To keep global warming below 1.5 degrees Celsius, we need to ensure that global emissions reach their peak by 2050 and reach net zero by approximately 2060. Achieving net zero means eliminating all remaining emissions through carbon removal strategies.
Net zero must be interpreted to include equity guardrails that ensure the transition to low-carbon economies is fair for all countries and population groups. These equity guardrails must be in place regardless of each country’s path.
Reducing Carbon Dioxide Emissions
The facts are clear: to prevent the severe consequences of climate change and maintain a habitable Earth, worldwide carbon emissions must be decreased rapidly until they reach net zero. This means reducing anthropogenic (human-caused) emissions to zero while ensuring that any remaining greenhouse gases are removed from the atmosphere, such as through oceans and forests.
To get to net zero, many activities must be scaled up or accelerated. These include switching to low-carbon technologies, expanding energy efficiency, halting deforestation, and increasing efforts to restore natural environments that can act as carbon sinks. It also requires front-loading emission reductions to begin taking steps to reduce emissions as soon as possible. This is important because research has shown that if we delay cutting emissions, it will be harder to keep the temperature below 2°C – the level at which climate change will cause widespread damage to human societies and natural systems.
Achieving net-zero emissions will require various policies, varying from country to country. For example, emissions from agriculture and food can be reduced by using greener farming methods and moving away from high-carbon animal feeds like ruminant meat. Industries can decrease their greenhouse gas emissions by utilizing renewable energy sources and enhancing energy efficiency instead of fossil fuels.
Boosting Economic Growth
Many countries have set long-term goals for achieving net zero carbon emissions by 2050 and beyond. This ensures that future economic growth will be sustainable in the face of climate change. To do this, it will be necessary to boost productivity growth so businesses can invest in low-carbon technologies and other innovations. Reducing excessive income and wealth inequality levels that limit investment and growth will also be necessary.
Scientists widely accept that limiting global warming will require deep and rapid reductions in human-caused greenhouse gas emissions to reach net zero around mid-century. It is extremely unlikely that the emissions of some sectors can be reduced to zero in time – for example, aviation and agriculture – so an equivalent amount will need to be removed from the atmosphere through effective carbon capture and storage or other harmful emissions, such as reforestation. These will be known as residual emissions’ or ‘negative emissions.’
Enhancing Human Health
Climate change is a significant threat to human health. Its impacts include direct hazards such as heat waves, droughts, floods and indirect effects such as vector-borne diseases and malnutrition.
Reaching net zero carbon emissions requires a near-complete transformation of how society produces, consumes, and lives – flipping everything from energy to transportation to buildings and food production systems over to more efficient and environmentally conscious alternatives. It will also require a wide use of effective carbon removal and long-term storage.
To stay within an acceptable temperature rise (a societal choice), the world needs to cut all emissions and increase carbon sinks in a way that can be maintained over decades. This balance is often called ‘hard net zero’ or oral zero’ (as opposed to softer targets like ‘carbon neutral,’ which refers only to CO2 in the atmosphere).
Emissions reductions and carbon storage must be on the scale of millions of gigatons per year. It is unclear how this can be achieved – or if it will be possible – because the current level of emission cuts falls far short. Moreover, the effectiveness of these cuts is limited by the availability of suitable land and oceans for carbon sequestration.
Enhancing the Environment
As the Paris Agreement underscores, net zero is an important goal for limiting climate change impacts and avoiding dangerous tipping points. It requires reducing ongoing greenhouse gas emissions and counterbalancing them through carbon removal measures (e.g., reforestation, restoring peat bogs and mangroves). It also calls for rapidly replacing coal with renewable energy sources, enhancing energy consumption efficiency, and conserving “carbon sinks” like forests.
To meet this ambition, countries submit nationally determined contributions (NDCs) plans to set their long-term net reduction targets. However, critics have raised concerns that these goals can be manipulated by reliance on carbon removal strategies that delay emission reductions within a country. To combat this, the NDCs must align with a country’s long-term low-emissions development strategy and be transparent about what is required to achieve net zero by around mid-century.
In addition, the benefits of achieving net-zero emissions must be shared equitably. For example, limiting climate damage to 1.5°C could avoid up to 24% economic loss in developing Asia compared to unabated warming, according to the Asian Development Bank (ADB). This can be achieved through policies that accelerate the transition from high-carbon industries to a cleaner energy economy and improve air quality – all while protecting vulnerable communities and reducing unemployment. Reaching net zero may also reduce the frequency and severity of regional hydrometeorological events such as droughts, flash floods, and wildfires.
