Earth's climate has undergone dramatic changes in the past. That fact may be influencing many intelligent people who are trying to assess what is going on with "climate change." The fact is that present changes in Earth's climate are different in causation and create unprecedented risks.

Analysis of Antarctic ice cores shows consistent temperature cycles on Earth, each major cycle taking around 100,000 years. The records go back over 500 million years. These cycles are associated with variations in the Earth's orbit around the Sun. Carbon dioxide concentrations have followed similar cycles but as they are shown to follow, not lead, the temperature cycle.

Average temperatures on Earth have been increasing in recent decades. Why? This increase cannot be explained by natural cycles; the most likely culprit is man-made emissions of so-called "greenhouse gases." Ongoing emissions are estimated, by the United Nations Intergovernmental Panel on Climate Change, to increase surface temperatures by a further 2 to 4 degrees by the end of the century. Earth is now likely to be entering climatic conditions never before experienced in recorded history.

There may be benefits from warming. But the risks and costs of those outweigh benefits by far.


What are the risks? First, there is likely to be more extreme weather events - major storms, hurricanes, floods, droughts, winds and wildfires. These which will threaten lives, property and normal economic and social activities. Second, the rising sea level (due to melting snow or ice cover of land and to the expansion of sea water) will threaten lives, property and activity in coastal areas. Coastal areas can include New York City, edges of island countries around the globe, parts of Asia such as Bangladesh, and other low-lying areas.

It is also possible that there will be a spread of diseases associated with warmer, wetter conditions. Ecosystems may also change. The system of ocean currents might change, such as a weakening of the Gulf Stream, which would cause climatic change for millions of people in Europe, including Great Britain. The permafrost in high northern latitudes might melt, releasing large amounts of methane gas, accelerating the whole process of global warming. At the extreme, there is the catastrophic, although remote, risk of a runaway greenhouse effect of the kind that created the conditions on Venus and which could destroy life as we know it.

As we have never before experienced the present level of greenhouse gas concentrations, let alone the concentrations forecasted for the foreseeable future, we cannot dismiss these risks.

Controlling climate change, while a challenge, could help global economies. Examples of methods of control include adopting efficient energy technologies such as (1) using modern four cylinder turbo-diesel engines and modern 2 liter gasoline engines in automobiles and light trucks, (2) using technologies such as LEDs in lighting, (3) switching from coal to natural gas in electricity generation, and (4) adopting heat pumps for space conditioning. Our research institutions around the world can come up with hundreds of other methods.

The benefits of doing nothing are minimal while the costs are high and the risks are enormous. The case for taking effective action is overwhelming. Can America lead the effort to mitigate climate change? What sort of policies would work? Regulations, such as in building codes and new car standards, have their place but the most effective policies are those that use the market mechanism. The latter will be assisted by appropriate taxation. If you increase the price of contributing to climate change, people will move to other ways of doing things. Examples are taxes on fuel-inefficient new cars and taxes on carbon emissions. These taxes would also help deal with the problem of the federal deficit.

Addressing the skeptics of climate change: suppose that our scientists are all wrong. There is no warming of Earth due to man-made causes. Would it still not be wise to move forward and learn how we can influence the climate? That can help counteract the effects of future natural climate change. So for you, the issue should be not whether mankind is creating climate change, but whether mankind can control the Earth's climate. You can definitely push for that in your political efforts.

Our democratic institutions are not well suited to making difficult decisions. We are used to making vital decisions only by the time matters reach the critical stage. In the case of climate change, the stakes are so high, action today is needed. We have nothing to lose by moving ahead with activities that will help us learn how to control climate change. But governments are not doing enough. Citizen involvement is essential. Make your vote count by investing in the technology that you believe will help us control our climate. We have only this Earth to live on -- we all share it -- our resources like water and air are finite. We also have a responsibility toward our children and theirs.

Edward A. Hudson works in New Zealand as a consultant to government and business on technology. Robert Dullien is a U.S.-based mentor to technology-based companies and government.