Carbon offsetting

Balancing out: The average US citizen emits 20 tons of CO2 annually, compared to the global average of four.

Google recently claimed it had eliminated its carbon footprint. Meanwhile, China has announced plans to do the same by 2060. How do they do it – and why are some people not convinced?

  • What is carbon offsetting?

    Since the start of the Industrial Revolution, human emissions of carbon dioxide have risen to more than 35 billion metric tonnes per year.

    Gases that trap heat in the atmosphere are called greenhouse gases. As a heat-trapping gas, CO2 is the biggest contributor to climate change. The idea behind offsetting carbon is that the emissions generated through an activity — like flying — can be calculated, and then the equivalent amount “paid off” via a scheme that removes carbon from the atmosphere.

    As a result, the overall amount of carbon released into the atmosphere remains the same as before the emissions were generated.

  • What do people mean by net zero?

    In 2015, nearly 200 countries met in France for the UN climate change conference. There, they adopted the Paris Agreement. One of the most ambitious global climate agreements ever made, an important goal was for “net zero emissions” by the second half of the century. In other words, 100% of carbon emissions would be counterbalanced through offsetting.

    Many governments involved in the Agreement have now translated it into national aims: Austria plans to hit the target by 2040, while Uruguay hopes to work faster with a 2030 goal. Companies also have plans to go carbon neutral, with Google claiming in September to have offset all of its emissions.

  • How does it work in practice?

    Countries, companies and individuals can invest in offset schemes that work to remove the carbon created by their activity. To be effective, these schemes must be in addition to any carbon removal already taking place.

    The most popular offsetting activity is planting trees. It is the simplest and cheapest way to create a carbon sink. Another popular technique is restoring peat bogs. Heathrow Airport has invested £94,000 in such a project near Manchester.

  • What is carbon capture technology?

    Carbon dioxide remains in the atmosphere longer than any other heat-trapping gas. After a pulse of CO2 is emitted into the atmosphere, about 50% will be absorbed in the first 50 years, reaching about 70% by 100 years. Further sink absorption then slows dramatically, with an additional 10% only removed after 300 years, but the remaining 20% will last for tens, if not hundreds of thousands, of years before being removed.

    But natural carbon removers are not completely reliable. Trees, in particular, are susceptible to fires –and as they burn, fires will produce a huge amount of the very CO2 that the trees were expected to remove from the atmosphere.

    As a result, scientists are constantly trying to develop technology designed to remove carbon from the atmosphere and store it safely. One popular technology is designed to remove the gas and store it in building materials, such as concrete.

  • Does offsetting delay emissions reduction?

    According to many experts, it does. However, they worry that the prospect of being able to offset emissions could discourage governments, corporations and even individuals from taking immediate action to reduce emissions. For example, paying to offset a flight could stop someone from looking for greener travel options.

    One group of researchers at Lancaster University has concluded that the option of offsetting deters organisations from taking more urgent action.

  • Does that mean we shouldn’t bother?

    Not necessarily. Providing money for carbon capturing technology is good because it reduces carbon already in the atmosphere. However, most experts agree that to stop climate change, everybody must do more than simply becoming carbon neutral.

    Emissions can be reduced through using green energy, such as solar and wind. Individuals can make their contribution by instituting little changes: for example, by turning the lights off when not needed them and by switching the television off at the wall instead of leaving it on standby.

You Decide

  1. Should companies be forced to reduce their emissions instead of simply offsetting?


  1. Use this calculator to measure your ecological footprint. What could you do to lower it? Come up with a list of ways your household can help.

Word Watch

Industrial Revolution
The period of transition to new manufacturing processes in Europe and the United States – from about 1760 to sometime between 1820 and 1840.
Carbon sink
A forest, ocean, or other natural environment able to absorb large amounts of carbon dioxide from the atmosphere. The Amazon rainforest, for example, absorbs two billion tons of carbon dioxide each year.
Peat bogs
A kind of wetland that accumulates peat, a deposit of dead plant material—often mosses. Peat can be dried and burnt as a fuel, but there are now several projects underway to stop the removal of peat and restore the wetlands as they act as a useful carbon sink and a brilliant place for wildlife. Burning peat is also an activity that needs to cease.
Other heat-trapping gases include methane, nitrous oxide, halocarbons, ozone.
Likely or liable to be influenced or harmed by a particular thing.
Carbon neutral
Another term describing net zero emissions. Carbon neutrality is when an activity balances out any emissions with carbon removal – effectively “neutralising” the CO2 emitted.
Heat-trapping gas
Often described as a greenhouse gas, this is any gas in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere, rather than letting it escape. As a result, global temperatures rise.

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