Setting a net-zero emission goal

Guidance for health systems


The imperative

The Lancet Commission characterized climate change as both the “biggest global health threat” and the “greatest global health opportunity” of the 21st century. According to the Intergovernmental Panel on Climate Change (IPCC) 2018 report, we need to cut emissions in half by 2030 and get to net-zero emissions by 2050 to keep warming to 1.5°C and avoid the most catastrophic impacts of climate change.

Solving health problems always starts with setting a goal. Establishing a leadership-endorsed, ambitious target motivates staff and helps drive strategies and resources for success.

There are three key drivers for health systems to set ambitious emission reduction goals:

  1. The imperative: Climate change is already damaging human health and will have a greater impact in the future – disproportionately impacting people of color, low-income communities, children, and the elderly. Climate change affects health and health care delivery, and hospitals are dealing with the impacts today. Reducing greenhouse gas emissions (GHG) emissions protects the health of patients, employees, and communities.
  2. Mission alignment: Health care is responsible for 8.5% of U.S. GHG emissions, with hospitals generating over one-third of those emissions. A health system cannot simultaneously contribute to climate change and meet its mission to “do no harm.” Eliminating GHG emissions also has the potential to reduce or eliminate other pollutants such as NOx, SOx, and particulate matter that harm the health of communities.
  3. Operational benefits: Health systems are on the front line of climate change, bearing the costs of increased diseases and more frequent extreme weather events. Reducing GHG emissions leads to cost savings and makes health systems more resilient in the face of climate impacts. 

Setting a net-zero goal

In April 2021, Health Care Without Harm published the Global Road Map for Health Care Decarbonization to chart the course for zero emissions health care by 2050. According to the 2018 IPCC special report on global warming, we have a decade left to institute “far-reaching and unprecedented changes in all aspects of society” to reduce global GHG emissions by half by 2030 and reach zero emissions by 2050.

In alignment with this Road Map, Health Care Without Harm and Practice Greenhealth recommend health systems set a net-zero goal for no later than 2050 in line with limiting warming to 1.5°C and set interim targets for 2030 and 2040 to manage and demonstrate progress towards that goal. 

Health Care Without Harm and Practice Greenhealth define a net-zero goal as a trajectory goal that requires an entity to set distinct CO2e emissions reduction targets in line with limiting warming to 1.5°C before considering the use of offsets. The goal must include emission reductions across all scopes. 

Given this is a trajectory goal, health systems will need to:

  • Set interim targets, in line with global efforts to limit warming to 1.5°C, including 50% greenhouse gas reduction by 2030 from baseline. A baseline year for emissions should be set by hospitals and health systems based on data availability. 
  • Focus on reducing all Scope 3 emissions but include at least 67% of Scope 3 emissions in the goal boundary (consistent with the Science-Based Targets initiative) based on materiality and peer benchmarking. 
  • Include additional Scope 3 emissions as measuring tools and data become available. The added emissions categories may have different baselines than those included in the original inventory.
  • Develop separate plans for decarbonization and residual emissions. Residual emissions must be separately and transparently identified and reported so that reducing emissions remains the primary focus. The National Health Service of England estimates that residual emissions are likely to be in the order of 4-8% of emissions for its health system by mid-century based on future innovation and research. 
  • Prioritize decarbonization and recognize health systems' ability to influence Scope 3 emissions from the supply chain through operations and care delivery based on how they choose, use, and dispose of products, as well as setting expectations for suppliers to decarbonize.

Important Definitions

Zero emissions is the point where an entity does not produce any CO2 equivalent emissions and is totally emissions-free, without any compensation mechanisms (e.g., offsets). It should be the ultimate goal of decarbonization. Zero carbon emissions can be achieved by reducing energy use through energy efficiency and conservation, electrification of vehicle fleets and building operations, and a shift to 100% renewable energy sources such as wind and solar. Many of these steps are cost-effective and achievable today, though not all. By making a long-term commitment to zero emissions, health systems can leverage their power in the policy arena and the marketplace to encourage the further investment, innovation, and technological research necessary to achieve a truly emissions-free world.
Net zero and carbon neutrality are both terms used to describe when the amount of greenhouse gases added to the atmosphere by an entity is balanced or offset by an equal amount of greenhouse gas emissions removed from the atmosphere. This is achieved by emission reduction efforts and then engaging in emission removal ( (e.g., reforestation efforts or carbon capture and sequestration) or purchasing offsets for the remaining emissions.

Net zero is preferred because it points to a faster pace of decarbonization across all scopes and then only considers compensation mechanisms for emissions that are particularly difficult to mitigate despite all the targeted interventions, investment, and focus. 

Carbon neutral versus net-zero goals

  Carbon neutral Net zero

Scope of climate impacts

CO2 or GHG emissions
(depends on standard used).

All GHG emissions

Scope of activities

Any portion of the organization

Any combination of Scope 1, 2, or 3 emissions.

All Scopes 1, 2, and material

Scope 3 emissions of entire organization

Mitigation mechanisms

Flexible on extent of emissions reduction vs. offsetting

(focus on cost-effectiveness).

Maximize emissions reduction before applying offsetting solutions
(less flexibility to apply cost-effectiveness filter)


Chosen by organization.

No later than 2050, with interim target of 50% reduction by 2030
(in line with Paris Agreement to limit warming to 1.5°C)


PAS2060, Carbon Neutral Protocol.


Adapted from a table by ENGIE Impact

Residual emissions are emissions that are generally recognized by the sector as particularly difficult or expensive to remove despite targeted interventions, investment, and focus. Residual emissions in health care are expected to decrease over time as climate commitments in health care and other sectors spur innovation in the marketplace, making alternative technologies and supplies widely available. The health care sector will also need to use its influence and purchasing power to move markets and promote innovation.  
Carbon offsets are projects or activities that reduce emissions of greenhouse gases to compensate for emissions created elsewhere. Carbon offsets are controversial because it is difficult to demonstrate that they are additional measures that permanently remove greenhouse gasses from the atmosphere. In addition they may generate wider ecological or societal damage in their application, create a false sense of emissions reduction, and distract from the main goal of decarbonization. Managing residual emissions through carbon offsets should not be viewed as a replacement for feasible actions to reduce an organization’s footprint, but rather as a temporary solution for specific hard-to-abate emissions until practical solutions become available. 
For U.S. health systems that have set ambitious, more near-term carbon reduction goals, purchasing carbon offsets may be necessary. Given that the carbon offset market is still evolving, there is an inherent level of risk in selecting projects and there are past examples of projects that did not meet their promised reductions or had unintended impacts. To address these concerns, Health Care Without Harm and Practice Greenhealth have developed a set of guiding principles for carbon offset purchases. 
For more information, see our net-zero goals FAQs.

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