freediver wrote on Jun 7^th, 2008 at 9:53am:


What did you mean by this then? I assume it mean't the price of petrol.

This article suggest we are not going to run out of oil anytime soon. Also that it will be difficult to replace it as a transport fuel, even with carbon taxes. This is as opposed to electricity generation which is fairly easy to replace with low emission technologies:

http://money.ninemsn.com.au/article.aspx?id=576470

IEA calls for energy 'revolution'

By Ed Crooks in London , Financial Times, 6 Jun 2008

The good news in the International Energy Agency's report on the future of energy technologies is that there is enough oil left on the planet to allow a huge increase in consumption over the next few decades.

The bad news is that the consequences for the climate of burning that much oil would be alarming.

The IEA, the rich countries' energy watchdog, is urging the world to start weaning itself off oil, not because supplies are running out but to avoid "significant change in all aspects of life and irreversible change in the natural environment" as a result of global warming.

In the IEA's business as usual "baseline" scenario, oil demand rises from its present level of 87m barrels a day to 135m b/d by 2050. The projection is a robust rejection of the argument, increasingly prevalent as the price of oil has soared, that global oil production is at or near its peak.

The IEA accepts that meeting this sharply increased demand would require massive investment, especially in the Middle East, and "conventional" oil would provide at most about 92m b/d. The rest would come from "unconventional" sources such as oil sands, shale oil and Arctic oil, and liquid fuels made from coal and natural gas. Biofuels would also make some "limited" contribution.

However, if there is a "global energy technology revolution", the IEA believes, global oil demand could be cut sharply, dropping 27 per cent from present levels. Greater fuel efficiency in motor vehicles, greater production of biofuels, and some use of electric and hydrogen-fuelled transport would all contribute to curbing oil demand.

In that scenario, the world's carbon dioxide emissions could be halved from 2005 levels by 2050, and oil-consuming countries' dependence on potentially unstable oil-producing regions would be diminished.

The problem is that it is very hard to replace oil as a transport fuel. Electricity generation can be made low-carbon relatively easily, with nuclear power and wind farms, which are in use today, and carbon capture and storage at fossil fuel power plants, which can be done by integrating currently available technologies.The flexibility of oil-derived fuels for road and air transport is much more difficult to replace.

Cutting emissions from power generation and taking other relatively low-cost measures could mean global carbon dioxide emissions peaking during 2020-30, then falling back to current levels by 2050, the IEA believes.


"Those extra bits of carbon dioxide are so expensive to squeeze out," says Cecilia Tam of the IEA, one of the report's authors.

"When you look at transport, you need new technologies that are really not available today."

To make those technologies cost-effective, the IEA suggests, emissions would need to be priced at $500 a tonne of carbon dioxide, a huge increase from today's levels. Even with technological improvements, the price might need to be $200 a tonne.

Nobuo Tanaka, the IEA's executive director, said in Tokyo on Friday that the energy technology revolution was "both necessary and achievable", but accepted it would be a "tough challenge". Persuading consumers and voters to accept emissions prices in the hundreds of dollars will be one of the most daunting aspects of that challenge.

Yes PJ, that's what I meant.

The reported efficiencies are not that different. Obviously hilly country is going to be where the biggest difference is.

Now you're comparing petrol to diesel?

1. You need to factor in the price difference (20% more than petrol), or at least the difference in calorific value. Diesel produces more energy per litre than petrol. (38.7 as against 34.2MJ/L)

2. Combusting 1 litre of diesel produces 13% more CO2 than combusting 1 litre of petrol (although you could use biodiesel), and then;

3. By manufacturing hybrids, you get to develop the technology for full-blown electric vehicles. The new generation hybrids due to come out around 2010 (according to the word that's out) are set to half fuel consumption again.

By the way, I get 3.6L/100km with Freeway driving of that kind.

muso wrote on Jun 8^th, 2008 at 7:19pm:



Yes that true but only because you get more power out of one litre of diesel - so more mileage. Then you have to factor in that diesel engines are inherently more efficient. Taken all together diesel engines emit less CO2 than petrol ones:

http://en.wikipedia.org/wiki/Diesel

Diesel-powered cars generally have a better fuel economy than equivalent gasoline engines and produce less greenhouse gas pollution. Their greater economy is due to the higher energy per-litre content of diesel fuel and the intrinsic efficiency of the diesel engine. While petrodiesel's 15% higher density results in 15% higher greenhouse gas emissions per litre compared to gasoline,[5] the 20–40% better fuel economy achieved by modern diesel-engined automobiles offsets the higher-per-liter emissions of greenhouse gases, and produces 10-20 percent less GHG emissions than comparable gasoline vehicles.[6][7][8] However, the EPA carbon footprint estimates do not include the carbon cost of vehicle manufacture, nor the carbon cost of filtering particulates, sulfates, and nitrates emissions. Biodiesel-powered diesel engines offer substantially improved emission reductions compared to petro-diesel or gasoline-powered engines, while retaining most of the fuel economy advantages over conventional gasoline-powered automobiles.

http://news.smh.com.au/world/japan-pm-set-to-unveil-action-on-climate-20080609-2nv7.html

Japanese Prime Minister Yasuo Fukuda is expected to unveil a plan to force industry to cut carbon emissions in a bid to step up the fight against global warming despite resistance from the business community.

In a speech scheduled later in the day at the Japan National Press Club, Fukuda will likely announce a self-imposed target of cutting greenhouse gas emissions by 60 to 80 per cent by 2050, according to media reports.

He is expected to support a so-called "cap-and-trade" system which would require major businesses to reduce carbon emissions while creating an economic incentive by allowing the trade of emissions credits.

Fukuda's announcement is aimed at showing his determination in the global battle against climate change before he hosts the July 7-9 G8 summit, where global warming will be a key issue.

UN scientists who shared last year's Nobel Peace Prize warned that unless human-made climate change is halted, the world risks more natural disasters and droughts, putting millions of people at risk.