Managing Activities

**Chapter 4**

*Nizar Jaoua*

**Abstract**

of CO2.

**1. Introduction**

technologies.

**63**

Mathematical Model for CO2

Reverse Global Warming

Emissions Reduction to Slow and

This chapter aims to provide climate policy makers with smooth patterns of global carbon dioxide (CO2) emissions consistent with the UN climate targets. An accessible mathematical approach is used to design such models. First, the global warming is quantified with time to determine when the climate targets will be hit in case of no climate mitigation. Then, the remaining budget for CO2 emissions is derived based on recent data. Considering this for future emissions, first proposed is an exponential model for their rapid reduction and long-term stabilization slightly above zero. Then, suitable interpolations are performed to ensure a smooth and flexible transition to the exponential decline. Compared to UN climate simulation models, the designed smooth pathways would, in the short term, overcome a global lack of no-carbon energy and, in the long term, tolerate low emissions that will almost disappear as soon as desired from the 2040s with no need for direct removal

**Keywords:** atmospheric carbon dioxide (CO2), global CO2 emissions, global warming, remaining CO2 budget, time model, UN climate target

The climate change has been declared as an urgent global threat [1] since the spread of devastating floods, severe droughts, and ravaging wildfires, due to rising temperatures especially in the past three decades [2–4]. In response to this threat, the UN parties adopted the *2015 Paris Agreement on Climate Change* along with its implementation by 2020. Was included 'holding the increase in global annual average temperature above the pre-industrial level well below 2°C and pursuing efforts to limit it to 1.5°C' ([1], Art.2). Was also comprised 'projecting global peaking of greenhouse gases emissions as soon as possible along with their rapid reduction' ([1], Art.4). Since the last century, the atmospheric carbon dioxide (CO2) has been largely dominating the other greenhouse gases [5, 6] due to increasing anthropogenic CO2 emissions as a consequence of a growing global demand for fossil-fuel-based products. Subsequently, climate policies would include a massive reduction of these emissions by shifting to no-carbon energy and introducing gas capture/removal

Climate mathematical modelling has so far focused on the physics behind the global warming, and has therefore described the rise in global average temperature
