After years of warning the world about global warming and its dire consequences, Al Gore, the Nobel Prize winner, has finally taken the next, logical step. He is proposing a solution.

Mr. Gore has realized that conservation measures and "Cap and Trade" measures do not work. The world can be saved only, if we completely eliminate all carbon dioxide emissions during the next forty years.

Converting the electric power generating sector first, does make the most sense. All major technologies for generating electric power from renewable energy sources are in various stages of development. Installations using wind power, solar energy, geothermal heat, and marine power have been started up and are slowly gaining a measurable foothold.

At present, coal fired power plants generate the least expensive electricity. Therefore, market forces will never lead to the shutdown of the most egregious greenhouse gas emitters. Only legislative action can prevent the construction of any new, coal fired power plants.

We must also be aware that it will be very difficult to satisfy our growing electricity demand by building only windmill farms, solar plantations, and geothermal power plants. For many years to come, there will not be enough manufacturing capacity to build an adequate number of electric power plants using renewable energies. Initially, the capital costs of these plants will be high, risks for meeting rated output will be well above average, and elevated maintenance costs will be a common experience.

We also need to address a few unresolved technical issues. The most pressing one is the fact that both wind power and solar power can supply energy only on an interruptible basis. Electric power is a fleeting commodity and we have not yet developed technologies that are capable of storing large amounts of electric energy.

It seems unavoidable that nuclear power generation must assume a more substantial role during the next decades. Nuclear power has become safer and public resistance to nuclear power plants is slowly receding. Nuclear power plants can be installed faster once we begin to rely more on standardized reactor designs.

Nuclear reactors with smaller capacities need to be built as replacements for coal fired plant boilers. Huge amounts of capital and much time can be saved if existing coal plants can be retrofitted with steam produced in nuclear reactors to replace coal fired boilers. Steam turbines, generators, substations, administrative buildings, and cooling towers can continue their operation with only minor performance reductions.

This new type of reactor must be designed to be absolutely safe by installing both passive and redundant safety systems. Retrofit reactors should become available in a very few, standardized designs and in sizes that fit up with the predominant sizes of coal fired boilers in use.

While the US will be replacing, retrofitting, or shutting down its fossil fuel fired plants, it is an opportune time to prepare the US to regain its independence from foreign oil imports.

Very soon, such activity can save the US more than one trillion dollars annually. Past experience shows that petroleum prices and consumption of transportation fuels will maintain their unstoppable growths.

Ideally, the world will continue using its fleets of cars, trucks, trains, ships, and airplanes. Ideally, the world will keep its oil refineries operating and will preserve the huge distribution systems that deliver high quality liquid fuels to all corners of the world. Replacement of transportation fleets, oil refineries, and liquid fuel distribution systems will cost too much and may break the economies of even the richest countries.

We must realize that the world cannot live for more than a few weeks without transportation of foods, goods, and commodities. Famines, riots, and economic upheavals will become unavoidable consequences of the lack of plentiful and affordable transportation fuels.

To protect against such looming, economic disasters, the US must take the lead and learn how to produce petroleum substitutes from biomass. Recent events have taught us that we must never again abuse arable lands to make ethanol or diesel from food crops.

Instead, we must find plant species with very high energy contents and must grow these plants on arid and infertile lands. By using desalinated water and novel industrial farming techniques one can grow enough biomass to supply the entire world with transportation fuels for several centuries. Arid lands are abundant. Best of all, making petroleum substitutes from renewable biomass sources will not have to cost more than $50 per barrel.

Building plants for the domestic production of electric power and of transportation fuels from renewable energies will make the US strategically more secure, will make us economically stronger, will reduce global greenhouse gas emissions by one quarter, will create a huge number of jobs, and will pay for itself by producing large, domestic revenues for many decades to come.

The US must lead the world by example. No other country has the capabilities and the resources to rebuild its energy supply systems.