It's not in dispute that high CO2 levels in the atmosphere are correlated with high temperatures - just look at Earth's more distant history, or at Venus. Nor that CO2 levels have risen very fast in the last century, and that this is definitely due to human action.

On the other hand it is true that the rapid increases of the global average temperature in the '90s in particular have been replaced by a sort-of stagnation, while CO2 emission levels haven't slowed, so there is clearly more going on. And the simple fact that CO2 levels have been considerably higher still than today in various earlier periods, proves clearly enough that the Earth is quite capable of huge climate fluctuations without any human interference. But what a lot of people forget is that just because Earth is unlikely to be in any way permanently scarred by all those CO2 emissions and all that other pollution now, doesn't mean that the same can be said for mankind. Whatever mechanism is slowing down the temperature increase at the moment, sooner or later it will resume if CO2 emissions aren't scaled back dramatically. Or even if they are. Sure, science is also evolving fast, and perhaps it can limit the damage for mankind, but in poor countries especially, such solutions may be too expensive to avoid a deterioration in living standards.

And your article is just plain lying in the bit where it mentions that "the ice caps aren't melting". In Antarctica it's complex and there is no mass melting, sure. But in the Arctic it's very clear and very fast - and even the ancient Egyptians already knew that white surfaces (like ice) reflect more sunlight and hence keep things cooler than dark ones (like sea water) do, so the disappearance of the Arctic ice cap would further accelerate global heating.

A last point is that a significant part of all those sums spent on fighting climate change does serve other, less disputed purposes too. Like getting closer to energy independence, say, or simply the increased ability of mankind to get its energy from inexhaustible sources like sunlight, tidal energy and wind, rather than exhaustible ones like fossil fuels (even if the advances of science keep unlocking new reserves, the reserves are still not infinite and consumption in the developing world is rising awfully fast).