To protect the climate from unwanted changes, in addition to carbon dioxide, emissions of other gases such as methane and ozone must also be reduced, say scientists. Otherwise, the goals cannot be achieved.
According to a new study prepared by a team of scientists from the American Duke University, limiting CO2 emissions into the atmosphere will not be enough to limit global warming to the extent assumed.
If, on the other hand, emissions of other, often overlooked pollutants were also reduced, the rate of warming could be halved. This would give us a chance to ‘win’.
The analysis, presented in the journal Proceedings of the National Academy of Sciences, is, according to its authors, the first to include a comparison of the impact of a wide range of pollutants and the impact of CO2 alone for a possible situation in 2050.
“Decarbonisation is crucial to achieving long-term climate goals, but it is not enough,” – says Professor Drew Shindell, one of the paper’s authors. – “In order to slow warming in the short term and reduce the suffering of societies caused by increasing heat waves, droughts, powerful storms and fires, we need to reduce the presence of also short-lived pollutants in the atmosphere in this decade.”
According to him and his colleagues, focusing only on CO2 – as most governments are doing – will not be enough to reduce warming to less than 1.5 degrees C above pre-industrial temperatures by 2035. Such an increase in temperature implies a high probability of passing various tipping points, after which irreversible changes will begin.
What’s more, with carbon reduction alone, warming could reach as much as 2 degrees C by 2050.
“Our analysis shows that climate-affecting chemicals such as methane, nitrogen oxide, atmospheric soot, low-latitude ozone and hydrofluorocarbons contribute to warming almost as much as long +lived+ carbon dioxide. Since most of these substances in the atmosphere break down quickly, reducing their emissions will slow warming faster than any other strategy,” – says Prof. Shindell.
This approach is expected to protect the Earth from the rapid climate reversal that experts from the Intergovernmental Panel on Climate Change (IPCC) are warning about.
According to their forecasts, the mere abandonment of coal-based methods of energy production could paradoxically raise temperatures in the short term. This is because, in addition to CO2, burning fossil fuels emits sulphur-containing aerosols, which cool the climate. According to researchers at Duke University, broader action is therefore required for a variety of reasons.