I can provide information on the context . The target of limiting global warming to 1.5 degrees Celsius above pre-industrial levels was established by the Paris Agreement, an international treaty adopted in 2015. The agreement aimed to strengthen the global response to climate change and set various goals to mitigate its impacts.
The decision to include the 1.5 degrees Celsius target in the Paris Agreement was based on scientific evidence and concerns about the severe consequences of allowing global temperatures to rise beyond that level. The Intergovernmental Panel on Climate Change (IPCC) conducted an extensive assessment of the impacts of global warming and found that limiting the temperature increase to 1.5 degrees Celsius would significantly reduce the risks associated with climate change compared to a 2 degrees Celsius increase.
The shift from a 2 degrees Celsius target to a 1.5 degrees Celsius target recognizes the urgency of addressing climate change and the need for more ambitious action. Limiting global warming to 1.5 degrees Celsius requires more substantial emissions reductions and greater efforts to transition to renewable energy sources, improve energy efficiency, and implement sustainable practices across various sectors.
If there have been any significant developments or changes regarding global warming targets since I'm not interested in that topic as much as i used to and my answer might be a bit outdated, I recommend referring to the latest scientific reports, international agreements, and reputable news sources for up-to-date information.