To stop global warming, it is not enough to reduce CO2 emissions
It is NOT enough to reduce carbon dioxide emissions in order to stop climate change, but it is also necessary to act on lesser-known pollutants, such as nitrogen oxide, which also play a key role in global warming, a study has shown.
Discussions about climate change have been focused for decades on CO2 emissions, which are the most abundant in the atmosphere. The common goal of many countries – achieving a zero emission rate – therefore mostly refers only to CO2.
Over the past year, more than 100 countries have committed to reducing methane emissions by 30 percent by 2030, another carbon-based greenhouse gas that has a significantly greater warming effect than CO2.
The EU plans to reduce harmful emissions by at least 55 percent by 2030
In April this year, the European Parliament supported the revision of the greenhouse gas emissions trading system (ETS) in order for the EU to better control the amount of emitted harmful gases and reduce them by 55 percent by 2030.
But this revision also primarily refers to CO2 and methane emissions. The revision is otherwise a key part of the “Fit for 55” plan by which the EU plans to reduce harmful emissions by at least 55 percent compared to 1990 levels by 2030.
However, most countries that have announced their plans to reduce harmful emissions have not yet announced how exactly they will achieve this goal.
A study whose results were published this week in the journal Proceedings of the National Academy of Sciences (PNAS) warns that too little attention is being paid to other pollutants that cause global warming.
Among them are black carbon, or soot, which absorbs thermal radiation, then fluorocarbons used in cooling devices, and nitrogen oxide.
Along with methane, these pollutants contribute about 50 percent to global warming, the study found.
“We have to pay attention to other climate factors, not only CO2”
“We need to pay attention to other climate factors, not just CO2,” warned one of the authors of the study, Durwood Zaelke, president of the Institute for Governance and Sustainable Development in Washington.
This is especially important as countries try to reduce CO2 emissions by reducing the use of fossil fuels, which are still considered the main culprits of global warming.
Fewer fossil fuels mean less air pollution, among other things fewer sulfates that are carried by air and that even neutralize some climate changes because they reflect solar radiation from the Earth, according to scientists.
They add that because of these sulfates, warming appears to be less by about half a degree Celsius. In other words, the warming appears to be half a Celsius higher than it currently neon appears. This means that stronger climate action could, paradoxically, cause a temporary increase in temperatures.
Unless the profession no longer deals with less common pollutants.
The study also found that if decarbonization continues as planned, this alone would cause Earth’s temperature to rise by two degrees Celsius above pre-industrial levels by 2045.
On the other hand, reining in all harmful emissions and pollutants could see warming start to slow as early as 2030 and the rate of warming halved between 2030 and 2050.
“This work, which serves as a landmark, should be an occasion to rethink global climate goals,” believes scientist Euan Nisbet from London’s Royal Holloway University. Nisbet was otherwise not involved in the study published by PNAS.
“If we don’t reduce pollutants other than CO2, we’re going to cook,” Nisbet said.