Actually, recently the news said that temperatures in Finland are rising more rapidly than in most of the globe. Mostly because we are located near the polar area, in between the Atlantic and Siberian climatic influences - so a slight change in any of those systems (polar, atlantic, siberian) is bound to affect us in many ways.

And, yes, sure the climate and the temperatures have been changing through the history, without any human influence. But this time it is just that the rise in temperatures is more rapid than ever. During millions of years all that oil was formed and got stored in pockets under ground. And now we have been drilling it up and burning a whole lot of it in just a century or so - causing a sudden and sharp rise in the amount of greenhouse gases in the atmosphere. So, sure the concentration of carbon dioxide has been naturally changing during the history of the planet. Now the mankind just makes the change happen extremely fast.

And as far as I understand, even people living in cities eat food produced by farmlands and fisheries. If farming and fishing becomes more unreliable because of unpredictable and extreme weather conditions, I'm afraid people will soon grow hungry...