New study explains how to broaden strategy to avert catastrophic climate change

Slashing emissions of carbon dioxide can't prevent global warming. A new study concludes that a strategy that reduces emissions of other climate pollutants would cut the rate of global warming in half and give the world a fighting chance to keep the climate safe for humanity.

The study is the first to analyze the importance of cutting non-carbon dioxide climate pollutants vis--vis merely reducing fossil fuel emissions, in both the near-term and mid-term to 2050. It confirms that the focus on carbon dioxide alone cannot prevent global temperatures from rising to 1.5 degrees Celsius above pre-industrial levels, the internationally accepted guardrail beyond which the world's climate is expected to pass irreversible tipping points.

Decarbonization alone wouldn't stop temperatures from exceeding the 2 degrees Celsius limit.

A study by scientists at Georgetown University, Texas A&M University, and others shows that a dual strategy that reduces emissions of both carbon dioxide and the other climate pollutants would cut emissions.

The non-carbon dioxide pollutants include methane, hydrofluorocarbons, black carbon soot, ground-level ozone smog, and nitrous oxide. According to the study, these pollutants contribute almost as much to global warming as carbon dioxide. Since most of them last only a short time in the atmosphere, cutting them slows warming more quickly than any other strategy.

The importance of non-carbon dioxide pollutants has been neglected in efforts to combat climate change.

According to recent reports by the Intergovernmental Panel on Climate Change, cutting fossil fuel emissions by decarbonizing the energy system and shifting to clean energy makes global warming worse in the short term. When you switch to clean energy, sulfate aerosols are reduced along with the carbon dioxide because they act to cool the climate. The cooling sulfates fall out of the atmosphere fast, within days to weeks, while carbon dioxide lasts hundreds of years, thus leading to overall warming for the first decade or two.

The new study shows that if we focus exclusively on reducing fossil fuel emissions, it will cause a weak, near-term warming which could cause temperatures to exceed the 1.5 degrees Celsius level by 2035 and the 2 degrees Celsius level by 2050.

The dual strategy that reduces the non-carbon dioxide pollutants and the short-lived pollutants simultaneously would allow the world to stay well below the 2 degrees Celsius limit.

The need for climate policies to address all of the pollutants that are emitted from fossil fuel sources such as coal power plants and diesel engines is a key insight from the study.

The study emphasizes that cutting fossil fuel carbon dioxide emissions will determine the fate of the climate in the long term. Fossil fuels cause air pollution that kills eight million people every year and causes billions of dollars of damage to crops.

Tackling both carbon dioxide and the short-lived pollutants at the same time offers the best and only hope of humanity making it to 2050 without triggering irreversible and potentially catastrophic climate change.

More information: Gabrielle B. Dreyfus et al, Mitigating Climate Disruption in Time: A self-consistent approach for avoiding both near-term and long-term global warming, Proceedings of the National Academy of Sciences (2022). DOI: 10.1073/pnas.2123536119 Journal information: Proceedings of the National Academy of Sciences Citation: New study explains how to broaden strategy to avert catastrophic climate change (2022, May 23) retrieved 23 May 2022 from https://phys.org/news/2022-05-broaden-strategy-avert-catastrophic-climate.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.