With days at their shortest and nights at their longest across the Northern Hemisphere, the worst of winter weather is setting in from Alberta to Germany. With the snowstorms and deep freezes come the inevitable climate change jokes: "Looks like global warming decided to take the day off, eh?"

The simplemindedness of the statement aside, a small but vocal minority have been pressing the case that the positive effects of global warming may offset the negative impacts.

Though it sounds utterly ridiculous, there's no overlooking that current climate patterns are not necessarily "perfect". On a geologic time scale, climates change frequently as continents shift. Warmer and milder conditions during the winter could save 40,000 deaths in the United States alone, and probably well above that in less-developed countries outside the tropical regions. Warmer weather could also reduce the economic problems caused by snowfall and snow removal in urban areas.

Growing seasons in many areas would likewise be expanded, allowing for increased crop yields and a larger world food supply. While coastal areas might be lost, the area in extreme northern and southern nations brought out of polar conditions would more than make up for the lost area.

While tempting, especially on cold days, these arguments have all be present and thoroughly refuted by the IPCC, a group convened to thoroughly study and evaluate the effects of a changing climate on the world. After finding beyond a reasonable doubt that humans are responsible for the warming climate, the IPCC also found that any potential benefits are vastly outweighed [PDF] by lost rainfall, changing soil conditions and flooded urban areas.

And even before any major climatic effect is evident, global warming will almost certainly aggravate existing geopolitical conflicts, and instigate new ones. Competition for newly accessible resources at the poles, and increased competition over diminishing ones in the tropics could lead to human losses well in excess of the lives saved by warmer conditions. So while it's unfair to say that global warming has no benefit to humanity, it's clear that when costs and benefits are laid out an analyzed, the end result of climate change is unquestionably destructive.