Country Carbon Budgets

How much must a country's net CO2 emissions be reduced to meet the Paris Agreement?

Equitable Carbon Budgets per Country

The total global carbon budget can be divided per country. Dividing the global country budget into country budgets can be done in many different ways. One way of doing it is to divide the global budget into a budget per person, and then assigning a budget to a country based on its population. This is often considered an equitable way of dividing the budget. This way to divide the budget is used on this page. The current population is 7.7 billion, which means that the global budget to limit warming to 1.5°C above pre-industrial (1850-1900) levels with a 66% probability of 420 GtCO2 implies a personal carbon budget of 54.5 tCO2. (1 tCO2 = 1 billion tonnes (metric tons) CO2.)

Only fossil fuels and cement are included in the country carbon budgets in the reduction scenario below, which means that they exclude e.g. emissions due to land use changes. The reason is that I have not found any recent and complete data for country emissions which include land use changes (LULUCF). Aviation and maritime emissions are also excluded, since they are not reported per country in the data set used for country emissions (GCP 2018).

How big is a country's equitable carbon budget?

Same emission reduction amount every year

One way of modelling emissions reductions is to reduce the emissions with the same amount every year. Every year of delay in action means that the emissions must reach net zero one year earlier.

How much (in MtCO2) must country emissions be reduced per year to reach net zero emissions before the carbon budget runs out?

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Same percentage of emission reductions every year

Another possible way of modelling emissions is to reduce the emissions by the same percentage amount every year, e.g. a 10% reduction of emissions every year. In the calculations below, all years with emissions above 1/100th of the emissions the start year are counted.

How much (in percent) must country emissions be reduced per year to reach net zero emissions before the carbon budget runs out?

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2030 goal vs net zero goal

The Emission Gap Report 2019 state that global GHG emissions would need to be 55% lower in 2030 than in 2018, to limit global warming to below 1.5ºC. The SR15 report state that net zero CO2 emissions must be reached in 2050 to be able to limit global warming to below 1.5ºC.
Since the total warming is depending on the total amount of CO2 emitted, there is a relationship between the 2030 goal and the net zero goal. If emissions are reduced more to 2030, the net zero point can happen later in time. Conversely, if emission are not reduced enough in 2030, the net zero point must happen a lot sooner.

What is the relationship between the 2030 and the net zero goals?

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Flat or increasing emissions

Currently, world CO2 emissions from burning fossil fuels are increasing with about 1% per year, and increased 2.7% in 2018. (Burning fossil fuels is by far the biggest contributor to CO2 emissions.)

How long does the budget last if country emissions continue increasing or stay flat?

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Global Carbon Budgets | Country Carbon Budgets | What are Carbon Budgets?

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