How long until we use up our carbon budget?

Confidence basically means what % of models used will stay below the target 'max temperature rise'. A full description is from the document cited above and is:



Cumulative CO2 emissions at the time of peak warming from WGIII scenarios for which a fraction of greater than 66% (66 to 100%), greater than 50% (50 to 66%) or greater than 33% (33 to 50%) of climate simulations keep global mean temperature increase to below the stated threshold. Ranges indicate the variation in cumulative CO2 emissions arising from differences in non-CO2 drivers across the WGIII scenarios. The fraction of climate simulations for each scenario is derived from a 600-member parameter ensemble of a simple carbon-cycle climate model, Model for the Assessment of Greenhouse Gas Induced Climate Change (MAGICC), in a probabilistic mode. Parameter and scenario uncertainty are explored in this ensemble.



Rate assumed at the beginning of 2017 is 39.5 gigatons/year which is roughly the average of the last three years from Global Carbon Budget

Can I Use This In My Site?

Yes. You can embed this page though it looks bad when you do so I made a version that should embed well in most situations. It is here: http://cityprojections.com/carbonclock.php. Just stick it in as the src for an iframe. You can pass in various url parameters. They are:

size - 0 is small; 1 is medium; 2 is large; 2 is default

likelihood - confidence setting above...3350 is 33 - 50%; 5066 is 50 - 66%; 66 is >66%; 66 is default

target - 1.5 = 1.5 degrees; 2 = 2 degrees; 3 = degrees; 1.5 is default

buttons - 0 means hide all buttons; 1 means show them; 1 is default

growRate - anything under 0.9 means 0.9; anything above 1.1 means 1.1; anything between 0.9 and 1.1 is exactly that; 1 is default

Two example links showing how to use it are #1 and #2