Arnold Schwarzenegger: It's not a time for talk. It's a time for action

The Terminator: There's no doubt about the science. Now we must all gear our economies to take on global warming

During the past 18 months, we created the 25 million-acre Sierra Nevada Conservancy, the largest conservancy in the nation; we opened the path to the Hydrogen Highway, which will encourage the building of hydrogen fuelling stations and the use of hydrogen-fuelled vehicles; we sponsored the first Ocean Protection Act in the nation to protect and restore our ocean resources; and we secured permanent funding to reduce emissions from dirty engines and equipment.

In addition, with our Green Building Initiative, we have put the biggest user of electricity in California - the state government itself - on an energy diet. By requiring new state buildings to use the latest environmentally friendly and energy efficient design and construction methods, we will reduce electricity and water use by more than 20 per cent in our state-owned facilities.

Now it is time for Californians to seriously address the issue of climate change and its potential to create havoc with our environment and economy. The debate is over. We know the science. We see the threat posed by changes in our climate. And we know the time for action is now.

I launched our effort when California hosted the United Nations World Environment Day Conference in San Francisco last month, where leaders from around the world gathered to discuss our shared responsibility for protecting the earth. It was there that I signed an executive order to establish clear and ambitious goals to reduce greenhouse gas emissions in our state: by the year 2010 our goal is to reduce our emissions to less than those we produced in 2000; by 2020 our goal is to make our emissions lower than 1990 levels; and by 2050 our goal is to reduce overall emissions to a full 80 per cent below those we produced in 1990.

Greenhouse gases are emitted from every sector of the economy, and these pollutants blanket the globe, trapping heat and creating the "greenhouse" effect, often referred to as global warming. Global warming threatens California's water supply, public health, agriculture, coastlines and forests - our entire economy and way of life. We have no choice but to take action to reduce greenhouse gas emissions.

In order to achieve our goals, we are implementing California's landmark greenhouse gas law, which requires lower-emitting vehicles to be sold in our state, starting in 2009. We are accelerating the timetable to get more energy from renewable resources, such as wind, solar, geo-thermal and bio-mass conversion to 20 per cent by 2010 and 33 per cent by 2020. We have implemented the world's most stringent appliance and building efficiency standards. We are aggressively pursuing with the legislature my proposal to have one million solar-powered homes and buildings in California to save energy and reduce pollution. We are greening the state's fleet of government vehicles, to be the most fuel-efficient in the world.

These steps are great for the environment and great for our economy, too. Many people have falsely assumed that you have to choose between protecting the environment and protecting the economy. Nothing could be further from the truth. In California, we will do both.

That is why I am travelling around the state and my administration is holding a series of conservation summits for businesses around California, spreading the word that pollution reduction is good.

Pollution reduction has long been a money saver for businesses. It lowers operating costs, raises profits and creates new and expanded markets for environmental technology.

Many private businesses in California are cutting greenhouse gas emissions by simply improving efficiency. Others are also implementing cutting-edge hydrogen fuel technologies, installing advanced solar power systems and constructing environmentally friendly buildings.

And best of all, many California companies are participating in the public and private partnerships that are being formed with the state and some of our leading universities and research centres to find innovative means to create a cleaner and healthier environment.

All of these environmental technologies will allow us to conserve energy, cut pollution, protect our natural resources and create jobs for Californians. We must all accept the challenge to protect our environment. In California, I am pleased that we are once again providing leadership in this critical area. We understand that in this world in which we live, our actions sometimes have unintended consequences for our land, air and water. As John Muir, an immigrant from your islands who launched America's conservation movement here in California, once said: "When one tugs at a single thing in nature he finds it attached to the rest of the world." I ask citizens and governments everywhere to do their part by conserving energy, reducing the use of fossil fuels, reducing waste and taking every opportunity to work together for a cleaner, healthier tomorrow. It is not enough for us to be just caretakers of the world that we have been given, we must leave it a better place for future generations.

This is our duty to those who share this world with us and to those who follow us.

Arnold Schwarzenegger is Governor of California