This speech, given to the Canadian Council of Chief Executives, contains a basic error about the nature of climate stabilization. In part, it reads:
Never losing sight of the ultimate long-term objective of the exercise – stabilizing the level of man-made greenhouse gas emissions in the atmosphere at non-dangerous levels not in 2020, or even 2030, but 4 decades hence in 2050. Recognizing that we are running a marathon, not a sprint; and acting accordingly. (emphasis in original)
As stated, this is a very ambitious goal. Stabilizing the global concentration of greenhouse gasses by 2050 would mean reaching the point of zero net human emissions in that year. That would require either the total elimination of fossil fuel use and deforestation, or the deployment of technologies that capture greenhouse gasses from the atmosphere and sequester them.
Right now, greenhouse gas concentrations are about 385 parts per million (ppm), and rising at 2 ppm per year. Even if they kept up that rate between now and 2050, concentrations would ‘only’ rise to 469 ppm – a figure not enormously higher than the commonly cited target of 450 ppm. Of course, it is unlikely that emissions per year would stay completely flat until 2050, then drop instantly to zero.
Given the other contents of the speech (such as affirming that 80% of North American electricity will come from oil and gas in 2020), I don’t think the literal meaning of the passage quoted is the one intended. I fear, instead, that rather than talking about stabilizing concentrations of greenhouse gasses, the speaker may have been talking about stabilizing emissions. If so, this is a disastrous suggestion. If we are to avoid dangerous anthropogenic climate change, global emissions almost certainly need to peak between 2015 and 2020, declining sharply after that.
A simple analogy to personal debt easily explains the difference between concentration and emission stabilization. If you are going into debt because you are spending more each year than you earn, stabilizing your level of spending is not going to get you out of debt. It will just leave you in the position where your level of debt increases by the same amount every year. Stabilizing your debt requires that your expenditures match your income every year. While your level of wealth is lower than it was when you started, it is still stable. So too it will be when humanity reaches the point of zero net greenhouse gas emissions: what we already put in the atmosphere will stay there for hundreds of thousands of years, but at least we will no longer be adding to it.