During the research, published in Science, the team assessed 35 net zero targets, covering every country with more than 0.1% of current global greenhouse gas emissions. 90 percent of the regions and countries, including China and the United States, need to reconsider their plans due to the low likelihood their policies will be fully implemented, the team found. Exceptions include the European Union, the United Kingdom and New Zealand, which scored high in terms of credibility.
From this assessment, the team modelled five scenarios of future greenhouse gas emissions and resulting temperatures. In the most optimistic scenario, where all targets are implemented, temperatures are expected to rise between 1.6 and 2.1 degrees Celsius. In this case, the Paris goal to limit global warming to well below 2 degrees remains within reach. However, the researchers describe this scenario as “wishful thinking”, as the majority of the current policies are too limited and therefore lack credibility. Furthermore, in the scenario where only existing policies are implemented, temperatures are expected to rise between 1.7 and 3 degrees.
All in all, “the world is still on a risky climate track”, concludes Den Elzen, professor of International Climate Policy and Mitigation of Climate Change at the Institute for Environmental Studies (IVM).