There is not a well-funded campaign among scientists to say, "Look, here's the evidence. You can read it yourself. Here are the facts. We're not making this up."
The climate has been changing. Of course it [has]. Evidence throughout history, [which] we can assess, especially during human history, shows there have been ups and downs. But the last ten thousand years have been relatively stable compared to now.
The burning of fossil fuels has altered the amount of carbon dioxide in the atmosphere so rapidly and so abundantly that now, we are driving not just the warming trend, not just the sea level rise that is a consequence of the warming trend that is melting polar ice and alpine ice, but also [ocean acidification].
We have an atmosphere that is roughly 21% oxygen. The rest of it is largely nitrogen. There's just enough carbon dioxide (CO2) to drive photosynthesis. That has been, throughout the history of our species, pretty stable. Until recently.
We have the capacity to alter the nature of nature. No, we don't have just the capacity - we are altering the nature of nature, the natural systems that cause the planet to function in our favor.
If we have a hope of really understanding our place in nature and of carving out a place for ourselves that is sustainable, it's primarily because of the new level of communication. It used to be, 'What you don't have in your mind, you have on your shelf.' But now we have the Web.
The very energy sources that have gotten us to where we are now are also, if we continue doing what we're doing, a shortcut to the end of all that we hold near and dear.
When you think about the real cost of so-called cheap energy that has driven our prosperity to unprecedented levels, for some of us, to our horror, we've realized that this has the potential for burning brightly and then snuffing out.
Never before have we known what we know.
Throughout all of human history we've enjoyed certain benign circumstances: an envelope of atmosphere, an envelope of temperature. A kind of resilience that if you cut down trees, then they'll grow back. You take fish, they recover. You put stuff into the atmosphere that you know is not good for us, but we can still breathe. We haven't awakened, generally, to the sense of urgency that does exist.
When I first ventured into the Gulf of Mexico in the 1950s, the sea appeared to be a blue infinity too large, too wild to be harmed by anything that people could do.
We have found ways to capture, kill and market ocean wildlife on an unprecedented scale. It's an absolute catastrophe.
The Exxon Valdez spill triggered a swift and strong response that changed policies about shipping, about double-hulled construction. A number of laws came into place.
There is an enormous amount to be learned about the sea; like most wildernesses, it has great potential.
The sudden release of five million barrels of oil, enormous quantities of methane and two million gallons of toxic dispersants into an already greatly stressed Gulf of Mexico will permanently alter the nature of the area.
We couldn't go to the moon on whale oil. We don't have the capacity yet to consider doing such things as harnessing current sunlight. We're burning ancient sunlight in order to get us to where we now are. But it's costly.
We want to believe that we can continue doing what we've done for the past thousand years and not worry about the consequences coming back to us.
We still have the illusion that the ocean will recover. That even if we do have to lose sharks, people don't understand why this matters. The evidence is in front of us, and we fail to take it in and say, "Now I get it. Now I understand."
Even our rules and regulations, our laws, our policies, favor the destructive nature of taking too much from the ocean and using techniques that are horribly destructive. We know they don't work. We know it's not sustainable.
There are a lot of smart creatures out there. Dolphins, elephants, and whales are smart. And there are some really smart birds. I know some really intelligent fish. But they cannot know what humans know and are incapable of inflicting as much damage.
Ice ages have come and gone. Coral reefs have persisted.
Photosynthetic organisms in the sea yield most of the oxygen in the atmosphere, take up and store vast amounts of carbon dioxide, shape planetary chemistry, and hold the planet steady.
I love music of all kinds, but there's no greater music than the sound of my grandchildren laughing; my kids, too.
Humans are the only creatures with the ability to dive deep in the sea, fly high in the sky, send instant messages around the globe, reflect on the past, assess the present and imagine the future.
Globally sharks have been killed for their fins, for their cartilage, for their livers, for their meat. But mostly what has driven some species of sharks to near extinction - including the hammerhead shark - is the new luxury taste for shark fin soup.
