Thank you for the opportunity to again appear before you and to share with you some of the scientific understandings regarding the increasingly urgent need to address the threat of climate change. Much of what I have to say is contained in the recently completed IPCC fourth assessment report. My remarks will focus on the long term but also on the immediate future.
In general, decision-making concerning the appropriate level and pathways for greenhouse gas emission reductions will be an iterative and, as Ian mentioned, risk management process. An explicit long-term goal is regarded as being absolutely essential. Without such a goal, none of us--individuals, businesses, or other levels of government--have a clear direction for policy and action. Such a goal must be strong enough to stimulate the necessary ambition.
One also needs short- and medium-term objectives from which it is still possible to reach the desirable long-term goal. Once each short-term objective is reached, decisions on subsequent steps can be made in the light of new knowledge and the decreased levels of uncertainty.
Now, ideally, the choice of a long-term goal is the product of solid science and wise political decision-making. The science can inform the process, but in the end, it depends on what we value, and this is best determined through a political process.
To illustrate, we can consider a table from the IPCC Working Group II summary for policymakers, which I've distributed to each of you. I'm grateful for your indulgence in allowing me to distribute it only in English. I do apologize; it is also available in French on the IPCC web page, and I will give the details of that to the clerk.
The table brings together what we know about some of the anticipated climate change impacts across several key sectors--water, ecosystems, food, coasts, and health--as a function of globally increasing temperatures. As you go from left to right, the impacts occur at higher temperatures. If you value biodiversity, for example, you can see that a temperature rise above one degree Celsius could lead us to losing about 30% of species.
Many people who have looked at such diagrams and others have come to the conclusion, based again on value judgments, that we should avoid an increase of more than two degrees Celsius above 1990 levels. This is the goal adopted by the European Union and much discussed in Bali recently.
To understand what we would have to do to achieve this goal, we need to look at some of the so-called stabilization scenarios in the IPCC Working Group I contribution. It is estimated that if we are able to stabilize concentrations of all greenhouse gases in the atmosphere at the equivalent of 445 to 490 parts per million of CO2, then we could limit global mean temperature increases to between two and 2.4 degrees Celsius. That's above pre-industrial levels.
Such a stabilization level--that's roughly, as I said, 450 parts per million of CO2 equivalent--implies concentrations of carbon dioxide alone in the order of 350 to 400 parts per million, which can be compared to today's level of 380 parts per million.
So we're clearly not going to be able to meet this goal without some overshoot from which we will have to recover. In order to reach this two degrees Celsius goal, it's estimated that global greenhouse gas emissions would have to peak before 2015 and be at least 50% below current levels by 2050, the middle of the century.
Now, these are global numbers, and indeed achieving these low emission scenarios requires a comprehensive global mitigation effort.
The IPCC's fourth assessment report contains, in one of the chapters, some estimates of what this would mean for industrialized countries. Countries like Canada would need to reduce emissions by 2020 by somewhere between 20% and 40% below 1990 levels and in 2050 by approximately 60% to 95%. These ranges cover levels suggested in the bill under examination.
Emissions in developing countries, on the other hand, would also have to be reduced. They would have to start to be below the current business as usual emission pathways by 2020 and be substantially below this pathway by 2050. Scenarios with such global greenhouse gas emission reduction targets will require increased energy intensity and carbon intensity improvements of somewhere in the order of two to three times historical values.
Let me switch to the other end of the spectrum and talk about what we have to do now. Very simply, in my view, time is running out. What we do in the next decade or so will be critical to tackling the long-term threat of climate change. For example, the locking effects of infrastructure technology and product design choices that were made by industrialized countries in the post-Second World War period, when we had low energy prices, are responsible themselves for our current increases in greenhouse gas emissions.
Delaying decisions will seriously constrain opportunities to achieve future low emission levels and they will raise the risk of progressively more severe climate change impacts. It's been estimated that with each 10-year delay in a mitigation, it implies an additional 0.2 degrees to 0.3 degrees warming over a 100- to 400-year time horizon.
There is already, at the present time, an additional 0.6 degrees of additional warming in the bank because of our previous activities, so decisions to delay emission reductions are likely to be more costly and more risky.
To conclude, Mr. Chairman and members, let me quote from the speech by the chairman of the IPCC at this year's Davos meetings in Switzerland:
There would be dramatic loss of political power and influence for nations that stand unmoved by the growing global consensus for “deep cuts” in emissions of GHGs with a sense of urgency.
Thank you.