These days, most nature photographers are deeply committed to the environmental message.

When we tune in to an especially human way of viewing the landscape powerfully, it resonates with an audience.

The combination of pictures and words together can be really effective, and I began to realise in my career that unless I wrote my own words, then my message was diluted.

A lot of people think that when you have grand scenery, such as you have in Yosemite, that photography must be easy.

I began taking pictures in the natural world to be able to show people what I was experiencing when I climbed and explored in Yosemite in the High Sierra.

I think landscape photography in general is somewhat undervalued.

I almost never set out to photograph a landscape, nor do I think of my camera as a means of recording a mountain or an animal unless I absolutely need a 'record shot'. My first thought is always of light.

There is no question that photography has played a major role in the environmental movement.

I find it some of the hardest photography and the most challenging photography I've ever done. It's a real challenge to work with the natural features and the natural light.

The reason that I keep writing is that all my most powerful messages about the fates of wild places that I care about need to have words as well as images.

Today, I'm very careful not to mention very specific locations when I write or give captions.

I began to realise that film sees the world differently than the human eye, and that sometimes those differences can make a photograph more powerful than what you actually observed.

Wanting to take a light camera with me when I climb or do mountain runs has kept me using exclusively 35 mm.

I like to feel that all my best photographs had strong personal visions and that a photograph that doesn't have a personal vision or doesn't communicate emotion fails.

What I mean by photographing as a participant rather than observer is that I'm not only involved directly with some of the activities that I photograph, such as mountain climbing, but even when I'm not I have the philosophy that my mind and body are part of the natural world.

My mountaineering skills are not important to my best photographs, but they do add a component to my work that is definitely a bit different than that of most photographers.

There's no question that photographs communicate more instantly and powerfully than words do, but if you want to communicate a complex concept clearly, you need words, too.

If we limit our vision to the real world, we will forever be fighting on the minus side of things, working only too make our photographs equal to what we see out there, but no better.

My first thought is always of light.

And most of my early pictures failed but about one in a 100 somehow looked better than what I saw.

Ever since the 1860s when photographers travelled the American West and brought photographs of scenic wonders back to the people on the East Coast of America we have had a North American tradition of landscape photography used for the environment.

I'm exchanging molecules every 30 days with the natural world and in a spiritual sense I know I am a part of it and take my photographs from that emotional feeling within me, rather than from an emotional distance as a spectator.

I remember when an editor at the National Geographic promised to run about a dozen of my landscape pictures from a story on the John Muir trail as an essay, but when the group of editors got together, someone said that my pictures looked like postcards.

The landscape is like being there with a powerful personality and I'm searching for just the right angles to make that portrait come across as meaningfully as possible.

These days, most nature photographers are deeply committed to the environmental message.

One of the biggest mistakes a photographer can make is to look at the real world and cling to the vain hope that next time his film will somehow bear a closer resemblance to it.

Luckily, many other people tell me how they have had a particular landscape photograph of mine in their office or bedroom for 15 years and it always speaks to them strongly whenever they see it.

I think that cognitive scientists would support the view that our visual system does not directly represent what is out there in the world and that our brain constructs a lot of the imagery that we believe we are seeing.

I don't see this planet being... they're talking about how they're turning around the environmental problems here, but I think it's already too late.

There are nuclear weapons in China, Iran, Korea and Pakistan. It wouldn't take much to send a couple of warheads off on this planet somewhere that would cause a lot of environmental damage, then if you have got someone who wants to retaliate you have real problems.

Environmental concern is now firmly embedded in public life: in education, medicine and law; in journalism, literature and art.

There are a tremendous amount of environmental issues that are on the table.

I wanted to help raise awareness, so I created an environmental foundation called Just Within Reach.

Environmental quality was drastically improved while economic activity grew by the simple expedient of removing lead from gasoline - which prevented it from entering the environment.

The position I took at the time was that we hadn't really examined any of the potential environmental consequences of introducing genetically modified organisms.

But my point is that you design something in the end that precludes any unhealthy trading practices that are not going to serve your environmental or your economic objectives but now is not the time to do it.

Pushing production out of America to nations without our environmental standards increases global environmental risks.

This Bush administration has a growing credibility gap, maybe even a credibility chasm, on environmental policy. The President has lost the trust of the American people when it comes to the environment.

I assume we will have figured out a way to efficiently utilize solar energy and tied that to an efficient way to use nuclear energy in such a way that it doesn't pose a serious environmental issue.

Let me start by emphasizing that I am open to efforts to expedite environmental procedures for true emergencies or in other clear cases where current laws are needlessly burdensome.

One of the responsibilities faced by the Environmental Genome Project is to provide the science base upon which society can make better informed risk management decisions.

Complexity is one of the great problems in environmental design.

I reflect back 35 years ago, and look how far we have come in America with our environmental policy to improve the conditions of our air and water, and we have had some real successes.

There should be more attention paid to scientific research in the ecology area, and I think that such attention to proper environmental concerns would make the public feel much better about it.

The most meaningful engine of change, powerful enough to confront corporate power, may be not so much environmental quality, as the economic development and growth associated with the effort to improve it.

And I know that the younger generation is doing things that are so ingenious. And for them it's not a matter of a political belief or an environmental stance. It's really just common sense.

Well, for starters, we have to do more to create demand for new technologies that can reduce our dependence on foreign oil and environmental degradation.

Of the 55 refineries closed in America in the last 10 years, they were all closed for economic reasons, mostly oil company mergers. Not a single one was closed for environmental purposes or objections.

American culture is torn between our long romance with violence and our terror of the devastation wrought by war and crime and environmental havoc.