Daniel Patrick Moynihan once said: "You are entitled to your own opinion but you are not entitled to your own facts."
This simple statement is important in any discussion of climate change. We can argue endlessly about what the facts mean but no one is entitled to deny the facts.
That, of course, does not stop people from trying. Or pulling out one fact from a thousand and claiming it is the only true fact. Or from reading scientific articles which provide dissenting opinions and holding them up as the only truth.
Science does not have all of the answer but scientists are trying to find the answer as quickly as they can. It is hard work.
It requires time. It is expensive. And it doesn't fit within our modern 24 hour news cycle paradigm nor within the four year time window for elected politicians.
That said, the simple facts about climate change are based on our scientific understanding of the way matter interacts with electromagnetic radiation.
Visible light excites electrons within molecules. It causes ground state electrons to jump to excited states. This results in the absorption of energy.
This energy can be dissipated in a number of ways but the most common is through "thermal deactivation."
Molecules jiggle and wiggle giving off heat, in the form of infrared radiation, to their surroundings. Heat causes molecules to vibrate and vice versa.
We know this for a fact. It can be demonstrated in many ways. It is why we know that incoming light from the Sun can pass through the gases in the atmosphere without significantly heating it up and why re-radiated heat from the planet's surface is captured by gases in the atmosphere.
We also know that certain molecules, such as water and carbon dioxide, are particularly efficient at capturing the heat given off by the surface of the Earth. Using an infrared spectrometer, we can measure the infrared spectrum of all of the gases in the atmosphere. We can find out exactly how opaque or transparent the atmosphere is at these wavelengths of light.
It is a fact that we can measure the atmosphere's ability to capture heat.
We also know beyond a shadow of a doubt that carbon dioxide levels in the atmosphere have increased significantly over the past century. We have been making direct measurements in various locations for the past 70 years and indirect measures using modern instrumentation for even longer.
There is no denying the fact that sunlight enters the atmosphere, warms the surface of the Earth, is degraded to heat, which is ultimately radiated back into space but is intercepted in the atmosphere by greenhouse gases on its way out and the rate at which this process occurs controls the mean surface temperature of the planet.
To a scientist, this means that changing the levels of carbon dioxide in the atmosphere will change the rate of heat transfer and, in turn, alter the surface temperature. The empirical evidence is provided by the historical record where we see increasing levels of carbon dioxide correlated with increasing temperatures. We also see decreasing levels of carbon dioxide correlated with temperature minimums.
Those are the facts.
Of course, they are open to interpretation. Some people would like us to believe that while carbon dioxide levels in the atmosphere are increasing, it is nothing to do with us. I suspect they are the same people that would look at their mothers after spilling milk and say: "I didn't do it."
There are others who would like us to believe increased carbon dioxide and other greenhouse gas concentrations are a consequence of climate change and not the result.
There are some individuals who take the fatalistic view stating that climate change is inevitable so why do anything about it? After all, in the history of our planet, the climate has varied many times and often for reasons we don't understand.
But the vast majority of scientists look at the facts and worry about the impact of climate change.
The Harper Conservatives, on the other hand, don't seem to want to do anything. They have set a weak target for Canada's contribution to controlling greenhouse gas emissions. Indeed, our target seems to be the weakest in all of the G7 according to some environmental groups.
Yet, Minister Aglukkaq said: "This target is fair and ambitious, an ambitious commitment based on our national circumstances, which includes a growing population, a diversified growing economy, and Canada's position as a world leader in clean-electricity generation."
The Conservative government has once again left us as the laggards in an effort to address this important global issue. But perhaps that is not surprising. After all, as a politician, if you can't get the facts to support your position then the next best thing is to ignore them.
