The concept of net zero is founded in physical climate science. To keep temperatures within safe limits, a finite budget of carbon dioxide and other greenhouse gases must be allowed to enter the atmosphere — and any further emissions must be balanced by removal from sinks.
For CO2, this means achieving net zero emissions as soon as possible. For other greenhouse gases, it may involve using carbon removal technologies to offset ongoing emissions.
Reduce emissions by at least 90% by 2050
The international scientific consensus is clear: to prevent the worst climate impacts and preserve a livable planet, human-caused global emissions must be reduced to zero, with any remaining emissions removed from the atmosphere, such as by reforesting and capturing carbon in technologies like direct air capture and storage (DACS). The science also demonstrates that achieving net zero by around 2050 is critical if we limit the temperature increase to 1.5°C.
To achieve net zero goals, we must understand what is net zero emissions. To get to net zero, nations must set ambitious emission reduction targets, including as part of their Nationally Determined Contributions (NDCs) under the Paris Agreement — and then act aggressively to achieve those targets. To accelerate progress toward a zero-carbon world, a need for near-term targets with significant impacts and are held accountable using robust, transparent, and science-based frameworks.
In addition to CO2, we need to phase out other potent greenhouse gases, such as methane, nitrous oxide, and fluorinated chemicals, which are more challenging to eliminate than CO2. Countries’ net-zero plans must consider all GHGs and include policies that will reduce non-CO2 emissions with equal urgency.
Increasingly, investors support this goal with commitments to invest in net-zero projects and companies. But commitments alone are not enough: committed investors must also align their investment practices with the initiative’s goals by implementing management practices that will enable them to achieve these new targets and transition to a net-zero economy.
Reduce emissions by at least 100% by 2050
Getting to net zero requires reducing all emissions, not just those directly produced by companies. To reach net zero, most companies will need to cut their emissions by more than 90% and then neutralize any residual emissions with carbon removal, which could be achieved through natural approaches like restoring forests or using technologies like direct air capture and storage.
A growing coalition of governments, cities, and businesses is taking ambitious action to get to net zero. For example, the United States has joined a global net zero initiative to lead by example and achieve net zero government operations by 2050.
A growing number of cities, regions, and private sector companies have joined Race to Zero, a movement to take immediate action to halve global emissions. Over 3,000 businesses and 100 financial institutions have committed to science-based targets to reduce emissions. And over 900 cities, 100 regional governments, and more than 125 educational institutions have joined the Global Climate Declaration.
Achieving net zero will require a significant reduction of emissions in every sector, from reducing fossil-fuel use to capturing carbon from the atmosphere. This will be achieved in two steps: first, human-caused emissions must be reduced to as close to zero as possible; and second, any remaining emissions must be balanced with removals, whether by natural approaches like restoring forests or new technologies.
The latest science indicates that limiting warming to 1.5°C will require global greenhouse gas (GHG) emissions to reach net zero around 2050, a goal supported by the international community at the Glasgow Climate Pact. This milestone will provide a crucial buffer against climate impacts and allow time for carbon removal to return temperatures to safer levels.
Governments are leading by example through their own net-zero goals.
Real estate owners are also aligning with the net zero goal. This industry-led effort combines near-term action and accountability by calling signatories to set intermediate targets using robust scientific guidelines.
Getting to net zero will require deep cuts in all sources of greenhouse gases, including carbon dioxide. It will also require scaling up removals, which can be achieved by restoring forests and using technologies like direct air capture to scrub emissions directly out of the atmosphere. Achieving net zero will require a permanent balance between sources and sinks over matching time scales.
Switching from fossil fuels to renewable electricity can transform the energy sector responsible for three-quarters of emissions. However, more radical changes are needed to reduce emissions from sectors such as transport and agriculture. And the transition must be undertaken to protect jobs tied to high-carbon industries and distributes the costs and benefits of change equitably across society.
In addition to setting net reduction targets, countries must set ambitions for achieving them by 2050 and beyond. This will provide the necessary incentive for investments in green infrastructure and ensure that near-term goals and actions are consistent with longer-term ones.
Some governments have already begun leading by example, setting ambitious net-zero goals for their operations, including a commitment to achieving 100% carbon-free power for government buildings by 2050.