The Global Carbon Budget is an effort by carbon scientists and the Global Carbon Project to measure carbon levels. This is set up by experts by looking at the exchange of carbon between the atmosphere and the biosphere in the carbon cycle while also factoring changes in land and ocean carbon sinks given the increase of carbon from human activities.
The use of the Global Carbon Budget allows for us to understand the seriousness of carbon emissions. The 2011 budget laid out an amount of 400 billion tonnes of carbon to keep global temperatures below 1.5 degrees Celsius. In 2016, this was reduced to 205 billion metric tons, according to research the use of fossil fuels have reduced this and setting a limited time of approximately five years before the new allotment will be used up.
Carbon Brief. “Analysis: Only five years left before 1.5C Carbon Budget is blown.” https://www.carbonbrief.org/analysis-only-five-years-left-before-one-point-five-c-budget-is-blown. Accessed August 8, 2016.
United States Department of Energy. “Global Carbon Budget.” Carbon Dioxide Information Analysis Centre. http://cdiac.ornl.gov/GCP/. Accessed August 8, 2016.