[LINK] 'Smart' cars as fuel-efficient as hybrids

[Chris Maltby]

On Wed, May 16, 2007 at 11:54:31AM +1000, Ivan Trundle wrote:
> Methane contributes more to the overall greenhouse gas potential  
> since each kg of methane warms the Earth 23 times as much as the same  
> mass of CO2 over a 100-year period (though there is currently 220  
> times more CO2 in the atmosphere than CH4). Methane has a large  
> effect for a brief period (about 10 years), whereas carbon dioxide  
> has a small effect for a long period (over 100 years).

Ian is right about the impact of additional methane from sheep and
cattle meat production - though it's not a new problem. The concern
is hightened by the potential for crossing new climate change tipping
points, so every bit of short term heat retention that can be reduced
is important. But we need to be looking beyond 10 or even 100 years.

The oceans dissolve atmospheric CO2 - and there's a lot more ocean than
atmosphere, but it's not a permanent CO2 store, and increased dissolved
CO2 will bring its own problems.  As I understand, it seems that the
fastest genuine carbon sink is the formation of limestone rock in the
oceans from the accumulation of calcium carbonate in the shells of
marine organisms, including corals. They'll take a lot longer than 100
years to deal with the CO2 we're dumping into the atmosphere now.

Chris