Net zero emissions represent a state where the amount of greenhouse gases released into the atmosphere is precisely balanced by the amount removed. This balance is a central goal for addressing climate change and its impacts on the planet. Achieving net zero means that human activities no longer contribute to an increase in atmospheric greenhouse gas concentrations, which is a necessary step to stabilize global temperatures.
The Core Concept of Balancing Emissions
The concept of balancing emissions involves managing both the sources that release greenhouse gases and the sinks that remove them. Emissions come from various human activities, including industrial processes, power generation, transportation, and agriculture. To achieve net zero, these emissions must be reduced as much as possible, with any unavoidable residual emissions then actively removed from the atmosphere.
Net zero encompasses all major greenhouse gases, not just carbon dioxide (CO2). Methane (CH4), nitrous oxide (N2O), and fluorinated gases (F-gases) are also significant contributors to global warming. Methane, for example, has a global warming potential significantly higher than CO2, and nitrous oxide is nearly 300 times more potent than CO2.
This approach differs from “gross zero,” which implies the complete elimination of all emissions. Eliminating all emissions entirely is currently considered technologically and economically unfeasible for many essential sectors, making net zero a more realistic and actionable target, as it allows for a small amount of residual emissions balanced by removal.
Distinguishing Net Zero from Similar Terms
Understanding the nuances between terms like “net zero,” “carbon neutral,” and “climate positive” is important. Carbon neutral typically focuses on carbon dioxide emissions, aiming to balance them through reduction efforts and often relying on carbon offsetting. This means an equivalent amount of CO2 is prevented from entering or removed from the atmosphere, often through purchasing carbon credits from projects like reforestation or renewable energy initiatives.
Net zero, in contrast, takes a more comprehensive approach by covering all major greenhouse gases, including methane and nitrous oxide, across an organization’s or country’s entire value chain. While offsetting can play a role, net zero prioritizes deep, direct emissions reductions first, minimizing actual emissions before relying on removal methods for residual emissions.
Climate positive, also known as carbon negative, represents an even more ambitious state. It means an entity removes more greenhouse gases from the atmosphere than it emits, actively reducing their overall concentration. These initiatives often involve significant investments in carbon removal technologies or large-scale natural carbon sinks.
Pathways to Achieving Net Zero
Achieving net zero emissions involves a dual strategy: significantly reducing emissions from their sources and actively removing existing greenhouse gases from the atmosphere. Transitioning to renewable energy sources, such as solar and wind power, is a primary method for emissions reduction. Improving energy efficiency across buildings and industrial processes also reduces overall energy consumption.
Electrifying transportation, by shifting to electric vehicles, further contributes to reducing emissions, especially when coupled with a renewable energy grid. Changes in waste management, sustainable agricultural practices, and industrial process improvements also lower emissions at their source. These direct reduction efforts are considered the most effective way to address emissions.
Alongside reduction, methods for removing emissions from the atmosphere are necessary to achieve the net zero balance. Natural solutions include afforestation (planting new forests) and reforestation (re-establishing cleared forests). These trees naturally absorb CO2 through photosynthesis, storing carbon in their biomass and soils. Soil carbon sequestration through practices like no-till farming and cover cropping also enhances the soil’s ability to lock away carbon.
Technological solutions for carbon removal are also developing. Direct Air Capture (DAC) technology chemically scrubs CO2 directly from the ambient air for storage or use. Carbon Capture, Utilization, and Storage (CCUS) captures CO2 emissions from large industrial sources like power plants before they enter the atmosphere, then stores or utilizes the carbon. Bioenergy with Carbon Capture and Storage (BECCS) combines biomass energy generation with carbon capture, storing the CO2 released from burning plant material.
Global Commitments and Frameworks
The concept of net zero gained prominence with the adoption of the Paris Agreement in 2015. This international treaty established a long-term goal to limit the increase in global average temperature to well below 2°C above pre-industrial levels, ideally 1.5°C. Achieving this requires global greenhouse gas emissions to reach net zero in the second half of this century.
The Paris Agreement operates on a five-year cycle, where countries submit increasingly ambitious national climate action plans, known as Nationally Determined Contributions (NDCs). These NDCs outline specific actions countries will take to reduce emissions and adapt to climate change impacts. As of November 2023, around 145 countries had announced or were considering net zero targets, covering close to 90% of global emissions and 92% of global GDP. For instance, the United Kingdom aims for net zero by 2050, Finland by 2035, and the United States has also pledged to achieve net zero emissions by 2050.
Beyond national commitments, there has been a rise in corporate net zero pledges as part of broader sustainability strategies. Over half of the world’s largest companies have now set net zero targets, reflecting increasing pressure from regulators, investors, customers, and employees. Many companies align their targets with frameworks like the Science Based Targets initiative (SBTi), which provides guidelines for setting emissions reduction goals consistent with the Paris Agreement’s 1.5°C target. These corporate commitments aim to reduce emissions across their operations and supply chains.