In May 2017, the world atmosphere has been measured at 409.25 ppm CO2. There have been some measurements in Hawaii of 411 ppm. The levels rose from 407.42 ppm in April 2016.
For the odds to be greater than 66 per cent probability of less than 2 degrees of warming, the CO2-e concentrations should be should be lower than 415 ppm. Within 2 to 3 years the world will be at 415 ppm concentration.
Previous calculations of 50 per cent probability of limiting warming to 2 degrees or less gives an allowable budget of Kyoto gases of approximately 2 020 Gt CO2-e over the period 2000–2050. A 67 per cent probability reduces the allowable budget to approximately 1 700 Gt (billion tons) CO2-e. By 2012, 35% of the 1700 billion tons had been used. Now in 2017 we have used more than another 10% and by the end of the year we will have used about half.
The Paris Agreement on climate is talking about emitting 745 billion tons of CO2 between the beginning of 2017 and the end of 2030 instead of 770 billions tons of CO2. This is the max if commitments were met. Currently we would be very lucky to get to 5 to 8 billion tons of total lower emissions because most countries are falling well short of slowing the increased CO2 emissions.
This means that the world reaches the same 770 billions tons of total CO2 emissions 60-180 days after Dec 2030.
There is no forecast to stop the growth in CO2 emissions until maybe the 2050s or 2070s. This is like the forecasts where the world population would peak in the 21st century. However, Africa is not lowering its birth rate as fast as expected so now there is no forecasted world population peak in the 2100s. If there is no peak in cO2 in the 2030s combined with some wishful rapid decline then the world will blow past 2 degree warming without massive climate intervention aka geoengineering.
Here are some obvious observations
* 98% people have not read the Paris Agreement
* 99.5% of people do not know the commitments of each country or even the major countries
* most people who talk about the climate science have not looked at the CO2 budget
* The Paris agreement would still barely slow the CO2 increase to 2030
* CO2 emissions will increase and we will blow through 2 degrees of warming and if we are unlucky we already did with a 30% likelihood
* Geoengineering will eventually have to be used if we really wanted a cooler world
I have been saying for over decade there needs to be mass production thousands of factory built nuclear power plants.
I have said that there are easy ways to sequester large amounts of CO2 inexpensively. By putting thousands of tons of iron filings in the ocean, algae blooms can be produced that feed salmon and other fish when they exist for a week or two then the algae die and sink to the bottom of the ocean taking millions of tons of CO2 with them.
I will not say the Paris Agreement is useful for a problem when it is not. Nextbigfuture has written dozens of articles about solutions that would be effective.
Using the chart, if you go the right you are looking at chances for 3 degrees or 4 degrees of warming and the levels of CO2 ppm.