There are problems with this... acidic rain dissolves carbonates in the rocks. Also oil also produces sulphur dioxide and makes the rain even more acidic, though moves are being taken to try to scrub the sulphur from emissions. (There is another problem with this too in that the sulphate particles reflect more radiation from the sun, so the global warming effect has been suppressed somewhat - once we take the sulphur away, then the real situation emerges.)

The ocean has been absorbing the excess CO2 that we've been pumping out over the last couple of hundred years and its capacity to absorb more is diminishing. It is a system that has been in equilibrium for millennia, but that equilibrium can shift and is vulnerable to positive feedback as temperature rises.

So, as less CO2 is being absorbed more accumulates in the atmosphere, as observed over the last few decades, and accelerating.

As the CO2 concentration increases then so does the average temperature of the Earth, including the oceans. As a result, water's ability to hold dissolved gases decreases, so it becomes less efficient as a sink. Therefore there is a danger that the oceans will not be able to absorb any more CO2. If temperatures rise even further, perhaps the oceans could even release the CO2 back to the atmosphere.

Also, this is bad news for the critters that fix the dissolved CO2 and make carbonates. As sea water becomes more acidic the reaction becomes more difficult. You all know what happens when you add tartaric acid to bicarbonate of soda... Carbonates do not like acidity.

Of course, the variations in pH are tiny, but significant to the creatures that depend on a stable environment. Temperatures are much more significant, however.

We can cope with 60 degree or more temperature differences by sweating, adjusting thickness of clothes, using air conditioning and burning fuel, but creatures in the ocean are extremely dependent on temperatures. Their enzymes, life and genetic processes are finely tuned to operate at certain temperatures, and this range is narrow. They have to live in the range of temperatures that they have evolved to cope with, or die, and this can affect the whole food chain with big implications for our food supply.

We may not think of a 1C or 4C increase in temperature as such a big deal, but if our body core temperature changes by a couple of degrees we don't feel well at all. A 4C rise is a medical emergency and 6C rise almost certainly fatal.

Thus it seems appropriate to think of our planet "having a temperature", but how do we cure it? It isn't as easy as taking an aspirin or a cold bath, but it will hurt more in the future if too little is done now.

Andy.