The Paris climate agreement has long been seen as a great hope in the fight against climate change. But the temporary departure of the United States under Donald Trump scratched this image. A working paper now shows the serious consequences it would have if individual countries with high greenhouse gas emissions, such as the USA or China, gave up permanently. Global emissions would fall noticeably less as a result, undoing the hard work of other countries.
When the Paris climate agreement was adopted in 2015, it raised hopes around the world that we could face climate change as a cohesive global community. In order to keep global warming well below two degrees, 195 countries pledged to reduce their greenhouse gas emissions. However, at the latest when the United States temporarily withdrew under Donald Trump in 2020 and only intervened again under Joe Biden, the agreement of the contracting parties threatened to crumble. In addition, only very few countries have planned sufficient emission reductions to achieve the Paris climate protection target.
Drastic consequences of the withdrawal of the largest issuers
Appropriate for the beginning of the current world climate summit COP27 in Sharm el-Sheikh, a report by the UN environment program UNEP gave the climate protection efforts of the countries a bad report. The national self-commitments submitted so far will therefore only reduce global emissions by five to ten percent by 2030. In order to achieve the climate target of the Paris Agreement, however, a reduction of 30 to 45 percent would be necessary.
In a working paper, Mario Larch from the University of Bayreuth and Joschka Wanner from the Kiel Institute for the World Economy (IfW) also examined the potential consequences of individual countries withdrawing from the Paris Climate Agreement. To do this, they determined what effect this country's exit would have on global emissions and on the achievement of the Paris climate protection target. In the 140 analyzed scenarios, the USA and China stand out the most.
According to the researchers, an exit by the USA would have the most dramatic consequences. “The United States is the second largest emitter in the world. However, they have also committed themselves to a significant reduction in their emissions with a targeted reduction of 47 percent,” says Wanner. An exit by the USA would mean that this enormous saving in emissions would simply fizzle out. From a global perspective, emissions would then no longer fall by 25.4 percent by 2030, but only by 17.3 percent. If China pulled out, global CO2 emissions would fall by 22.5 percent. According to researchers, China is the world's largest emitter, but has set itself less ambitious climate targets than the USA, only an emission reduction of 11.3 percent.
Emissions could even increase
But that's not all: "Individual countries that withdraw from the Paris climate agreement have an incentive to even increase their emissions," explains Wanner. Since they no longer have to limit their greenhouse gas emissions, while other countries do, this gives them a competitive advantage in economic sectors that emit particularly large amounts of emissions. On the other hand, fossil fuel prices would fall globally as other countries switch to more climate-friendly alternatives. That would be a further incentive for countries outside the agreement to focus more on fossil fuels.
Larch and Wanner calculated that an American exit from the climate agreement would result in that country's emissions increasing by 9.5 percent, and in China it would be as much as 14 percent. If you add this to the emissions reductions originally promised but no longer fulfilled by the exit, this would mean that global emissions would fall by only 15.7 percent instead of 25.4 percent if the US exited. If China exited, it would be 19.3 percent. According to researchers, this would negate the climate efforts of other countries.
However, these model calculations are initially only hypothetical, because an actual exit of the two countries is currently not imminent. But they show that all countries must work together to tackle climate change, and that misfits jeopardize everyone's efforts. According to the researchers, this also applies if a country does not officially withdraw but still does not fulfill its promised goals.
Source: Kiel Institute for the World Economy; Specialist article: Kiel Working Paper