As Americans are getting ready to cast their votes for the next occupant of the White House, let's step back from the heated political debate to focus on an issue that should — even if it doesn't — bring people together: the state of our planet.
I was in Rio de Janeiro last week, site of this year's Olympics. I grew up there, and was immensely proud of the spectacular success of the games. Despite the extreme negativity of media reports, the city came through and offered quite a show for the world to enjoy.
Last weekend, however, the scene changed. A cyclone off the coast of Rio caused major havoc at the famous Copacabana and Ipanema beaches.
Waves crossed the sand and roads and hit high-end buildings that house apartments worth millions of dollars, filling underground garages with water and tons of sand, damaging kiosks and sports equipment along the shoreline. No one remembers anything like this in the past 50 years. People stood by the sand-covered walkways with puzzled looks on their faces, a cross between amazement and fear. Events like this elicit nature's awesome power — and our ultimate fragility. The recent earthquake in Italy that killed at least 15 people brings this fragility into much more dramatic focus.
Given that the huge waves in Rio were an isolated event, it would be incorrect to attribute their power to global warming. Eyes are open now, however, that will follow any pattern over the next few years. Cyclones are beginning to occur in the southern coast of Brazil, an unprecedented phenomenon. If their incidence increases, the conclusion should be clear for those who want to see it. Rio is a city of 6 million people, about the same population as Brooklyn, Queens and Manhattan put together. In fact, New York City is another overpopulated region exposed to rising sea levels. There are many like it around the world. The thought of having massive population displacement from the coast to the interior is the stuff of dystopic sci-fi nightmares.
Over the last century, the sea level rose by about 6.7 inches. The rate for the last decade is nearly double that — double the rate of the whole last century.
There are two parts to the global warming debate: first, whether the global temperature is rising; second, whether this rise is human-induced. There is no question that the first is answered in the affirmative: The world is warming up. The evidence is overwhelming. Here's a list compiled by NASA. Although the vast majority of scientists also agree that this rise is human-induced, some insist in disagreeing, citing absurd arguments ranging from scientists wanting to get grants, or being a bunch of liberals with a green agenda, etc. So, for the sake of going beyond the discord, let's just consider the first part of the question, the rising global temperatures and their impact on our future.
The planet is a finite system. It was here well before we were, being formed some 4.6 billion years ago. Humans, by contrast, emerged around 200,000 years ago. If we were to compress 4.6 billion years into one day, humans appeared at 23:59:56 hours, or four seconds before midnight. We are the latest newcomers here, even if we think we rule the place. The point is, Earth has existed for much longer than we have — and will continue to exist if we disappear. Yet, our presence here has been so intense, so predatory, that we now live in what many call the Anthropocene — causing irreversible changes to the planet. To deny this seems incomprehensible in face of the evidence.
We are at a crossroads. Humanity must decide what kind of planet it wants to live on in the next few decades. Population growth remains a key issue, given that the numbers are mounting toward an unsustainable amount. Plus, more people means more resource use: more water, more food, more fuel. Where is all this going to come from? Should we blindly trust technology to rescue us? The recent findings that GMO foods are not any better than normal agricultural techniques don't bode well for this kind of expectation.
Arguments like these make people uncomfortable, annoyed or just plain angry. Change, when forced from the outside, especially by arguments you don't like, is never welcome or easy. People tend to wait until there's no other way out. The trouble with planetary change is that it is gradual and, thus, not scary enough to move people toward life-changing decisions. Change needs to come from a firm grasp of the situation, starting from an ability to think critically about the available information and from a commitment to make a difference at the individual level. Not by waiting for whom will get elected — whether the candidate who doesn't want to believe in planetary change or the one who does — but by thinking less selfishly about our individual needs, our bank accounts and investments, or the kinds of food we like to eat, or the kind of baths we like to take. By trying to make a difference — first alone and then for the family, for the community, for the country and, finally, for the planet.
Thoughts of planetary exodus or colonization of other planets aside — stuff that stands far away in the future — our problems are right here and right now, affecting us globally.
Marcelo Gleiser is a theoretical physicist and writer — and a professor of natural philosophy, physics and astronomy at Dartmouth College. He is the director of the Institute for Cross-Disciplinary Engagement at Dartmouth, co-founder of 13.7 and an active promoter of science to the general public. His latest book is The Simple Beauty of the Unexpected: A Natural Philosopher's Quest for Trout and the Meaning of Everything. You can keep up with Marcelo on Facebook and Twitter: @mgleiser