Do you feel a bit lost when people refer to certain environmental sustainability topics and aren’t sure where to start when it comes to learning more? Sustainability 101 is a blog series that you can turn to for information about different environmental terms that may come up at work, during discussions with friends, and even at your annual holiday gathering.

“It’s possible to reach net-zero carbon emissions. Here’s how” 1

“UN tells governments to ‘fast forward’ net zero targets” 2

These are just a few of many headlines from 2023 so far that center around the concept of “net zero.” You may hear the phrase frequently in the context of climate change and global warming, but do you know the intricacies behind it?

According to the United Nations (UN) Climate Action website, net zero “means cutting greenhouse gas (GHG) emissions to as close to zero as possible, with any remaining emissions re-absorbed from the atmosphere, by oceans and forests for instance.”

Similarly, the World Resources Institute (WRI) says net zero “will be achieved when all emissions released by human activities are counterbalanced by removing carbon from the atmosphere in a process known as carbon removal.”

Simply put, it is a state where emissions are balanced with an equal amount of GHG removal.

Why has net zero become such a commonly used term? Because our future depends on it. According to the Intergovernmental Panel on Climate Change (IPCC), “climate-related risks to health, livelihoods, food security, water supply, human security, and economic growth are projected to increase with global warming of 1.5°C” [compared to pre-industrial levels]. To stay below that temperature threshold, global emissions must decline by about 45% from 2010 levels by 2030 and reach net zero by 2050.

Achieving a state of net zero requires a two-part approach, according to WRI:

  1. Reduce human-caused emissions, such as those from fossil-fueled vehicles and factories, as close to zero as possible.
  2. Remove any remaining emissions by balancing those with an equivalent amount of carbon removal from the atmosphere.

How can we reduce human-caused emissions?

According to the UN’s Climate Action website, burning fossil fuels — think coal, natural gas, and oil — to generate power, manufacture goods, and fuel transportation accounts for over 75 percent of global GHG emissions and nearly 90 percent of all carbon dioxide (CO2) emissions.

Some other activities that create emissions include: deforestation or wildfires (because trees absorb carbon from the atmosphere during their lifespan and release it when they are destroyed) and non-sustainable food production, which releases large amounts of CO2, methane, and other GHGs into the atmosphere. (You can read more about GHG emissions sources in our previous Sustainability 101 blog.)

Actions that can reduce GHG emissions, according to the WRI, include:

  • Shifting to electric vehicles
  • Transitioning to clean, renewable energy from sources like wind and solar
  • Increasing public transportation, biking, and walking
  • Retrofitting buildings and improving energy efficiency
  • Reducing food loss and waste

How can we remove carbon from the atmosphere?

Carbon removal can either be nature based or technology based. Common examples of nature-based removal projects are afforestation (planting new trees to create a forest) or reforestation (replanting trees where they previously existed) — because trees absorb CO2 through photosynthesis. Protecting and restoring other natural ecosystems, such as peatlands, coastal wetlands, savannas and grasslands, can contribute to carbon sequestration as well.

A number of technology-based carbon removal solutions are in various stages of development. One is direct air capture — the process of “chemically scrubbing CO2 from the ambient air and then sequestering it either underground or in long-lived products like concrete,” according to the WRI.

Another example that is in the demonstration phase according to the IPCC is a process known as “bioenergy with carbon capture and storage” (BECCS). Atmospheric CO2 is absorbed by plants and trees as they grow, and then the plant material (biomass) is burned to produce energy. The CO2 released in the production of this energy is then captured before it reaches the atmosphere and stored in geological formations deep underground on long time scales. This allows us to produce energy without adding additional GHGs to our atmosphere.

What actions are organizations taking?

Given the dire warnings from the IPCC and other scientific organizations, many companies, countries, and even individual cities are setting their own goals to reach net zero. According to Net Zero Tracker, as of 2023, more than 900 companies and 130 countries have set targets

In November 2022, a UN High-Level Expert Group issued a report that “set tight definitions for what it means to be net zero and net zero-aligned” for corporations, financial institutions, and local and regional governments. The report identified five principles for these “non-state” entities to set net zero goals:

  1. Ambition which delivers significant near- and medium-term emissions reductions on a path to global net zero by 2050
  2. Demonstrated integrity by aligning commitments with actions and investments
  3. Radical transparency in sharing relevant, non-competitive, comparable data on plans and progress
  4. Established credibility through plans based in science and third-party accountability
  5. Demonstrable commitment to both equity and justice in all actions

One organization offering third-party accountability on corporate net zero goals is the Science Based Targets initiative (SBTi), a partnership between CDP (formerly the Carbon Disclosure Project), the UN Global Compact (UNGC), WRI and the World Wide Fund for Nature (WWF).

In October 2021, the SBTi established its Net-Zero Standard, the world’s first framework for corporate net zero target setting in line with climate science. Cisco was among the first technology hardware and equipment companies to have its net-zero goal and near-term targets validated under the SBTi Net-Zero Standard. SBTi validation requires companies to reduce emissions across their value chains by at least 90 percent. Companies with SBTi validation can use offsets for no more than 10 percent of their emissions reduction. According to the SBTi, a company is only considered to have reached net zero when it has achieved its long-term science-based target and neutralized any residual emissions.

Learn more about Cisco’s goal to reach net zero GHG emissions across our value chain by 2040 on cisco.com and our environmental, social, and governance (ESG) Reporting Hub.

Willing to learn and engage more on environmental sustainability? In the next blog in our series, we will share more about smart buildings and what it means.



1 Science News – It’s possible to reach net-zero carbon emissions. Here’s how

2 Climate Change News – UN tells governments to ‘fast forward’ net zero targets



Natalie Stubb

Net Zero Strategy Lead

Chief Sustainability Office