Terra Firma: Not as 'Firma' as You Might Think
By Our Green Team | Mar 5 2010, 15:17

Terra firma. Rock solid. On solid ground. While expressions like these suggest the Earth as a fixed and immutable place, reality says otherwise.

Over its 4.5-billion-year history, our planet has changed dramatically, sometimes at a slower-than-snail's pace, sometimes in sudden and cataclysmic fashion. The massive asteroid that slammed into the Earth 65 million years ago, for example, set off widespread fires, magnitude 10-plus earthquakes, devastating landslides and tsunamis, and a deadly global winter that killed off the dinosaurs and some 50 percent of all plant and animal families.

Today, astronomers track the heavens for signs of similar sized asteroids that might be headed our way. But giant hunks of rock in space aren't the only potential upheaval our planet might face.

Consider the magnitude 8.8 earthquake that struck Chile in late February. The massive quake not only toppled buildings and set off tsunamis (the most deadly occurring along the Chilean coast) but actually shifted the Earth's axis of rotation and shortened the length of a day by 1.26 millionths of a second .

Climate change could also affect how our planet spins by shifting the distribution of mass as ice caps melt. In fact, scientists say a warmer globe is also likely to be a more geologically active one as stresses on the surface change. At a conference in London last fall, researchers discussed a host of impacts that global warming could bring on, including earthquakes, landslides and tsunamis .

Then there's the Earth's old habit of reversing magnetic poles every so often. It appears we're long overdue for a switch , since the last one took place about 780,000 years ago and they were coming every 20,000 to 50,000 years or so apart before then. The possible effects such a geomagnetic flip might have on society is uncertain .

Society, on the other hand, is bringing about some planetary changes of its own. Even if you discount climate change, the human impact on Earth is already significant in many ways... and growing. Last year, an international team of researchers warned that we've already overstepped the planet's ability to cope in terms of climate, biodiversity loss and the nitrogen cycle, and are pushing the limits on ocean acidification, freshwater use, land system changes and stratospheric ozone depletion. Any one of these impacts could have huge ramifications for life on Earth - taken together, they're beyond worrisome.

In fact, a growing number of scientists today believe that humans have impacted the planet to such a degree that we've brought about a whole new geologic epoch: the Anthropocene .

It's all a far cry from life as we knew it in the 1970s, when fooling Mother Nature and inviting her wrath meant replacing butter with margarine , isn't it?

What Will a Warmer, Drier Future Mean for Us?
By Our Green Team | Feb 26 2010, 18:00

Of all our natural resources, two stand out from the rest: oil and water. That's because, unlike with many other materials, neither oil nor water can be easily replaced by something else.

Between the two, though, water wins hands-down as the most vital natural resource we have. We can imagine life - as radically different as it might be - without

oil... but life without water is both unimaginable and impossible.

And that's a problem because, in many places around the world, water is already becoming increasingly scarce. Wells in India are running dry as aquifers are depleted more quickly than they can be replenished by nature. Australian farmers are turning fruit trees into mulch because a years-long drought has slashed their water supplies. And officials in China are actually relocating millions of people whose farmlands are turning to desert.

There are a lot of reasons for all this water stress, including overpopulation in some places and unsustainable agricultural practices in others. But another factor will move to the center of the stage in coming years and decades: climate change.

Yes, some regions are expected to see more precipitation as the planet warms (though not necessarily the good kind, as it's increasingly likely to arrive in the form of torrential downpours and stronger hurricanes). But a significant portion of the globe - up to 38 percent, according to one study - is projected to grow much drier. These already-arid parts of the world can expect much more water stress in years to come, which will make life for their millions of human inhabitants even more difficult, if not impossible.

How will people adapt? Some, such as those on-the-move farmers in China, will have to relocate. Others might be able to adapt in place, turning instead to innovative strategies for life in a severely water-constrained world: practices like drip irrigation or xeriscaping-style agriculture. If you live in a dry part of the planet that's likely to get drier, you might want to think about what adaptations could work best for you.

In fact, that's something we should all consider, wherever we live. Global warming is likely to bring many changes we can't predict, and those could make for a radically different environment and lifestyle for many of us. Other factors - scarcer, more expensive oil, for example - could also affect the way we live in the years to come, so thinking about our options is a smart thing to do.

Look at it this way: if you live in a hurricane-prone area, you probably keep plenty of batteries and bottled water on hand in the months between June and November. And if you live in a colder, snowier climate, you know it's a good idea to have a well-stocked pantry and a supply of firewood if a blizzard traps you at home and leaves you without electricity for a week or so. Why shouldn't we all be giving the same sort of thought to making equally important preparations for life in a world altered by climate change?