Final answer:
To reduce the average global temperature significantly, deep cuts in greenhouse gas emissions are required. The goal is to reach 'net zero' emissions by 2050. The exact required change in human emissions isn't specified, but substantial reductions, potentially 50-75% or more of 2010 emissions, are indicated as necessary in climate models and agreements to limit warming to safe levels.
Step-by-step explanation:
Human Emissions and Global Temperature Reduction
The Paris Agreement, established during the United Nations conference on climate change in December 2015, highlighted the importance of limiting global warming to less than 2°C above pre-industrial levels, pursuing efforts to limit it even further to 1.5°C. To achieve these targets, deep cuts in greenhouse gas emissions are required. Despite not having a specific percentage in the provided materials, the Union of Concerned Scientists suggests that 'net zero' carbon emissions should be met by 2050 or sooner.
If we continue using fossil fuels at today's levels, the atmospheric CO2 levels would more than double the pre-industrial CO2 levels, suggesting the need for significant and sustainable reductions in emissions. Evaluating the tweaks to human emissions, the scenario of zero emissions is held as a golden standard, though complete eradication of emissions is highly challenging. Realistically, simulations suggest that substantial emission reductions are crucial, potentially within the range of 50-75% or more of 2010 emissions, to keep temperature increases within safe limits.