People respond to incentives. When the cost of doing something goes up (perhaps the price of petrol goes up) they cut down on that activity (they switch to small cars, they drive less, they car-pool, they turn off the A/C when they don't need it). At the same time, alternatives become more attractive- alternative energy attracts more investment.
This may not apply to Global Warming, because the atmosphere is a commons- dumping CO2 into the air is effectively costless for each individual, so there is no incentive to do less.
However, a couple of stories in the Economist's Technology Quarterly make me hopeful.
One is about wave energy.The potential is huge
a report published earlier this year by the Carbon Trust, an organisation set up by the British government to help meet its targets for reducing greenhouse-gas emissions, concluded that 20% of Britain's electricity could be provided by wave and tidal power. This is four times more than previous estimates, and means that marine energy alone could enable Britain to reach its emissions-reduction targets. America, meanwhile, the Department of Energy's National Renewable Energy Laboratory has estimated that the use of wave power on the east coast could provide 10-25 times more electricity than the total wind potential of the Great Plains
Most produce electricity at a cost of between 10-20 pence (18-36 cents) per kilowatt hour (kWh), whereas electricity produced from natural gas costs around 4p/kWh.
Near Póvoa de Varzim, off the northern coast of Portugal, three 150-metre-long articulated snake-like pontoons, called Pelamis Wave Energy Converters, are in the final stages of being hooked up to the country's national grid...Each one has three power-converter modules distributed along its length, which transform the flexing motion at the snake's joints into electricity as the snakes are buffeted by the waves. The three snakes are the first stage of a planned 24-megawatt wave-power farm, which will be capable of providing 15,000 households with power. The Pelamis's design avoids the trade-off between resilience and efficiency by switching to a higher-efficiency mode in calm seas.
But the new device, called the Snapper, increases efficiency still further. Electrical generators tend to work most efficiently when a small force is applied at high speed—which is just the opposite of what wave power provides, says Ed Spooner, a consultant engineer based near Durham, in England, who invented the Snapper. His invention works much like a typical linear generator, in which a magnet is moved up and down inside coils of wire, inducing electrical currents in the process. But there is a crucial difference: alongside the coils are a second set of magnets of alternating polarity. These prevent the central magnet from moving up and down smoothly. Instead, magnetic forces repeatedly halt its motion, so that it moves up and down in a jerky fashion. The resulting series of short, rapid movements is more suitable for generating electricity than a slow, smooth movement. Early tests suggest that it could be as much as ten times more efficient than existing wave generators.
The other story is about hybrid cars like the Prius. These combine an Internal Combustion engine with a battery that never needs to be plugged in to the mains, because it draws its power from the engine. The Prius
achieves over 40 miles per gallon, perhaps 20% more than it would without hybridisation
One of them (Greg Hanssen of EnergyCS) has
replaced the original nickel-metal hydride (NiMH) battery with a higher-capacity lithium-ion battery, and has hacked the control software to prevent the petrol engine kicking in until the car is moving at high speed. As a result, his modified Prius can travel over 30 miles in all-electric mode, compared with a mile or so for a standard Prius.
studies by California's Air Resources Board confirm that generating the electricity to power cars in pure-electric mode produces only about half of the greenhouse gases of typical petrol vehicles. This assumes the power grid is half coal-fired, as America's is today. As the grid “decarbonises” over time, such emissions will fall.
Even when the petrol engine kicks in (as the master computer requires on all Prius cars at higher speeds), electric power is still blended in to improve fuel economy and provides up to 75% of the total power at 55mph.
All this efficiency need not be at the expense of power. Another pioneer is Andrew Frank, an engineering professor at the University of California at Davis.
Visitors to his lab today find a plug-in Ford Explorer sports-utility vehicle (SUV) equipped with a giant 16 kilowatt-hour (kWh) battery designed for long range—a conventional Prius battery has a capacity of 1.3kWh. He has replaced the original 3.5-litre internal-combustion engine with a frugal 1.9-litre version, thus boosting fuel economy, but the added kick from the electric motor means this SUV can still accelerate to 60mph faster than an ordinary Explorer. He has made similar modifications to a Mercury saloon, so it can travel 40 miles in all-electric mode and achieve an astounding 200mpg.
Bottomline: If we feel that CO2 is a major problem, raise the cost of throwing Co2 into the air- raise carbon taxes. Then, leave it up to the Engineers and Scientists. They have come through before.