The Global Carbon Budget
What is the carbon budget?
The term "carbon budget" refers to the amount of carbon dioxide and other greenhouse gases that can be emitted into the atmosphere over a specific period of time without causing global temperatures to rise above a certain level. The carbon budget is expressed in terms of a maximum amount of CO2 equivalent emissions that can be released before we exceed that level due to an almost linear relationship between cumulative emissions and temperature rise.
It is calculated using a variety of factors, including the amount of CO2 already present in the atmosphere, the rate at which emissions are being released, and the sensitivity of the climate to changes in CO2 levels. The Intergovernmental Panel on Climate Change (IPCC) is the leading organization responsible for calculating carbon budgets.
And the budget is essential because it provides a framework for limiting global warming to a specific target – something to measure against. The Paris Agreement, which was signed by 196 countries in 2015, aims to limit global warming to "well below" 2°C above pre-industrial levels. To achieve this target, the IPCC estimates that the world can emit no more than 1,000 gigatons of CO2.
According to the Mercator Research Institute on Global Commons and Climate Change, we have just over six years (yr. 2029) until we break 1.5°C and just under twenty-four years (yr. 2047) until we break 2°C. This calculation uses a standard rate of emissions based on years up to 2020. It assumes CO2 emissions of 42.2 Gt per year, or 1,337 tonnes per second. While actual global emissions are variable and not constant year over year, the Carbon Clock gives a realistic countdown until these temperature levels are breached.
By calculating and tracking the global carbon budget, we can prioritize efforts to reduce emissions and measure progress toward our climate goals. It also provides policymakers with a clear target for emissions reductions and allows them to make informed decisions about where to allocate resources and invest in green technologies.
Overall, the carbon budget is a crucial concept in the fight against climate change. By understanding the level of emissions remaining before exceeding a particular temperature increase, we can prioritize efforts to reduce emissions and track our progress towards our climate goals. As individuals, we can also do our part by reducing our carbon footprint through actions like driving less, using energy-efficient appliances, and eating a plant-based diet. However, it has been shown by the Carbon Majors Database that 100 fossil-fuel companies are responsible for more than half of global emissions since the start of the industrial revolution in 1751. So, the true needle-moving actions lie in the hands of fossil-fuel companies, other large corporations, and governments. We need national governments to set real goals, establish new policy with consequences, make swift changes, and provide the resources and assistance to achieve the goals. Together we can work towards a more sustainable future, but it will take wide scale, global cooperation.