1 degree C in 100 years is an increase on 2004 average temperature (14.6) of 6.8%.?

Yeah that's a valid point. Another to consider - from the lowest point in the last ice age to the present was just an 8°C temperature change.

http://en.wikipedia.org/wiki/Image:Ice_Age_Tempera...

The planet just doesn't go through very large temperature changes, but a small change can make a big difference in the global climate.

Perhaps we will notice, but that is just a theory. The climate has been warmer in the recent past, and the natural world seemed to survive just find. Every plant you see evolved in an environment with global temperatures several degrees warmer than present, and CO2 levels much higher.

In nature many things are very finely balanced. A small change in temperature - warmer or cooler - can have a huge impact on the weather, ecology, climate etc.

Whilst there are certainly some benefits of a warmer climate there are many more negative consequences, especially for thoise species that are unable to adapt or evolve.

Historically, temperature changes were much slower than they are now and things had more time to adapt to changing temperatures. Today the rate of change is outpacing the rate of evolution or adaptation. As humans we're very lucky in that we're highly adaptable and as such, can mitigate many of the effects of a warmer climate.

Although temps have risen approx 100°C in 100 years, most of this rise has occured in recent decades. Here's the average temps...

2000's - 14.5304°C

1990's - 14.3207°C

1980's - 14.1686°C

1970's - 13.9641°C

Decadal temp anomalies since 1850 can be found here http://profend.com/gtr/tables/decavepage.html and in graph form here http://profend.com/gtr/graphs/decgraphave.html

PS, in percentage terms the temperature change is 0.348% (the Celsius scale is relative not absolute, you need to use Kelvin or Rankine in which case the average global temp is 287.75K)

Even one degree increase could result in a great change in climate, many animals that will not be able to adapt will go extinct, and the sea level will rise and floods would be more disastrous.