Global efforts to cope with climate change

Jeffrey D. Sachs, Project Syndicate

The 10 warmest years on record have all occurred since 1990, and 2005 is likely to be the warmest ever. This year, we've gotten a taste of the many kinds of dangers that lie ahead: More extreme hurricanes, massive droughts, forest fires, spreading infectious diseases, and floods. The climate is changing, and more is yet to come.

The world's governments will meet in Montreal at the end of November to plot the next steps, including specific measures that the world could adopt if the Bush administration abandoned its willful neglect of this critical issue.

Climate change is equated with "global warming," but much more than warming is involved. The rising concentration of carbon dioxide and other greenhouse gases is leading to more extreme storms, higher-intensity hurricanes, rising ocean levels, melting glaciers and ice sheets, droughts, floods and other climate changes. Even the chemistry of the land and ocean is changing, with the ocean becoming more acidic -- thus threatening coral reefs -- as a result of higher carbon dioxide.

The specific patterns of change are not known precisely, but the risks of continuing on our current global course are widely appreciated. Yet the United States has refused to sign the Kyoto Protocol, which does little to change the long-term course of events on the planet, since it calls for only small steps up to the year 2012.

Under the terms of the UN treaty on climate change, the signatories -- virtually the whole world -- are to gather each year to discuss the treaty's implementation. The conference in Montreal -- the 11th such meeting -- should look beyond 2012, so that the world gets onto a safe and sustainable long-term climate path.

The actions that are needed are difficult to introduce, because they go to the heart of the worlds use of energy, particularly its use of fossil fuels (coal, oil, and gas), which, when burned, release carbon dioxide -- the key source of rising greenhouse gases -- into the atmosphere. Yet the world economy depends on fossil fuels, and developing countries will need to use more, not less, of them as their economies grow. Even if the world runs out of oil and gas in the coming years, coal will prove to be plentiful, and solid coal can be converted at relatively low cost to liquid fuels for automobiles and other uses.

Unfortunately, clean, renewable energy sources that do not emit carbon dioxide, such as wind power and geothermal power, are not yet sufficient. Solar power can be produced on the required scale but is too expensive under current technologies. Nuclear power is relatively cheap, and could be plentiful, but poses huge dangers for increased proliferation of nuclear-weapons materials.

So: Fossil fuels are plentiful, but harmful; renewable sources like wind are good for the climate but not plentiful. Solar power is plentiful but not cheap. Nuclear power is plentiful but not safe.

Improved technologies can offer a way out of this bind, but only if we think and act ahead. There are two main kinds of technologies that look most promising. The first is energy conservation through more fuel-efficient vehicles. New hybrid automobiles, pioneered by Toyota, use both gasoline and electric power to boost gasoline efficiency by approximately two-fold. A massive changeover to more fuel-efficient vehicles would make a big difference, especially as the numbers of vehicles on the road soars in China, India, and other developing countries.

The second big technology that could make a major difference is called "carbon capture and storage." The idea is to "capture" the carbon dioxide that is emitted in power plants and other big factories when fossil fuels are burned, thereby preventing it from entering the atmosphere. The captured carbon is then pumped into underground storage sites such as empty oil fields and other suitable locations.

All of the key aspects of the technology -- capturing the carbon dioxide, putting it into pipelines for shipment, and then depositing it underground -- have already been demonstrated, but they have not yet been tried, and proven, on a large scale. There is strong evidence, however, that it would not cost the world huge amounts to undertake large-scale carbon capture and storage.

The problem is timing. The changeover of the world's vehicles to hybrid and other efficient technologies will take decades, not years. So will the changeover of power plants to carbon capture and storage. If we procrastinate, the dangers posed by climate change will confront us as we talk, debate, and plan. The world needs to start acting soon -- very soon -- if it is to head off the major threats.

All major regions of the world will need to be involved. Today's developing countries are not yet major emitters of carbon dioxide, but with economic growth they will become so. Therefore, all countries, both developed and developing, need to do their part, with rich countries helping poor countries cover the financial costs of adjustment.

Plenty of carbon dioxide will be emitted into the atmosphere as the world's climate negotiators fly to and from the Montreal meeting. Let's press our governments to make real progress when they meet; otherwise they will merely be adding to the problem.

Jeffrey Sachs is Professor of Economics and Director of the Earth Institute at Columbia University.