Good morning.
Thank you for the opportunity to appear before you. Much of what I have to say is based on the fourth assessment report of the Intergovernmental Panel on Climate Change, the IPCC, although I will provide some updated information where it suggests that the need to act is becoming more urgent. My remarks focus on the long term and the immediate future.
Emissions of greenhouse gases continue to rise and are now growing at 3.5% per year. In fact, emissions for the last few years have been larger than the worst-case scenario developed by the IPCC in their Special Report on Emissions Scenarios in 2000. This worst-case scenario projects carbon dioxide concentrations in 2100 of almost four times pre-industrial levels with global temperatures around 4°C. We certainly don't want to go there. The impacts could be catastrophic.
Atmospheric concentrations of greenhouse gases are indeed continuing to grow. Currently, the concentration of carbon dioxide—the most important greenhouse gas—is almost 390 parts per million, which is a 38% increase since pre-industrial times and the highest it has been in almost one million years. The annual rate in increase in the 1990s was about 1.5% per year; it is now close to 2.5%. This carbon dioxide will stay in the atmosphere for many centuries. As it does, it will continue to trap heat and warm the planet.
As a result of these changes, global average temperatures have risen. Global average temperatures are now outside the range observed over the last 1,300 years. The last time the polar regions were significantly warmer than at present for an extended period, there was little ice at the poles, and sea levels were four to six metres higher. What is more troubling is that the linear warming trend over the last 50 years is nearly twice that for the last 100 years. In other words, the closer one comes to the present, the more the rate of increase of global temperatures increases.
There are other indications that climate change may be accelerating. Closer to home—I'm sure Louis Fortier will elaborate—the Arctic sea ice is declining faster than any of our models has been projecting. The reduction in 2007 was unprecedented in the period for which we have reliable, comprehensive measurements. In some estimations, late summer Arctic sea ice could disappear almost entirely within the next few decades rather than by the end of the century, as was previously thought. The ice sheets in Greenland and Antarctica are melting faster than we have seen before, and we have been forced to entirely rethink our understanding of glacier physics. As a result, current projections of sea level rise are as much as twice that reported in the IPCC's fourth assessment report.
All of this suggests to me that we have to act, and act urgently, to address the threat of climate change. Time is not on our side. An explicit long-term goal is regarded as being absolutely essential. Without such a goal, none of us—individuals, businesses, and other levels of government—will have a clear direction for policy and action. Such a goal must be strong enough to stimulate the necessary ambition.
But this is not enough. We also need short- and medium-term objectives. Once each short-term objective is achieved, decisions on subsequent steps can be made in the light of new knowledge and reduced uncertainties.
Ideally, the choice of a long-term goal is the product of solid science and wise political decision-making. Science can inform the process, but in the end it depends on what we value, and this is best determined through a political process.
It is estimated that if we stabilized concentrations of all greenhouse gases in the atmosphere at roughly the equivalent of 450 parts per million of carbon dioxide, we could limit global mean temperature increases to about 2°C above pre-industrial levels.
Such a stabilization level, however, implies concentrations of carbon dioxide alone of 350 to 400 parts per million, which has to be compared with today's level of 390 parts per million. Clearly it's going to be difficult now to meet this goal without some overshoot from which we will have to recover.
There is a growing consensus that indeed we should try to avoid such an increase of 2°C above pre-industrial levels, in order to avoid what the framework convention refers to as “dangerous interference with the climate”. We have already seen an increase of 0.7°C, and in order to achieve this goal it is estimated that global greenhouse gas emissions will have to peak before 2015 and be at least at 50% of current levels by 2050.
These are global numbers, and achieving these low-emission scenarios requires a comprehensive global mitigation effort. The IPCC's Fourth Assessment Report contains some estimates of what this would possibly mean for industrialized countries. Countries like Canada will need to reduce their emissions in 2020 by 25% to 40% below 1990 levels and in 2050 by approximately 80% to 95%. These ranges cover the levels suggested in Bill C-311. Emissions in developing countries, on the other hand, would need to start to be below their current business-as-usual emissions pathways by 2020 and be substantially below these pathways by 2050. Such a commitment was made recently by the Chinese premier, at the United Nations meeting on climate change in New York.
Now let me switch briefly to the other end of the spectrum and talk about what we have to do now.
Very simply, 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. Decisions to delay emission reductions will likely be more costly and riskier. Delaying decisions will seriously constrain opportunities to achieve future low stabilization levels and raise the risk of progressively more severe climate change impacts.
It's been estimated that each 10-year delay in mitigation implies an additional 0.2°C to 0.3°C of warming over the next 100 to 400 years. Because of the inertia of the climate system, there is at present already approximately 0.6°C of additional warming, as it were, in the bank. Together with the warming we've already experienced of 0.7°C, this gets us perilously close already to the 2°C target.
As the IPCC has stated, evidence of climate change is unequivocal. The scientific community has issued a warning, a warning that may now be underestimated. Addressing climate change will be a long-term challenge, but one we must start addressing now. There is no excuse for inaction. The climate has a memory, and it will not let us forget.
To conclude, let me quote from the World Development Report 2010 issued recently by the World Bank, which says we need to “act now, act together, and act differently”.
Thank you.