On a millennium scale level an increase in global temperatures has been occurring for about 15,000 years (give or take), since the start of the last interglacial. On a century scale level temperatures have been increasing for about 150 years, since the end of the Little Ice Age. On a decadal level temperatures have been increasing since the great "Global Cooling" scare of the 1970s.

So it should be no surprise, then, that right now temps may be a bit on the warm side, comparatively speaking. This situation might be quite inconvenient for us, though.