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Net-zero emissions: the story on HearLore | HearLore
— Ch. 1 · Defining Net Zero Concepts —
Net-zero emissions.
~4 min read · Ch. 1 of 7
Global net-zero emissions are reached when greenhouse gas emissions and removals due to human activities are in balance. This state stops further global warming once achieved. People often use the terms net-zero emissions, carbon neutrality, and climate neutrality with the same meaning. However, some standards for carbon neutral certification allow a lot of carbon offsetting. Net zero standards require reducing emissions to more than 90% before offsetting the remaining 10%. Organizations often offset their residual emissions by buying carbon credits. Reaching net zero is necessary to stop further global warming. It requires deep cuts in emissions, such as shifting from fossil fuels to sustainable energy.
Historical Scientific Origins
The idea of net-zero came out of research in the late 2000s into how the atmosphere reacted to CO2 emissions. This research found that global warming will only stop if CO2 emissions are reduced to net zero. The term gained popularity after the Intergovernmental Panel on Climate Change published its Special Report on Global Warming of 1.5°C in October of 2018. That report stated that reaching net zero would halt anthropogenic global warming on multi-decadal timescales. An influential scientific review on net-zero emissions energy systems was also published in June of 2018. This document assessed the special challenges of actually reaching net-zero targets rather than just reducing emissions.
Global Policy Implementation
As of November 2023, around 145 countries had announced or were considering net zero targets. These targets cover close to 90% of global emissions and include some countries resistant to climate action in previous decades. Country-level net zero targets now cover 92% of global GDP and 89% of the world population. 65% of the largest 2,000 publicly traded companies by annual revenue have net zero targets. Among Fortune 500 companies, the percentage is 63%. To date, 27 countries have enacted domestic net zero legislation. There is currently no national regulation in place that legally requires companies based in those countries to achieve net zero.
Emissions Scopes And Accounting
The Greenhouse Gas Protocol divides emissions into three scopes for corporate accounting. Scope 1 covers all direct greenhouse gas emissions within a corporate boundary like fuel burned by company vehicles. Scope 2 covers indirect emissions from consumption of purchased electricity, heat, cooling, or steam. As of 2010, at least one third of global greenhouse gas emissions are Scope 2. Scope 3 emission sources include emissions from suppliers and product users known as the value chain. Scope 3 emissions were estimated to represent 75% of all emissions reported to the Carbon Disclosure Project. Some oil companies claim their operations produce net-zero emissions but do not cover emissions produced when customers burn the oil.
Carbon Removal Strategies
To balance residual emissions, actors may take direct action to remove carbon dioxide from the atmosphere. Alternatively they can buy carbon credits that offset emissions. Carbon credits can fund projects such as reforestation. Strong standards only allow removal-based offsets that have the same permanence as the greenhouse gases they balance. For example, methane has a lifetime of around 12 years while carbon dioxide lasts between 300 and 1,000 years. Accordingly, removals that balance carbon dioxide must last much longer than those balancing methane. Most carbon credits on the voluntary market today do not meet UN or ISO standards for permanent carbon dioxide removals.
Credibility And Greenwashing Critiques
The credibility of net-zero targets remains low because there is no binding regulation requiring a transition to net zero. While 61% of global carbon dioxide emissions are covered by some sort of target, credible targets cover only 7%. Tzeporah Berman, chair of the Fossil Fuel Non-Proliferation Treaty Initiative, has criticized net zero claims by fossil fuel companies as delusional and based on bad science. A consortium of climate scientists tracked commitments and found pledges grew from 7% of countries in 2020 to 75% in 2023. However very few met minimum requirements for a decent pledge. The UN Race to Zero campaign calls them starting line criteria requiring evidence of action taken towards reaching the target.
Political And Economic Impacts
In the mid-2020s net zero became more politically divisive in places like the USA, EU, and UK. Some politicians have described net zero targets as harmful or too expensive while media says it will increase prices. The International Monetary Fund estimates that shifting policies to bring emissions to net zero by 2050 would result in global gross domestic product being 7 percent higher. In its estimates, the cost of emissions reductions in 2050 is less than 2% of world GDP. There are also implications for the workforce with some industries and regions more at risk than others. In the UK heavy industry concentrated in the Midlands and the North faces different risks compared to service sector jobs in London.
When did the term net-zero emissions gain popularity?
The term gained popularity after the Intergovernmental Panel on Climate Change published its Special Report on Global Warming of 1.5°C in October of 2018.
How many countries had announced or were considering net zero targets as of November 2023?
As of November 2023, around 145 countries had announced or were considering net zero targets.
What percentage of global greenhouse gas emissions are Scope 2 emissions as of 2010?
As of 2010, at least one third of global greenhouse gas emissions are Scope 2.
Why does methane require different offset standards than carbon dioxide?
Methane has a lifetime of around 12 years while carbon dioxide lasts between 300 and 1,000 years so removals that balance carbon dioxide must last much longer than those balancing methane.
What is the credibility status of net zero targets according to recent data from 2023?
While 61% of global carbon dioxide emissions are covered by some sort of target credible targets cover only 7%.