You will probably hear the term “net zero emissions” a lot in the coming weeks, as government leaders and CEOs under pressure talk about how they will reduce the impact of their countries or companies on climate change. Amazon, for example, has just announced that more than 200 companies have joined its climate pledge, which commits to reaching net zero emissions by 2040.
But what do net-zero emissions really mean?
“Zero emissions” – without “net” reservations – means that no greenhouse gases are emitted.
“Zero-zero emissions” have more room to maneuver. It’s like balancing a checkbook. The country or company reduces most of its emissions through efficiency and clean energy and then offsets the rest by removing carbon dioxide from the atmosphere or eliminating emissions elsewhere.
For example, trees absorb carbon dioxide from the air, so they are often considered “negative emissions”. The small Himalayan kingdom of Bhutan may require net zero emissions because almost all of its electricity comes from hydropower and its forests collect about three times more carbon than its vehicles, factories and other human activities emit.
Businesses have a different way of claiming zero-zero emissions — they can take advantage of CO2 reductions elsewhere by buying CO2 credits. For example, a U.S. company may pay to protect forests in South America and then subtract the negative emissions of those trees from its own emissions to say that its operation is “net-zero.” Other CO2 credits support sustainable development projects, e.g. Installation of wind or solar energy in poorer countries.
But counting on carbon credits also brings criticism because it allows these companies to keep generating greenhouse gases. Other concerns are that some projects would happen anyway, the emission reductions may not be permanent or even verifiable, or they may be double-counted by more than one entity. Some projects, such as tree planting, can take years to pay off in emission reductions, while companies that purchase forest compensations continue to emit greenhouse gases.
Why do net zero emissions matter?
Greenhouse gases capture heat near the Earth’s surface. When their concentrations become too high, they nourish global warming.
In 2015, countries around the world agreed to limit global warming to well below 2 degrees Celsius (3.6 degrees Fahrenheit) compared to pre-industrial times with a target of 1.5 C (2.7 F). To keep warming below 2.7 F with the least disruption, the UN says the world must be on track to reach net zero emissions by around 2050. To put these temperatures in perspective, global warming today is just over 1.8 F above pre-industrial levels, and rising seas and extreme weather are already a problem.
Several countries, including the United States, have promised to reach the zero-emission target by 2050. However, when the UN analyzed each country’s commitments under the Paris Agreement in mid-September, they found that they were still so short, that even if each promise is fulfilled, temperatures will rise around 4.86 F in this century.
Keeping global warming to 1.5 C will require negative greenhouse gas emissions. Climate Analytics and NewClimate Institute
How a company gets to net-zero emissions
To see how a company can get to net-zero emissions, let’s imagine a hypothetical company, ChipCo, that makes, packages and distributes potato chips. ChipCo buys electricity from a local utility company to run machines at the factory. It also has boilers to generate steam for heating the building and for some production processes. And it uses trucks to transport its products to customers. Each step generates greenhouse gas emissions.
To achieve zero emissions, ChipCo’s first step is to increase energy efficiency. Improvements in insulation and equipment can reduce the amount of energy needed or wasted. A simple example is to replace incandescent bulbs that use 60 watts of energy with LED bulbs that emit the same brightness but still use only 8 watts.
The second step is to shift from fossil fuels — the leading source of man-made greenhouse gas emissions — to renewable energy, e.g. Solar or wind power that does not produce greenhouse gas emissions. When the company’s electricity is renewable, the use of electric trucks further reduces emissions.
Homes and office buildings can also be built according to grid-zero or carbon-neutral standards. In that case, the focus is on making them extremely energy efficient and relying on heat and electricity from clean energy sources.
There must be a consistent path for improvements in energy efficiency and clean energy, not just promises and CO2 offsets.
ChipCo’s third step is to find negative emissions. It may be too expensive or not yet technologically possible to replace its steam boiler with a carbon neutral product. Instead, ChipCo can buy carbon credits that would remove the same amount of carbon from the atmosphere that would be generated by the boiler.
Companies are increasingly under pressure from governments, activists and their customers as well as some strong investors to reduce their emissions.
To see if a company takes its responsibilities seriously, look at its action plan and performance so far. A company announcing a net-zero target for 2030 cannot wait until 2029 to trade. There must be a consistent path for improvements in energy efficiency and clean energy, not just promises and CO2 offsets.
This article is republished from The Conversation under a Creative Commons license.