitigation strategy. Until now, scientists and policy makers have underestimated the importance of these pollutants other than carbon dioxide.

What do recent IPCC reports conclude?

According to recent reports by the Intergovernmental Panel on Climate Change (IPCC), reducing emissions of fossil fuels, the main source of carbon dioxide, by decarbonizing the energy system and switching to clean energy, in isolation , actually worsens short-term global warming. term. This happens because burning fossil fuels also emits sulfate aerosols, which act to cool the climate. Switching to clean energy reduces sulfate aerosols as well as carbon dioxide. Within days to weeks, the cooling sulfates drop from the atmosphere. However, much of the carbon dioxide lasts for hundreds of years, leading to global warming for the first one or two decades.

What happens when we focus exclusively on reducing fossil fuel emissions?

In the new study, the researchers take this effect into account and conclude that focusing exclusively on reducing fossil fuel emissions could lead to “near-term weak warming” that could potentially cause temperatures to rise above the level of 1. .5 degrees Celsius by 2035 and the two degrees Celsius level by 2050.

How is the dual strategy beneficial?

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

The study underscores that further reduction of carbon dioxide emissions from fossil fuels remains vital. The climate will be in longer term danger beyond 2050 if fossil fuel emissions are not controlled.

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

According to the study, humanity’s best and only hope of reaching 2050 without triggering irreversible and potentially catastrophic climate change is to tackle both carbon dioxide and short-lived pollutants.

Teresa H. Sadler