The concept of "net zero" has its roots in the scientific community and the growing understanding of the impacts of human activities on the environment, particularly in relation to greenhouse gas emissions and climate change. Here's a brief history of how the term "net zero" emerged:

Early origins: The concept of balancing emissions with removals can be traced back to the late 1980s and early 1990s when scientists began discussing stabilizing atmospheric greenhouse gas concentrations to mitigate climate change. Balancing emmissions and removals was seen as a potential approach to achieving this.

Kyoto Protocol: The 1997 Kyoto Protocol introduced a target for developed countries to reduce their greenhouse gas emissions by an average of 5.2% below 1990 levels by the period 2008-2012. The idea of "net emission reduction" was mentioned in the protocols, though not specifically used in reference to achieving zero emissions.

2005: Stern review: The Stern Review on the economics of climate change, led by economist Nicholas Stern, highlighted the potential costs of climate inaction and emphasized the benefits of taking early action to reduce greenhouse gas emissions.

2007: Intergovernmental Panel on climate change (IPCC). In its forth Assessment Report, the IPCC discussed stabilization pathways that would likely lead to a "very low stabilization scenario," where global warming would be limited to 2 degrees Celsius above pre-industrial levels. The report noted the implications for achieving zero net emissions over the long term.

2015: Paris Agreement: A key turning point came with the adoption of the Paris Agreement in 2015. Nations committed to pursuing efforts to limit global warming to 1.5 degrees above pre-industrial levels. The agreement included a long term goal to balance anthropogenic emissions by sources and removal by sinks, recognizing the concept of net zero emissions.

Net Zero by 2050: In recent years, the concept of achieving net zero emissions by 2050 has gained significant momentum. Many countries, states, cities and organizations have set net-zero targets, emphasizing the urgency of transitioning to low carbon economies.

The term "net zero" has become a widely recognized and important concept in climate discussions, underscoring the need for transformative changes in energy systems, industries, and lifestyles to limit global temperature rise and mitigate the consequences of climate change.