We definitely don't want to go through another Ice Age or another natural cycle of global warming. Both happen over a long period of time. It would be disastrous for our civilization, and not just for us but many other species.
What I'm interested in is the conversations going on about the Anthropocene and what it means to view ourselves as a part of Earth's geological history.
We have to learn to become a new kind of entity on this world that has the maturity and the awareness to handle being a global species with the power to change our planet and use that power in a way that is conducive to the kind of global society we want to have.
Earth's biosphere gave birth to humans and our thoughts, which are now reshaping its planetary cycles. A planet with brains? Fancy that.
Among the plausible niches for extraterrestrial life in our solar system, the clouds of Venus are among the most accessible and the least well explained.
There's eco-pragmatism, where you recognize, 'Yeah, we live on a planet that's permanently altered by humanity, and rather than seek to return to or preserve pure wilderness, we recognize that's an illusion, and we proceed under the new knowledge that we live, in fact, in a human-dominated planet.'
One of the weird things about modern physics is that we do find there are apparently these other dimensions that we don't directly experience that explain some aspects of the overall geometry and reality of our universe.
I think Pluto has to be considered among the places in the solar system that are possible homes for life.
As a kid, I became a total SF geek. It started in the 5th grade with Asimov's 'Lucky Starr' series of what would now be called 'young adult' novels of adventures in the solar system.
The future peopling of Mars is much more than a scientific endeavor. It is a step of historic and spiritual importance for the human race.
It is said that Mahatma Gandhi, when asked about Western civilization, remarked, 'I think it would be a good idea.' That's how I feel about intelligent life on Earth, especially when I think about the question of what truly intelligent life might look like elsewhere in the universe.
If we gutted NASA Earth Science, it wouldn't be NOAA or some other agency that would take the lead. It would be the Chinese and the Europeans and the Japanese.
I don't see it as coincidence that the great acceleration of the Anthropocene influences on Earth came during the same decades as our first exploration of the other planets.
I think chemists always think they know more than they know, because nature has a lot of possible pathways it can try.
In my Ph.D. thesis, written in 1989, I discussed the fact that when a civilization develops the technology to prevent catastrophic asteroid impacts, it marks a significant moment in the evolution of the planet.
If you were on the surface of Venus, assuming you could see the Sun, which, you know, would be hard because it's so cloudy there, but the Sun would actually rise in the west and set in the east. And, it would do so very, very slowly, because the planet rotates incredibly slowly.
The hallmark of the human species is great adaptability.
There is a real danger of unintended consequences, of encouraging people to give up. Pessimism, if it becomes a habit, can reinforce a narrative of unstoppable decline. If there is nothing we can do, that releases us from our obligations.
As long as we can imagine a better path, of course we are obligated to seek it. This is why unwarranted pessimism about our future is actually irresponsible.
When you think about alien intelligences making art, you then have to think about what art is and how bound up it is in the nature of consciousness. Why do we make art? And what can we expect to have in common with other creatures in universe?
We don't know that Venus had oceans, but there's every reason to believe it did.
I'm a strong advocate of new missions to Venus.
Earth is going to lose its oceans in the future, just as Venus did in the past. How long planets retain their oceans is a function of distance from the sun, all other things being equal.
I'm an astrobiologist, and I come from a planetary science background, so in a very broad sense, I study the evolution of planetary environments.
I do comparative studies of climate evolution, and the interactions between planetary atmosphere and surfaces and their radiation environment, and try to understand the environmental factors that can affect a planet's habitability and how they change over time.
