Dr Michael Mann published results of calculations in the March Scientific American in 2014, that show it is very likely that by 2036 earth will have crossed the threshold beyond 2° C of average warming.   The date on the web page is April 1 2014, but this is no joke.  On this view, to avoid the 2° C we have to stop pumping CO2 into the atmosphere right now.

• New calculations by the author indicate that if the world continues to burn fossil fuels at the current rate, global warming will rise to two degrees Celsius by 2036, crossing a threshold that will harm human civilization.
• To avoid the threshold, nations will have to keep carbon dioxide levels below 405 parts per million.

As of today, 25th June 2017,  the NOAA global CO2 trends shows that  the average global value for March 2017 is 406 parts per million. On current trends we reach environmental ruin by 2036.  Warming doesn't just stop at 2° C.

As Dr Mann writes in the article, the long term behavior of earth systems regards to greenhouse warming can be characterized by a single number, known as the Equilibrium Climate Sensitivity - ECS.  This is how many °C warming for a doubling of greenhouse gases.  The greenhouse gases effect earths energy balance, by causing our oceans and atmosphere to retain more heat energy, and further warming melts large areas of reflective ice and tundra, which reduces earth's albedo, and reduced reflectivity also contributes to faster and greater warming. Dr Mann explained that an ECS 2.5 - 3.0°  C model best fits the warming rates we have already experienced, and that the true value is likely to be closest to 3° C.

The IPCC only takes fast climate system feedback processes into account, when it estimates that a limit of 450 ppm CO2 is a limit for 2° C of warming. Slower feedback processes contribute to further warming later on. Taking the longer term processes into account, leads to a much lower estimate of a safe level of CO2, something below a threshold of 350 ppm, which was first recorded at Mauna Loa around 1990.

Based on the current rapid growth in atmosphere CO2 of about 2.9 ppm a year, without further change or acceleration in CO2 growth, we reach 450 ppm in the year 2032.

Which is why I struggle hard to understand the delusions that the latest "Carbon Tracker Report" , is based on, as it talks about dividing future investment into CO2 emissions  (capex), to the year 2025, into "good" and "bad" investment, as it considers current emissions production rates, to the year 2035, and assumes a generous global carbon CO2 budget based on 450 ppm. It is based on a slim hope that ECS is on the lower side of 3° C, and that some miracle will happen later on, other than the total collapse of global civilization, to prevent the human experience of the results of the less considered slower climate system feed-backs.

Still the report, entitled "2 degrees of separation : Transition risk for oil and gas in a low carbon world", does make it clear, even given the best of all positive hopes, that by 2025 we are already going to have wasted large amounts of our investment resources on making more fossil fuel CO2 emissions. 

In the "executive summary" it states

US$2.3trn – around one third – of potential capex to 2025 should not be deployed in a 2D scenario compared to business as usual expectations.

Company level exposure varies from under 10% to over 60% when considering the largest 69 publicly traded companies.

Around two thirds of the potential oil and gas production which is surplus to requirements in a 2D scenario is controlled by the private sector.

A table of the most exposed 69 global companies for 'stranded assets' based on their optimism scenario modelling, listed a few Australian based corporations, with the percentage range of capex outside their presumed 2° C capex budget, total projected emissions,  a potential average allocation of extra Gt of CO2 that will be produced

Woodside - 40-50%  0.7 Gt,   0.3 Gt

Origin Energy - 30-40%    0.3 Gt,  0.1 Gt

Santos - 20-30%    0.4 Gt,  0.1 Gt

A lot of this private development, at the end of fossil fuel age, is into relatively high cost projects, and the report notes a distinct lack of transparency.

Increased transparency required
Oil and gas companies have options in terms of which new projects they plan to develop in the future. At present there is little transparency of these strategies, making it difficult for investors to understand and test the degree of alignment with a 2D scenario. Companies may have already decided to put a number of high cost projects on hold, but more can be done to tell this story to their shareholders.